The World of Ham Radio CD-ROM From lwbyppp@epix.net Thu Mar 07 10:04:01 1996 From: j0ker@hol.GR (Iraklis Mavrokefalos) Newsgroups: rec.radio.amateur.antenna Subject: (none) Date: 4 Mar 96 13:01:30 GMT Message-ID: <199603041301.LAA17225@prometheus.hol.gr> unsubscribe from Ham-Ant Mailing List and Newsgroup ******************************************************** * Iraklis Mavrokefalos * E-Mail:j0ker@prometheus.hol.gr * NOTICE j0ker with zero (0) not with an Oou (o) * Don`t ask, just do it !!! ******************************************************** From lwbyppp@epix.net Thu Mar 07 10:04:01 1996 From: nickb@alpine (Nicholas Barbieri) Newsgroups: rec.radio.amateur.antenna Subject: .5 wave 2m/440? Date: 6 Mar 1996 14:42:35 GMT Message-ID: <4hk88r$rs5@spock.asic.sc.ti.com> Some time ago, I remember seeing a 1/2 wave antenna for 2m that was about the same length as a 10m 1/4 wave whip. It was usually mounted on a ball or bumper mount, and had good gain over a 1/4 wave. Does anybody know what type of design it was? Is there such a configuration for dual band 144/440 MHz? -- Nick Barbieri, KB6QI Texas Instruments ASIC Engineering email: nlb1@ti.com From lwbyppp@epix.net Thu Mar 07 10:04:02 1996 From: landisj@nad.com (Joe Landis - Systems & Network Mgr) Newsgroups: rec.radio.amateur.antenna Subject: Re: 900 Mhz Beam needed Message-ID: <1996Mar1.125517.456@nad.com> Date: 1 Mar 96 12:55:16 EST References: <4gvr1b$5ur@hpbs2500.boi.hp.com> Distribution: world In article <4gvr1b$5ur@hpbs2500.boi.hp.com>, brayl@boi.hp.com (Brian Rayl) wri tes: > I am building some link radios on 900 MHz for point to point > and plan to use low power (about 10 MW). Who has some good deals > on these. I used to get stuff from Down East Microwave. They > used to have some nice loop yagi antana for 900 and 1200 MHz. > they no longer seem to be around. > Any info would be a great help. > > Brian Rayl N7MOE Down East is still around. They just moved to Frenchtown, NJ. (908) 996-3584 Joe - AA3GN -- Joe Landis - Systems and Network Manager - North American Drager - Telford, PA landisj@nad.com ..speaking only for myself, of course.. From lwbyppp@epix.net Thu Mar 07 10:04:03 1996 From: raiar@inlink.com (Gary V. Deutschmann, Sr.) Newsgroups: rec.radio.amateur.antenna Subject: Re: 900 Mhz Beam needed Date: Tue, 05 Mar 1996 23:03:48 GMT Message-ID: <4higpp$fo3@news1.inlink.com> References: <4gvr1b$5ur@hpbs2500.boi.hp.com> <31367655.1856382@news2.cts.com> forsberg@cts.com (Bruce W. Forsberg) wrote: >brayl@boi.hp.com (Brian Rayl) wrote: >>I am building some link radios on 900 MHz for point to point >>and plan to use low power (about 10 MW). Who has some good deals >>on these. I used to get stuff from Down East Microwave. They >>used to have some nice loop yagi antana for 900 and 1200 MHz. >>they no longer seem to be around. >>Any info would be a great help. >I think the company split. The company that sells the loop Yagis is called >Directive Systems. I just bought one of their 900 MHz loop yagis for 900 MHz. I >got mine from PC Electronics. They can be reached at 818-447-4565. >73 Bruce WB6IZG Sorry, I couldn't resist myself. How do you keep a fully assembled 900MHz beam from getting lost in the mail? After all, isn't it smaller than a cigarette! Hi Hi ;-) TTUL Gary From lwbyppp@epix.net Thu Mar 07 10:04:05 1996 From: hamop@aztec.asu.edu (CHARLES J. MICHAELS) Newsgroups: rec.radio.amateur.antenna Subject: Re: 9:1 Baluns Date: 2 Mar 1996 04:08:22 GMT Message-ID: <4h8hjm$rir@news.asu.edu> Gary said - One other thing that I cannot figure the relationship thereof, is that when talking to stations that are polarized opposite to me, I don't get that cross-polarization warble that is so evident on local QSOs when one is vertical and one is horizontal on SSB. I attribute it to the 450 ohm ladder being an integral part of the transmitting (or receiving) antenna. Gary, When a signal is reflected/refracted by the ionosphere it becomes essentially eliptically polarized i.e. it consists of a mixture of varying strengths of all polarizations. Most of the fading of DX signals is a result of your antenna 's polarization corrosponding or not corresponding to the dominant polarization of the signal at various times. Charlie, W7XC -- From lwbyppp@epix.net Thu Mar 07 10:04:06 1996 From: n7ws@azstarnet.com (Wes Stewart) Newsgroups: sci.astro.amateur,rec.radio.amateur.space,rec.radio.amateur.misc,rec.radio.amateur.homebrew,rec.radio.amateur.equipment,rec.radio.amateur.antenna,misc.invest.technical,misc.invest.stocks,misc.invest.funds,misc.invest.canada Subject: Re: Announsing: Technology Patent Available For Purchase Date: Mon, 4 Mar 1996 20:50:45 LOCAL Message-ID: References: <4hdlvj$kvv@sun.sirius.com> <4hfqtn$6kb@murrow.corp.sgi.com> In article <4hfqtn$6kb@murrow.corp.sgi.com> jimf@zoinks.corp.sgi.com (Jim Fell ows) writes: >In article , >gherbst@msn.com writes: >|> Paul, >|> >|> That's a very blatent claim you make. This patent went through with only >|> one need for clarification from the PTO. Obviously know one else sought >|> such a patent which is evidence by the PTO issuing me patent # 5457342. >|> >|> Those companies you mention have devices that are similar with respect to >|> cooling only if you care to follow the patents mentioned on my abstract. >|> However, NONE have developed the device I have NOR do they have a patent >|> on such a device. As such, I am the sole owner to pursue development of >|> this product or companies under infringement. >|> >|> Gaerhardt G. Herbst >|> >What I am wondering is what this has anything to do with amateur radio antenn as, >homebrew, space, etc.? The point is that this, and the preceding posts were >made to the amateur radio news groups. >Cooling of microprocessors, and your grandstanding of being awarded a patent are >of no interest to me or in any way pertinent to my interest in amateur radio. >And that is why the newsgroup(s) have those titles. >If you are looking for invetors, get a clue and do it somewhere else. >If you are simply so proud of yourself for being awarded a patent for what >appears to be anothers work, then HIP HIP HOORAY for you! Now grow up and go >away. >Jim Amen, Jim. If this thing works like this guy spells, he's got a tough sell. "Announsing", "blatent" and "know one else" indeed. I don't know what his device is, because searching for the number didn't work for me. Sounds like a Peltier device, but I guess it could be cold fusion. 73, Wes -- N7WS From lwbyppp@epix.net Thu Mar 07 10:04:08 1996 From: paul@laughton.com (Paul Laughton) Newsgroups: sci.astro.amateur,rec.radio.amateur.space,rec.radio.amateur.misc,rec.radio.amateur.homebrew,rec.radio.amateur.equipment,rec.radio.amateur.antenna,misc.invest.technical,misc.invest.stocks,misc.invest.funds,misc.invest.canada Subject: Re: Announsing: Technology Patent Available For Purchase Date: Tue, 05 Mar 1996 07:42:56 GMT Message-ID: <4hgr8o$p96@sun.sirius.com> References: <4hdlvj$kvv@sun.sirius.com> Reply-To: paul@laughton.com gherbst@msn.com wrote: >Paul, >That's a very blatent claim you make. This patent went through with only >one need for clarification from the PTO. Obviously know one else sought >such a patent which is evidence by the PTO issuing me patent # 5457342. >Those companies you mention have devices that are similar with respect to >cooling only if you care to follow the patents mentioned on my abstract. >However, NONE have developed the device I have NOR do they have a patent >on such a device. As such, I am the sole owner to pursue development of >this product or companies under infringement. >Gaerhardt G. Herbst Having too much time on my hands, I went and looked at your patent. The first part of the patent describes the exact CCD cooling method used for years by Santa Barbara Instruments (and others) for cooling CCDs. Your novel claim seems to be an IC cooler that is retrofitted to an existing, uncooled IC. From lwbyppp@epix.net Thu Mar 07 10:04:09 1996 From: "Thomas C. J. Sefranek" Newsgroups: sci.astro.amateur,rec.radio.amateur.space,rec.radio.amateur.misc,rec.radio.amateur.homebrew,rec.radio.amateur.equipment,rec.radio.amateur.antenna,misc.invest.technical,misc.invest.stocks,misc.invest.funds,misc.invest.canada Subject: Re: Announsing: Technology Patent Available For Purchase Date: 5 Mar 1996 12:31:07 GMT Message-ID: <4hhc6u$606@news.iii.net> References: <1996Mar5.000656.1@ssrl01> Westinghouse Semiconductor DOES indeed have a patent on TE coolers. (I don't know if they even exist anymore...) I have a large (4"-4" plate) made by them and it has a patent number on it. It has a nice fan on the back for moving the heat and embedded thermocouples for reading the two sides of the junction. I have used these devices at MIT for over 20 years now, and I'm curious as to the patent system that is being used by this guy who obviously had NO interest in the origional development of the device. Clearly a case of opportunism. Ah well Bill Gates can do it, why not this turkey? Tom WA1RHP From lwbyppp@epix.net Thu Mar 07 10:04:10 1996 From: n7ws@azstarnet.com (Wes Stewart) Newsgroups: sci.astro.amateur,rec.radio.amateur.space,rec.radio.amateur.misc,rec.radio.amateur.homebrew,rec.radio.amateur.equipment,rec.radio.amateur.antenna,misc.invest.technical,misc.invest.stocks,misc.invest.funds,misc.invest.canada Subject: Re: Announsing: Technology Patent Available For Purchase Date: Tue, 5 Mar 1996 22:06:25 LOCAL Message-ID: References: <4hdlvj$kvv@sun.sirius.com> In article <4hdlvj$kvv@sun.sirius.com> paul@laughton.com (Paul Laughton) write s: >From: paul@laughton.com (Paul Laughton) >Subject: Re: Announsing: Technology Patent Available For Purchase >Date: Mon, 04 Mar 1996 02:54:14 GMT >gherbst@msn.com wrote: [blah,blah... deleted] >I wonder how Mr Herbst slipped this one past the prior art >investigation? This technology has been around since the early 70's - >at least. For example, IBM and Amdahl main frames made extensive use >of it. Simple. He reinvented it first! From lwbyppp@epix.net Thu Mar 07 10:04:12 1996 Newsgroups: sci.astro.amateur,rec.radio.amateur.space,rec.radio.amateur.misc,rec.radio.amateur.homebrew,rec.radio.amateur.equipment,rec.radio.amateur.antenna,misc.invest.technical,misc.invest.stocks,misc.invest.funds,misc.invest.canada Subject: Re: Announsing: Technology Patent Available For Purchase Message-ID: From: gherbst@msn.com Date: Mon, 04 Mar 96 08:44:20 PDT References: Paul, That's a very blatent claim you make. This patent went through with only one need for clarification from the PTO. Obviously know one else sought such a patent which is evidence by the PTO issuing me patent # 5457342. Those companies you mention have devices that are similar with respect to cooling only if you care to follow the patents mentioned on my abstract. However, NONE have developed the device I have NOR do they have a patent on such a device. As such, I am the sole owner to pursue development of this product or companies under infringement. Gaerhardt G. Herbst From lwbyppp@epix.net Thu Mar 07 10:04:13 1996 From: gherbst@msn.com Newsgroups: sci.astro.amateur,rec.radio.amateur.space,rec.radio.amateur.misc,rec.radio.amateur.homebrew,rec.radio.amateur.equipment,rec.radio.amateur.antenna,misc.invest.technical,misc.invest.stocks,misc.invest.funds,misc.invest.canada Subject: Re: Announsing: Technology Patent Available For Purchase Date: Wed, 06 Mar 96 14:52:01 PDT Message-ID: References: <4hg97g$fef@cloner3.netcom.com> > I believe your final statement is too broad. You may "preclude others > from practicing your invention" is closer to the correct formulation. > Correct you Charles. Gerhardt G. Herbst From lwbyppp@epix.net Thu Mar 07 10:04:14 1996 From: gherbst@msn.com Newsgroups: sci.astro.amateur,rec.radio.amateur.space,rec.radio.amateur.misc,rec.radio.amateur.homebrew,rec.radio.amateur.equipment,rec.radio.amateur.antenna,misc.invest.technical,misc.invest.stocks,misc.invest.funds,misc.invest.canada Subject: Re: Announsing: Technology Patent Available For Purchase Date: Wed, 06 Mar 96 15:00:58 PDT Message-ID: References: <4hg97g$fef@cloner3.netcom.com> > Correct you Charles. > > Gerhardt G. Herbst > Whoops...I mean correct you are Charles... Gerhardt From lwbyppp@epix.net Thu Mar 07 10:04:15 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: sci.astro.amateur,rec.radio.amateur.space,rec.radio.amateur.misc,rec.radio.amateur.homebrew,rec.radio.amateur.equipment,rec.radio.amateur.antenna,misc.invest.technical,misc.invest.stocks,misc.invest.funds,misc.invest.canada Subject: Re: Announsing: Technology Patent Available For Purchase Date: Thu, 07 Mar 96 13:37:23 GMT Message-ID: <4hmp0u$nqk@crash.microserve.net> References: <1996Mar5.000656.1@ssrl01> <4hhc6u$606@news.iii.net> "Thomas C. J. Sefranek" wrote: >Clearly a case of opportunism. Ah well Bill Gates can do it, why not >this turkey? Bill Gates' success year after year is NOT the result of taking undue advantage of some helpless victim. Perhaps opportunism is just another catch-all phrase coined so the have-nots could better antagonize the haves? 73, Jack WB3U From lwbyppp@epix.net Thu Mar 07 10:04:16 1996 From: mluther@tamu.edu Newsgroups: rec.radio.amateur.antenna Subject: Re: Antenna arcing Date: 5 Mar 1996 17:50:20 GMT Message-ID: <4hhuss$61d@news.tamu.edu> References: <4hhelc$d2f@news.asu.edu> Reply-To: mluther@tamu.edu In <4hhelc$d2f@news.asu.edu>, hamop@aztec.asu.edu (CHARLES J. MICHAELS) writes : > >Always provide a DC path to ground so that charge is leaked off as >fast as it accumulates and it then does not get to sufficient voltage >to arc anywhere. > >Charlie, W7XC >-- Precisely, the reason for using SHUNT FED verticals, even in phased arrays! Mike W5WQN as a guest at leviathan.tamu.edu From lwbyppp@epix.net Thu Mar 07 10:04:17 1996 From: Cecil Moore Newsgroups: rec.radio.amateur.antenna Subject: Re: antenna efficiency Date: Sun, 3 Mar 96 12:32:01 -0500 Message-ID: References: <4ha20h$eff@chnews.ch.intel.com> <4hb3ng$347@newsbf02.news.aol.com> W8JI Tom writes: >That combo sounds good to me Cecil. It has a low initial SWR on at least >three popular bands! Great idea! What should we call it? ;-) Hi Tom, I'm not trying to steal G5RV's thunder, just improve on the original. For a 102 ft. dipole, there are current nodes on 40m and 20m-10m in the 75-87 ft feedline range. There are current nodes on all HF bands between 130-144 ft. All it takes is eight switches and some self-supporting loops of ladder-line mounted on a piece of plexiglas at the operating position to have a tunerless all-band antenna. Radio Adventure (Antennas West) is publishing my idea next issue. 73, Cecil, KG7BK, OOTC From lwbyppp@epix.net Thu Mar 07 10:04:18 1996 From: "Paul Christensen, N9AZ" Newsgroups: rec.radio.amateur.antenna Subject: Re: antenna efficiency Date: 5 Mar 1996 21:54:09 GMT Message-ID: <4hid61$1as@usenet.continental.com> References: <4ha20h$eff@chnews.ch.intel.com> To: cmoore@vegas.ch.intel.com >The moral is that a non-resonant antenna length can be >made to resonate and radiate just as efficiently as a >resonant antenna length. George Grammer himself could't have done a finer job in making this point. -Paul, N9AZ From lwbyppp@epix.net Thu Mar 07 10:04:19 1996 From: Hank Blackstock Newsgroups: rec.radio.amateur.antenna Subject: Re: antenna efficiency Date: 7 Mar 1996 12:42:27 GMT Message-ID: <4hmljj$10j@ionews.ionet.net> References: <4ha20h$eff@chnews.ch.intel.com> <4hid61$1as@usenet.continental.com> <4hkcs4$t3u@itnews.sc.intel.com> Cecil Moore wrote: >"Paul Christensen, N9AZ" wrote: >>>The moral is that a non-resonant antenna length can be >>>made to resonate and radiate just as efficiently as a >>>resonant antenna length. >> >>George Grammer himself could't have done a finer job in making this >>point. > >Thanks Paul, IMO almost all the loss problems associated with non- >resonant length ladder-line fed dipoles are in the network that >matches the balanced line to the unbalanced transmitter. I have >solved those problems and the results are almost unbelievable. My >tuner uses one parallel variable capacitor plus some toroids. > >73, Cecil, KG7BK, OOTC (not speaking for my employer) > > Another way to solve that problem is to use a Johnson Matchbox tuner instead of the Mickey Mouse tuners that are manufactured today. 73 Hank From lwbyppp@epix.net Thu Mar 07 10:04:20 1996 From: kb6ojs@earthlink.net (Steve Silverwood) Newsgroups: rec.radio.amateur.antenna Subject: Antenna for apartment Date: Tue, 05 Mar 1996 21:38:44 GMT Message-ID: <4hicb8$msv@bolivia.it.earthlink.net> Reply-To: kb6ojs@earthlink.net Here's the situation: I live in a downstairs apartment with a small backyard. We have a storage shed in the back, which means I may actually have a chance to set up a ham station again after being restricted to just my HT and 10m mobile rig for the past three years! But along with the apartment comes a limitation regarding what kind of antenna I can put up. Being a downstairs apartment, it means I have no access to the roof. Having the backyard means I can probably set up some kind of dipole or small beam, but I can't put it up very high. I also will have to operate very low power, in the QRP range, in order to avoid the interference problems that will no doubt come about with being in such close proximity to other apartments loaded with cheap electronics. ;-) Being a Tech Plus licensee, I will probably want to go for 40m CW operation. I've considered the Butternut bowtie beam antenna, but not sure about how it will perform in the above environment. If anyone has any suggestions as to commercial or homebrew solutions to this problem, I'm all ears! -- //Steve// Computer Associates CompuServe: 76703,3035 Fax: 714/557-1675 Internet: kb6ojs@earthlink.net Phone: 714/513-7236 America Online: KB6OJS Homepage: http://ourworld.compuserve.com/homepages/KB6OJS Personal homepage: http://www.earthlink.net/~kb6ojs From lwbyppp@epix.net Thu Mar 07 10:04:21 1996 From: Kootz@apollo.ph1.uni-koeln.de (Thilo Kootz) Newsgroups: rec.radio.amateur.antenna Subject: Re: Antenna model.soft (MININEX?) Date: Mon, 04 Mar 1996 14:43:03 GMT Message-ID: <4hevib$88c@news.rrz.uni-koeln.de> References: <4hc0hi$leu@ns.kern.com> Jesse Touhey wrote: >Hi Andrey, Contact W7EL (Roy). He has designed the best and most user >friendly software on the market. I assume you want to pay for it. 73s >Jesse I would not say that eznec is very user friendly, however it is very nice and once you got used to it, you will find it good ! Question to other eznec users: How do you model a bungalow roof, that is grounded? From lwbyppp@epix.net Thu Mar 07 10:04:22 1996 From: hamop@aztec.asu.edu (CHARLES J. MICHAELS) Newsgroups: rec.radio.amateur.antenna Subject: Re: Antenna model.soft (MININEX?) Date: 5 Mar 1996 12:36:30 GMT Message-ID: <4hhcge$bpr@news.asu.edu> Thilo Kootz wrote Question to other eznec users: How do you model a bungalow roof, that is grounded? You can set up a grid of wires approximating the roof dimensions and set the number of segments such that they occur at the same points where the wires dro/// cross. Remember that EZNEC assumes junctions of segments with the same position to be connected although they are not so shown in "view antenna". This reduces the number of wires required to for m an approximation of a surface. The segment lengths should of course be small relative to the wavelength. Confirmation from Roy might be appropriate here. Charlie, W7XC -- From lwbyppp@epix.net Thu Mar 07 10:04:22 1996 From: n7oo@azgate.nj7p.ampr.ORG (Jack Taylor) Newsgroups: rec.radio.amateur.antenna Subject: Antennas in PVC pipe Date: 5 Mar 96 03:17:06 GMT Message-ID: <3573@NJ7P> Today started to assemble a J-pole antenna for 224 MHz. Used number 12 solid wire and planned on enclosing it inside a length of 1 in dia PVC pipe. Using a grid dip meter, cut the antenna to resonate on 224. However upon inserting it inside the pipe, the resonant frequency dipped about 8 MHz lower! Went ahead and trimmed it some more until resonance inside the pipe was reached at 224 MHz. In this case at least, looks like PVC affects the VF of the physical dimensions by 0.91 as compared to free space. Has anyone else on the group have experience with placing an antenna inside of PVC pipe? 73 de Jack From lwbyppp@epix.net Thu Mar 07 10:04:24 1996 From: John Passaneau Newsgroups: rec.radio.amateur.antenna Subject: Re: Antennas in PVC pipe Date: Tue, 05 Mar 1996 09:14:44 -0800 Message-ID: <313C7684.6D69@leps.phys.psu.edu> References: <3573@NJ7P> Jack Taylor wrote: > > Today started to assemble a J-pole antenna for 224 MHz. Used number > 12 solid wire and planned on enclosing it inside a length of 1 in dia > PVC pipe. Using a grid dip meter, cut the antenna to resonate on 224. > > However upon inserting it inside the pipe, the resonant frequency dipped > about 8 MHz lower! Went ahead and trimmed it some more until resonance > inside the pipe was reached at 224 MHz. In this case at least, looks > like PVC affects the VF of the physical dimensions by 0.91 as compared > to free space. > > Has anyone else on the group have experience with placing an antenna > inside of PVC pipe? > > 73 de Jack Hi Jack: I've never used PVC pipe over an antenna, but I know the insolated wire does make a big differance. I thought I'd be smart and I substuted a lenght of #12 PVC insolated house wire for the stainless steel whip on a 2 meter mobile antenna, as it would be easer to trim to frequecy, and I would then just transfer the lenght to the steel whip. I did that and recheck the SWR and it was 4 to 1. It turned out that it was about 3 in too short and I had to buy a new steel whip and do it over. It was a good (?) example of dielectric loading. This happens at all frequencies, but is more noticable at higher frequencies. John Passaneau, WB8EIY, State College, Pa. From lwbyppp@epix.net Thu Mar 07 10:04:25 1996 From: jwc@col.hp.com (John Chapman) Newsgroups: rec.radio.amateur.antenna Subject: Re: Antennas in PVC pipe Date: 5 Mar 1996 22:07:25 GMT Message-ID: <4hidut$2te@nonews.col.hp.com> References: <3573@NJ7P> <313C7684.6D69@leps.phys.psu.edu> YES There is 3 Diff types of PVC pipe, white yellow & grey. I believe the lightest white is best, but even it will effect the resonance and must be comp ensated for. john, N0KIC From lwbyppp@epix.net Thu Mar 07 10:04:26 1996 From: gelleric@kafka.informatik.uni-stuttgart.de (Wolfgang Gellerich) Newsgroups: rec.radio.amateur.antenna Subject: Re: Antennas in PVC pipe Date: 6 Mar 1996 08:34:05 GMT Distribution: world Message-ID: <4hjilt$atm@zdi.informatik.uni-stuttgart.de> References: <3573@NJ7P> In article <3573@NJ7P>, n7oo@azgate.nj7p.ampr.ORG (Jack Taylor) writes: |> Today started to assemble a J-pole antenna for 224 MHz. Used number |> 12 solid wire and planned on enclosing it inside a length of 1 in dia |> PVC pipe. Using a grid dip meter, cut the antenna to resonate on 224. |> |> However upon inserting it inside the pipe, the resonant frequency dipped |> about 8 MHz lower! Went ahead and trimmed it some more until resonance |> inside the pipe was reached at 224 MHz. In this case at least, looks |> like PVC affects the VF of the physical dimensions by 0.91 as compared |> to free space. |> |> Has anyone else on the group have experience with placing an antenna |> inside of PVC pipe? |> As far as I know, the PVC molecules can become "activated" by certain frequencies, and PVC is generally not considered to be a good choice as material to construct antennas from. 73s, Wolfgang DJ3TZ From lwbyppp@epix.net Thu Mar 07 10:04:27 1996 From: s40402@abel.richland.cc.il.us (Joseph Utter) Newsgroups: rec.radio.amateur.antenna Subject: Re: Best 2M/70cm Mobile Antenna for Handheld Date: 6 Mar 1996 19:00:03 -0600 Message-ID: <4hlcej$guh@abel.richland.cc.il.us> References: Personally I use one from (of all places) Radio Shack. They have a nice tri-bander (6m, 2m, 70cm) with a mag-mount base and coax (unfortunatally to a motorola-male connector) for about $30. I really have 2 and am very pleased with the result for a non-expensive antenna. :-) You are right though about the many (thousands of) choices out there. Good luck and 73. Joe Utter, N9ZJL From lwbyppp@epix.net Thu Mar 07 10:04:28 1996 From: tom_boza@ccm.ch.intel.com (WB7ASR) Newsgroups: rec.radio.amateur.antenna Subject: Best way to insall a Rohn HBX tower Date: 5 Mar 1996 21:03:06 GMT Distribution: world Message-ID: <4hia6a$10bc@chnews.ch.intel.com> I purchased a Rohn HBDX-40 self-supporting tower with the three four foot long concrete base leg L-stubs. After I dig my base hole and install the rebar, what is the best way to install the three tower base leg L-stubs into the hole before the concrete is poored to insure they will be level and ture once the concrete has been poured? From lwbyppp@epix.net Thu Mar 07 10:04:29 1996 From: K5ESW@nando.net (Paul Ferguson) Newsgroups: rec.radio.amateur.antenna Subject: Re: Best way to insall a Rohn HBX tower Date: Thu, 07 Mar 1996 12:31:12 GMT Message-ID: <4hml0d$8sg@castle.nando.net> References: <4hia6a$10bc@chnews.ch.intel.com> <4hj3an$388@news1.sunbelt.net> flanders@znet.groupz.net (Jerry Flanders) wrote: >>I purchased a Rohn HBDX-40 self-supporting tower with the three >>four foot long concrete base leg L-stubs. After I dig my base hole >>and install the rebar, what is the best way to install the three tower >>base leg L-stubs into the hole before the concrete is poored to insure >>they will be level and ture once the concrete has been poured? I installed an HBDX-48. I mounted the legs to the base section and suspended the base above the concrete form using wooden beams across the form. The base section sits on the beams. Choose the beam height so that the base is the proper distance above the top of the future concrete pad. The legs extend down into the hole. Make it vertical and install some small guy wires to keep it in position. After pouring the concrete, you can make adjustments to the base section to insure it is vertical by playing with the guy wires 73, Paul Ferguson K5ESW@nando.net From lwbyppp@epix.net Thu Mar 07 10:04:30 1996 From: John M Sonley Newsgroups: rec.radio.amateur.antenna Subject: Re: Butternut HF Multiband Vertical Date: Fri, 1 Mar 1996 17:19:33 +0000 Distribution: world Message-ID: References: > >Butternut Vertical -- where can I buy the Butternut in the UK RadCom does not seem to carry any adverts for it John M Sonley G3XZV From lwbyppp@epix.net Thu Mar 07 10:04:31 1996 From: "William M. Bickley" Newsgroups: rec.radio.amateur.antenna Subject: Re: ButterNut Vertical...160 Capabilites ????? HELP! HELP!!!! Date: Tue, 05 Mar 1996 16:21:00 -0500 Message-ID: <313CB03C.B63@ix.netcom.com> References: <4hb8hi$4s9@newsbf02.news.aol.com> IIHHSS wrote: > > I have a new ButterNut Vertical. Does Butternut make a coil for this > antenna that will work 160 meters? Where might I get it? > > Looking forward to the answer... > > PATHi, Pat. Butternut DOES make a 160M coil for its verticals. I recently bought one, and was unable to make it work. I suspect my radials were just not long enough. The antenna is dyna mite otherwise. I'm astonished at how well it works on 80M. Oh, by the way, the bandwidth specified on the 160M coil is really, really nar row. If you're courious, I can look it up for you in the paperwork which came with the coil. I still have the coil, if you're interested. 73. Bill KF2ON From lwbyppp@epix.net Thu Mar 07 10:04:32 1996 From: iihhss@aol.com (IIHHSS) Newsgroups: rec.radio.amateur.antenna Subject: ButterNut Vertical...160 Capabilites ????? HELP! HELP!!!! Date: 2 Mar 1996 23:52:02 -0500 Message-ID: <4hb8hi$4s9@newsbf02.news.aol.com> Reply-To: iihhss@aol.com (IIHHSS) I have a new ButterNut Vertical. Does Butternut make a coil for this antenna that will work 160 meters? Where might I get it? Looking forward to the answer... PAT From lwbyppp@epix.net Thu Mar 07 10:04:33 1996 Newsgroups: sci.astro.amateur,rec.radio.amateur.space,rec.radio.amateur.misc,rec.radio.amateur.homebrew,rec.radio.amateur.equipment,rec.radio.amateur.antenna,misc.invest.technical,misc.invest.stocks,misc.invest.funds,misc.invest.canada From: jdc@cci.com (James D. Cronin) Subject: Cold fusion superconducting antennas (was: Announsing...) Message-ID: References: <4hfqtn$6kb@murrow.corp.sgi.com> Date: Wed, 6 Mar 1996 17:27:42 GMT In article , Wes Stewart wrote: >... >"Announsing", "blatent" and "know one else" indeed. I don't know what his >device is, because searching for the number didn't work for me. Sounds like a >Peltier device, but I guess it could be cold fusion. > >73, Wes -- N7WS Isn't it obvious: Homebrew superconducting cold fusion ham radio astronomy antenna equipment with investment potential for insider stock trader Canadians. (Apoligies in advance to our friends in VE land...) Ten points to the first person who cross-posts all this stuff to the alt.sex hierarchy. April 1 is closer than you think. 73...Jim N2VNO From lwbyppp@epix.net Thu Mar 07 10:04:34 1996 From: hamop@aztec.asu.edu (CHARLES J. MICHAELS) Newsgroups: rec.radio.amateur.antenna Subject: Re: Connector losses Date: 2 Mar 1996 03:51:05 GMT Message-ID: <4h8gj9$qv9@news.asu.edu> Graham Seale said - "To measure is to know"! Thompson (Lord kelvin ) said - 'IF you can't put a number on it you don't know what you are talking about' Charlie, W7XC -- From lwbyppp@epix.net Thu Mar 07 10:04:35 1996 From: hamop@aztec.asu.edu (CHARLES J. MICHAELS) Newsgroups: rec.radio.amateur.antenna Subject: Re: Connector losses Date: 6 Mar 1996 06:51:29 GMT Message-ID: <4hjclh$j9k@news.asu.edu> Tom says - >IF you can't put a number on it you don't know what you are >talking about' >Charlie, W7XC Good one Charlie, but how about the people that put numbers on things that can't have fixed answer? Or pull numbers out of their rear sides? Or mis-apply numbers? IMO, the most reliable answer anyone can give is "I don't know". That's the one answer in life we can absolutely depend on being correct. Anything else is suspect, h Tom, I was quoting Thompson (Lord Kelvin) - suggest you take it up with him! Charlie, W7XC -- From lwbyppp@epix.net Thu Mar 07 10:04:35 1996 From: w8jitom@aol.com (W8JI Tom) Newsgroups: rec.radio.amateur.antenna Subject: Re: Connector losses Date: 3 Mar 1996 08:56:10 -0500 Message-ID: <4hc8dq$bro@newsbf02.news.aol.com> References: <4h8gj9$qv9@news.asu.edu> In article <4h8gj9$qv9@news.asu.edu>, hamop@aztec.asu.edu (CHARLES J. MICHAELS) writes: >IF you can't put a number on it you don't know what you are >talking about' >Charlie, W7XC Good one Charlie, but how about the people that put numbers on things that can't have fixed answer? Or pull numbers out of their rear sides? Or mis-apply numbers? IMO, the most reliable answer anyone can give is "I don't know". That's the one answer in life we can absolutely depend on being correct. Anything else is suspect, hi. 73 Tom From lwbyppp@epix.net Thu Mar 07 10:04:36 1996 From: Steven B Reed Newsgroups: rec.radio.amateur.antenna Subject: Re: construction plan for a 2m beam Date: Wed, 06 Mar 1996 05:36:20 -0500 Message-ID: <313D6AA4.1BE@ix.netcom.com> References: <3139F8C8.3BAE@anet-dfw.com> <313D4E33.546F@sercon.ch> January 1995 QST Page 67 "A Five-Element Quad Antenna for 2 Meters" Built one myself and realy liked it. The article uses a wood beam and spreaders, cheap but not real permanent. I have read other posts on this ant when the article was first printed and most people want to use insulated wire, DON'T!! If you can avoid that temptation little else can go wrong with this design. Good luck and 73 -- Steven Reed KB8STB From lwbyppp@epix.net Thu Mar 07 10:04:38 1996 From: kr4tg@mindspring.com (mike del pozzo) Newsgroups: rec.radio.amateur.antenna Subject: Re: Cubical Quad Antennas for HF Date: Tue, 05 Mar 1996 00:27:13 GMT Message-ID: <4hg1p4$sj8@firebrick.mindspring.com> References: <4fsgkr$2v3@btr0x6.hrz.uni-bayreuth.de> <4gu415$797@B1FF.mindspring.com> <4gur91$3rl@nnrp1.news.primenet.com> <4h7lf7$q2a@opal.southwind.net> k0wa@southwind.net (Lee Buller) wrote: >Hey Guys.... >What about the GEM Quad out of Canada? Anyone have luck with them? I >am curous how a quad will withstand kansas winds and ice. >Lee K0wa >k0wa@southwind.net Hello Lee , The Quad antenna is not an indestructable instrument. You really have to consider that all elements are wire, and will attract alot of ice even in a " diamond " configuration. If you do go with a quad - make sure that EVERYTHING is heavy duty. The extra weight of the beam is well worth having it stay " up there " We usually dont have the same problems here in Atlanta. Gud Luck es 73 de KR4TG , Mike From lwbyppp@epix.net Thu Mar 07 10:04:39 1996 From: rcrgs@regcon.syr.servtech.com (Robert G. Strickland) Newsgroups: rec.radio.amateur.antenna Subject: Re: Cubical Quad Antennas for HF Date: Tue, 05 Mar 1996 08:55:49 -0500 (EST) Message-ID: <4hhe26$7pt@murphy2.servtech.com> References: <4fsgkr$2v3@btr0x6.hrz.uni-bayreuth.de> Charlie... I have been using a Lightning Bolt Quad for four years in Central NY. We get some strange weather here, and the LBQ has held up fine. I have the five band version, and I'm pleased with its performance. Be that as it may, I am planning to redesign/reconstruct it this summer. This does not reflect on the original design/construction. I've been modeling quads with EZNEC, and I'd just like to put my "knowledge" to use. LBQ uses aluminum welding wire. It is a bit difficult to work with, but its strength to weight ratio is excellent. While one cannot predict these things, I have the sense that it could stay up there for some time before anything happens to the wires - what ususally goes in a quad. Performance wise, quads are the best compact beam there is. You just can't get a better performing antenna in such a small space. ...Robert Robert G. Strickland KE2WY rcrgs@regcon.syr.servtech.com Syracuse, New York From lwbyppp@epix.net Thu Mar 07 10:04:39 1996 Newsgroups: rec.radio.amateur.antenna From: chronos@eskimo.com (Alan F. Jovanovich) Subject: Cushcraft AV5 info Needed Message-ID: Date: Thu, 7 Mar 1996 00:28:39 GMT I am in need of a manual / instruction sheet for an older Cushcraft model AV5 verticle. Specifically, I need to know the recommended number of radials their recommended lengths and size, and the tune up / adjustment procedure. If you have the info please Email me at: chronos@eskimo.com or fax it to me at 206-824-2751. Thanks. Alan, KA7DAT chronos@eskimo.com From lwbyppp@epix.net Thu Mar 07 10:04:40 1996 From: bob.albert@ledge.com (BOB ALBERT) Newsgroups: rec.radio.amateur.antenna Subject: Re: DIPOLE acting fishy Message-ID: <8BBE1E4.01B2002E84.uuout@ledge.com> Date: Fri, 01 Mar 96 08:04:00 -0800 Distribution: world Reply-To: bob.albert@ledge.com (BOB ALBERT) References: A 40 meter dipole may resonate on 15 meters, but won't be 50 Ohms. Hence, the high SWR. Don't worry about it, just use it and enjoy it. 73 DE K6DDX From lwbyppp@epix.net Thu Mar 07 10:04:41 1996 From: bcharbon@jupiter.cs.uml.edu (Brad Charbonneau) Newsgroups: rec.radio.amateur.antenna Subject: Erecting 100 ft tower on 800-900ft hill Date: 4 Mar 1996 20:24:16 GMT Message-ID: <4hfjhg$ij6@ulowell.uml.edu> Hi everyone, I am planning to erect a 100 ft tower (Rohn 55) on a hill of 800-900ft elevation. I realize that the winds will be strong up here, so I plan on reinforcing everything. This is my question: what can I do to the tower and / or antennas to make them stronger and more wind resistant? One ham suggested that I line the inner part of the antenna elements with rope in order to prevent the oscillations of the elements in the wind. He also recommended that I insert a thinner metal tubing piece inside part of the boom in order to make the boom stronger. I have wondered if increasing the amount of guying to the tower (ie every 15 ft rather than say every 25-20ft) w ould make the tower stronger against the wind... If anyone has any comments, or anything else they know of that I could do to make this setup more wind resistant, I'd really appreciate it. Maybe building my own antennas from scratch (w/ computer modeling prog) would make the strongest antennas...Any suggestions/info is greatly appreciated! Thanks in advance! 73, Brad NZ1Y From lwbyppp@epix.net Thu Mar 07 10:04:43 1996 From: VE4KLM Newsgroups: rec.radio.amateur.antenna Subject: feed point impedance calc for length of wire or tubing ? Date: Tue, 5 Mar 1996 11:56:27 -0600 Message-ID: Given a length of wire or tubing, is there a practical formula I can use to determine the feed point impedance for the following scenarios (the resistive component anyway) ? 1. length of wire or tubing, end fed 2. length of wire or tubing, center fed (dipole like) If the formula includes natural inductance & capacitance, even better. Thanks in advance, Maiko Langelaar VE4KLM --------------------- | SLM Software Inc. | | slmusr03@SLMSoft.CA | --------------------- From lwbyppp@epix.net Thu Mar 07 10:04:44 1996 From: cmoore@vegas.ch.intel.com (Cecil A. Moore~) Newsgroups: rec.radio.amateur.antenna Subject: Re: Feedpoint impedance - Extended double Zepp Date: 2 Mar 1996 04:19:35 GMT Distribution: usa Message-ID: <4h8i8n$kib@chnews.ch.intel.com> References: <4gsoag$lqc@kocrsv08.delcoelect.com> <4h5jfp$okf@nnrp1.news.primenet.com> In article <4h5jfp$okf@nnrp1.news.primenet.com>, Christopher Trask wrote: > BTW: There is nothing sacred about open feed line. Hi Chris, you're getting close to blaspheme, you know. :-) >A coax line >with a balun at the antenna feedpoint will work just fine, although coax >is a bit more lossy than open line. ELNEC gives the antenna feedpoint impedance for a 20m EDZ as 300-j1000. What kind of balun do you have in mind for that impedance? 73, Cecil, KG7BK, OOTC (not speaking for my employer) From lwbyppp@epix.net Thu Mar 07 10:04:45 1996 From: oopdavid@ubvms.cc.buffalo.edu (D.RODMAN) Newsgroups: rec.radio.amateur.antenna Subject: Force 12 info request Date: 5 Mar 1996 12:33 EST Distribution: world Message-ID: <5MAR199612334184@ubvms.cc.buffalo.edu> Can anyone give me a number or address for Force 12 antennas? I am looking for specific information on 20 m monobanders. Thanks, Dave. From lwbyppp@epix.net Thu Mar 07 10:04:46 1996 Newsgroups: rec.radio.amateur.antenna From: n4lq@iglou.com (Steve Ellington) Subject: Re: G5RV $24.95 Message-ID: References: <31367459.7466@hightec.com> Date: Sat, 2 Mar 1996 13:32:27 GMT Kinda hard to make'em stand up on their own though. Curt (curt@hightec.com) wrote: : Yes a full size"102Ft" G5RV for Just $24.95! Made by Van Gorden : Engineering. Work's 10-80 meters with antenna tuner and works better than : my hustler 5BTV Vertical! For more info E-MAIL curt@hightec.com or try : http://hightec.com/amnov/cvan.htm : 73 & good DX Curt, N9INK -- Steve Ellington N4LQ@IGLOU.COM Louisville, Ky From lwbyppp@epix.net Thu Mar 07 10:04:47 1996 From: rpmarkey@nbn.NET (Rick Markey) Newsgroups: rec.radio.amateur.antenna Subject: Gap DX-VI on 17M Date: 3 Mar 96 23:41:33 GMT Message-ID: <1.5.4b11.32.19960303234133.006af228@nbn.net> Does anyone have the modification to put the Gap DX-VI, VII, and VIII series of antennas on 17M? I beleive you modify the 12M tuning rod to accomplish thi s. TNX, de Rick KN3C From lwbyppp@epix.net Thu Mar 07 10:04:48 1996 From: jcl5@acpub.duke.edu (James C. H. Lee) Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc Subject: HELP: AM & FM signals Date: 5 Mar 1996 04:23:40 GMT Message-ID: <4hgfkc$7d6@news.duke.edu> I'm trying to receive an out-of-state but strong signal AM radio station (WSM-AM in TN to be exact) but have a hard time getting it. I can do OK from my car (with a fair amount of fuzz but at least recognizable, especially at night), but can hardly get it in the house. I currently have a loop antenna that came with the stereo attached for AM signals and a fancy-looking FM antenna that I bought (which helps improve FM signals) for the FM. Please, in your E-MAIL, tell me how to improve my reception in detail but not too technical. Also, how would I do the same for distant FM stations? Thanx to all who helps in advance! From lwbyppp@epix.net Thu Mar 07 10:04:49 1996 From: jcl5@acpub.duke.edu (James C. H. Lee) Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc,rec.radio.broadcasting Subject: HELP: AM & FM signals Date: 6 Mar 1996 01:27:29 GMT Distribution: world Message-ID: <4hipm1$ckd@vixen.cso.uiuc.edu> A question for all you radio experts out there. I am trying to receive an out-of-state but fairly strong AM signal (WSM-AM in Nashville to be exact) and do okay at night (though fuzzy) if I'm driving but have hard time getting it in the house. My stereo currently has a loop antenna that came from with it (which I attached for AM) and a FM stereo antenna that I brought which helps with FM reception. I want to know how can I improve my AM reception 24 hours (other than attaching an antenna onto my roof). How would I do the same for distant FM signals? Please in your e-mail, be detailed but not too technical. Thanx to all who help in advance! From lwbyppp@epix.net Thu Mar 07 10:04:50 1996 From: Charles Hobley <103575.1500@CompuServe.COM> Newsgroups: rec.radio.amateur.antenna,rec.radio.swap Subject: HF antenna Mobil Date: 4 Mar 1996 12:59:00 GMT Message-ID: <4hepek$k9f$2@mhafn.production.compuserve.com> HF Antenna mobil Texas Bug Catcher 6" coil with a 16" cap with break over hitch mount. $ 200.00 Contact me at (713) 931-9427 Email 103575,1500 @ compuserve.com Email CharlesHobley @ msn,com From lwbyppp@epix.net Thu Mar 07 10:04:51 1996 From: w8jitom@aol.com (W8JI Tom) Newsgroups: rec.radio.amateur.antenna Subject: Re: how can a duckie be 4-7db? Date: 5 Mar 1996 08:11:07 -0500 Message-ID: <4hhehb$8nu@newsbf02.news.aol.com> References: <4hgmgi$par@mark.ucdavis.edu> In article <4hgmgi$par@mark.ucdavis.edu>, szhall@rocky.ucdavis.edu (Jeff Hall) writes: > > I was reading an ad about rubber duckie for your hand held that have a >4-7db. and yet you can get a large out side 2 meter ant which the same >db. Can a rubber duckie really have that much db? "The smiley Antenna >Company has such antennas....please asnswer via e-mail...thanks, Jef > > They can be MINUS 4 to 7 dB, but certainly not plus (in reference to a 1/2 wave or isotropic radiator) !!!! Sound like the dB fairy waved his S unit at ole Smiley Antenna co. 73 Tom From lwbyppp@epix.net Thu Mar 07 10:04:52 1996 From: Hank Blackstock Newsgroups: rec.radio.amateur.antenna Subject: Re: how can a duckie be 4-7db? Date: 5 Mar 1996 22:24:26 GMT Message-ID: <4hieuq$nbj@ionews.ionet.net> References: <4hgmgi$par@mark.ucdavis.edu> <4hhehb$8nu@newsbf02.news.aol.com> w8jitom@aol.com (W8JI Tom) wrote: >In article <4hgmgi$par@mark.ucdavis.edu>, szhall@rocky.ucdavis.edu (Jeff >Hall) writes: > >> >> I was reading an ad about rubber duckie for your hand held that have a >>4-7db. and yet you can get a large out side 2 meter ant which the same >>db. Can a rubber duckie really have that much db? "The smiley Antenna >>Company has such antennas....please asnswer via e-mail...thanks, Jef >> >> > >They can be MINUS 4 to 7 dB, but certainly not plus (in reference to a 1/2 >wave or isotropic radiator) !!!! Sound like the dB fairy waved his S unit >at ole Smiley Antenna co. > I think some company's reference their antenna gain to a shielded dummy load buried 50 ft below ground. HankWA5JRH From lwbyppp@epix.net Thu Mar 07 10:04:53 1996 From: cmoore@vegas.ch.intel.com (Cecil A. Moore~) Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.equipment Subject: Re: How much RF pwr does an ant tuner consume? Date: 2 Mar 1996 17:04:18 GMT Distribution: world Message-ID: <4h9v2i$mp6@chnews.ch.intel.com> References: <4g2j6u$12e1@chnews.ch.intel.com> <4h40nl$2u46@info4.rus.uni-stuttgart.de> <1996Mar1.125809.21045@ke4zv.atl.ga.us> <4h73q9$7pq@cloner4.netcom.com> In article <4h73q9$7pq@cloner4.netcom.com>, Glenn Sparks wrote: >The problem isn't the tuner, the problem is the placement of the tuner, >and the loss of the feedline. Place the tuner at the antenna, so the >coax is loaded and fed as 50 ohms and the loss of the tuner will be >minimal. That's how I feed my mobile antenna - with an SGC230 mounted at the base of the antenna. It works great. However, for fixed installations, I think you will find the matched-line loss for reasonably priced coax is greater than the total loss in the less expensive open-wire line even with their sometimes "high" SWRs. The losses in the cheapest TV twin-lead are approximately the same as RG-8. Moving the tuner to the antenna may lessen or increase the losses in the tuner. Varying the length of the transmission line to reduce losses in the tuner is an option not available directly at the antenna. 73, Cecil, KG7BK, OOTC (not speaking for my employer) From lwbyppp@epix.net Thu Mar 07 10:04:54 1996 From: w7el@teleport.com (Roy Lewallen) Newsgroups: rec.radio.amateur.antenna Subject: Re: How much RF pwr does an ant tuner consume? Date: Mon, 04 Mar 96 17:46:35 GMT Message-ID: <4hfa83$qh9@nadine.teleport.com> w9cf@ptolemy.la.asu.edu: > [The power at the tuner output can be calculated using] >Pout = (|V|^2/Z0 + |I|^2*Z0) * (s/(1 + s^2)) >where |V| is the voltage magnitude and |I| is the current magnitude, >and Z0 is the real characteristic impedance, and s is the swr. . . Kevin, You're right, the power can be calculated from just |V|, |I|, and SWR. I hadn't thought of that combination, and will file it away to use again. Thanks for pointing it out! 73, Roy Lewallen, W7EL From lwbyppp@epix.net Thu Mar 07 10:04:55 1996 From: Cecil Moore Newsgroups: rec.radio.amateur.antenna Subject: Re: How much RF pwr does an ant tuner consume? Date: 5 Mar 1996 16:26:39 GMT Message-ID: <4hhpvv$9mq@itnews.sc.intel.com> References: <4hfa83$qh9@nadine.teleport.com> w7el@teleport.com (Roy Lewallen) wrote: >w9cf@ptolemy.la.asu.edu: >>Pout = (|V|^2/Z0 + |I|^2*Z0) * (s/(1 + s^2)) >You're right, the power can be calculated from just |V|, |I|, and >SWR. Hi guys, are these RMS values? Does this imply that V^2/Z0+I^2*Z0 is constant up and down the line in a lossless line? thanks and 73, Cecil, KG7BK, OOTC (not speaking for my employer) From lwbyppp@epix.net Thu Mar 07 10:04:56 1996 From: w7el@teleport.com (Roy Lewallen) Newsgroups: rec.radio.amateur.antenna Subject: Re: How much RF pwr does an ant tuner consume? Date: Tue, 05 Mar 96 22:51:18 GMT Message-ID: <4higfe$pm8@nadine.teleport.com> References: <4hfa83$qh9@nadine.teleport.com> <4hhpvv$9mq@itnews.sc.intel.com> In article <4hhpvv$9mq@itnews.sc.intel.com>, Cecil Moore wrote: >w7el@teleport.com (Roy Lewallen) wrote: >>w9cf@ptolemy.la.asu.edu: >>>Pout = (|V|^2/Z0 + |I|^2*Z0) * (s/(1 + s^2)) >>You're right, the power can be calculated from just |V|, |I|, and >>SWR. > >Hi guys, are these RMS values? Does this imply that V^2/Z0+I^2*Z0 >is constant up and down the line in a lossless line? Yes, and yes. Roy Lewallen, W7EL From lwbyppp@epix.net Thu Mar 07 10:04:57 1996 From: dmytrik@lglobal.com (Quirk) Newsgroups: alt.radio.pirate,rec.radio.broadcasting,rec.radio.amateur.antenna,alt.radio.free,alt.radio.college,rec.radio,rec.radio.amateur,rec.radio.amateur.misc,rec.radio.amateur.homebrew Subject: IDIO-AUDIO Toronto's Indie/Experimental Music Electronic Mailing List. Date: 1 Mar 1996 22:21:49 GMT Distribution: world Message-ID: <4h7t9t$82u@vixen.cso.uiuc.edu> Reply-To: dmytrik@lglobal.com Toronto residence beware, a new, suspicious union has formed. The perverse and demented members of the so-called IDIO-AUDIO mailing list plan to communicate with each other and inform one another about subversive events that play that bizarre eccentricity those people call music. They can tell one another which god forsaken vendors sell the filth they're looking for. They can discuss, review, announce, trade .... With this retched bohemia able to communicate -- Toronto will never be the same again. These people think they are too good to listen to the music everyone else listens to. The more people they have on idio-audio -- the more dangerous this lists becomes. They get more info, more views, reviews etc. and they can attract more people to their demented idiosyncratic events -- thereby increasing this threat to our fair city. All you need to be a part of idio-audio is an email account. It's so sinisterly simple that any one interested in this indie/experemental music and the debauched scene related it will one day be on the list. People who don't even have internet accounts can participate in the atrocity by using low cost BBSs that provide internet email now -- and then there's public access places like Local GlobalAccess where someone who doesn't even have a computer can get an email account. Every wacko in the Toronto area who likes this so-called Indie/Experimental music or is involved in it in any way has no excuse not to be on this list. They even have a web page: http://www.lglobal.com/~dmytrik/idio-audio.html They must be stopped! ..... Dmytri Kleiner -- Quirk P.S. Oh, Nevermind. dmytrik@lglobal.com http://www.lglobal.com/~dmytrik/idio-audio.html "Gravity lets (c) 1996 Idiosyntactix (tm) Toronto you down" IDIO-AUDIO -- Toronto's Indie/Experimental music electronic mailing list. Send email to majordomo@lglobal.com with the following command in the body of your message: subscribe idio-audio From lwbyppp@epix.net Thu Mar 07 10:04:58 1996 From: nx7u@primenet.com (Scott Townley) Newsgroups: rec.radio.swap,rec.radio.amateur.antenna Subject: Info/Items Wanted: Mobile HF: Icom AH-2 or SGC-230 Date: 5 Mar 1996 06:44:01 -0700 Message-ID: <4hhgf1$lsu@nnrp1.news.primenet.com> I'm looking to go mobile as it's apparent I'll never get a "real" antenna up anytime soon. Of most interest for a mobile HF antenna installation appear to be either the ICOM IC-AH2 (paired with an IC-735 which I already own), or the SGC-230/QMS2 gadget. I'm interested in any opinions, experiences, etc., from the community on either of these two items. And if anyone has one for sale, I'd be interested in that, too! Thanks in advance Scott Townley nx7u@primenet.com From lwbyppp@epix.net Thu Mar 07 10:04:59 1996 From: orrin@stinger.redshift.com (Orrin Winton) Newsgroups: rec.radio.amateur.antenna Subject: looking for Winton Bell ZL3AO Date: 4 Mar 1996 19:53:39 GMT Message-ID: <4hfho3$use@wing.redshift.com> Winton Bell, you sent me a note after reading one of my postings, and i want to respond, but the e-mail address in the FROM: field of your note is invalid, isn't even a real e-mail address. If you could pleawse send another note signed with your e-mail address i will respond. Thanks orrin@redshift.com From lwbyppp@epix.net Thu Mar 07 10:05:00 1996 From: philj@ecc-uky.campus.mci.net (Phillip Jockell) Newsgroups: rec.radio.amateur.antenna Subject: manual for 4BTV Date: 2 Mar 1996 13:18:20 GMT Message-ID: <4h9hqs$8pp@ns.campus.mci.net> Can anyone send/fax me a copy of the manual/info sheet on the 4BTV? A friend gave me one, but he had long since discarded the documentation. (How come people do that???) Thanks for ANY help - 73, phil - N4GWV From lwbyppp@epix.net Thu Mar 07 10:05:01 1996 From: Bud Simmons Newsgroups: rec.radio.amateur.antenna Subject: MFJ HF VERTICALS??? Date: 5 Mar 1996 17:52:31 GMT Message-ID: <4hhv0v$v2d@newsgate.sps.mot.com> Has anyone tried the MFJ vertical antennas? ARE THEY ANY GOOD? From lwbyppp@epix.net Thu Mar 07 10:05:02 1996 Newsgroups: rec.radio.amateur.antenna From: kingbp@ka1fqt.mv.com (Bryan King) Subject: Re: Mounting height of R5? Message-ID: Date: Tue, 5 Mar 1996 04:20:37 GMT References: <1996Feb23.201810.11807@schbbs.mot.com> <4grfu0$1rs@blackice.winternet.com> In article <4grfu0$1rs@blackice.winternet.com>, sholisky says: Would having the R5 6 - 8 feet away from trees and large rocks detune it? There's also an AR6 nearby that is even closer to the ground. I currently have my R5 mounted on a piece of 1.25" galvanized conduit that is 10' long. Its about 8' off the ground and in a small clearing on high ground. Its about 20' above my house in the backyard and about 50' from the house. Its far away from any powerlines or other noisy sources. Later this spring, I'm going to add another 10' section of conduit to raise the effective height of the antenna to 18' So far I've had good luck with this antenna in working DX. 73's Bryan From lwbyppp@epix.net Thu Mar 07 10:05:03 1996 From: rbrown@woodtech.com (Raymond A. Brown) Newsgroups: rec.radio.amateur.antenna Subject: Re: need plans for 6m antenna Date: 2 Mar 1996 21:21:59 GMT Message-ID: <4hae5n$ja9@news.paonline.com> References: <4gaqpe$884@news-e2a.gnn.com> <4gtc1j$lgi@news1.inlink.com> Gary V. Deutschmann, Sr. (raiar@inlink.com) wrote: : MMcanally@gnn.com (Mark McAnally) wrote: : : >Does anyone know of a source for a simple yet effective dipole or : >vertical 6m homebrew antenna? Thanks in advance KE4QKN in : >Milton, FL : : Hi Mark : : Check out my home page under Copper Cactus at : http://www.inlink.com/~raiar : The numbers you need to construct a single band 6-m J-Pole are the : same as for the multi-band. : I use J-Poles almost exclusively now, most are the mirror image J's : which for 6-m I installed it such that I can turn horizontal if need : be. If you don't see my Email, please respond to rbrown@woodtech.com. Thanks! _Ray_ KB0STN From lwbyppp@epix.net Thu Mar 07 10:05:04 1996 Newsgroups: rec.radio.amateur.antenna From: at738@FreeNet.Carleton.CA (David Toste) Subject: New home Attic Antenna? Help needed. Message-ID: Reply-To: at738@FreeNet.Carleton.CA (David Toste) Date: Mon, 4 Mar 1996 08:51:41 GMT Hello to all. Just join this newsgroup and haven't been able to find a FAQ so here I am asking 2 or 3 questions which I'm sure have been asked more then once. I've just bought a new home and I'll be moving in June. The house is just about built. The home is a new comunity, so as I'm sure you all know that in new homes people don't like major towers poping up and antennas everywhere. I won't have access to a fence yet not atleast until the summer/spring of 97, the back of the home is sorta still just mud and they are still working on building the other homes. What I want to do until I am able to rig a wire or two outside I wanted to rig something in the attic. I don't have the exact sizes but it's more or less 50x20ft and atleast 6 ft height, but the measurements could be alittle more. I won't know until I can get into the attic once I move in and know for sure. I'ld like to have something that I would work from 10-80m(ya I know 10m is useless just about now.) Anyone have any ideas as to what I could place up there? -- David Toste [VE3TOS] Internet - aa521@freenet.toronto.on.ca Don Mills, Ontario. SWLOGit - The Ultimate Shortwave Listeners ftp.virginia.edu /pub/swlogit/ Software. (Fidonet: 1:250/930) *NEW* http://www.interlog.com/~saturn/SWLOGit.html (SWLOGit Web Page) From lwbyppp@epix.net Thu Mar 07 10:05:05 1996 Newsgroups: rec.radio.amateur.antenna From: Curt Subject: PORCELAIN INSULATORS Message-ID: <313D0B9F.5B84@hightec.com> Date: Wed, 6 Mar 1996 03:50:55 GMT If you have an antenna project in mind for spring, i have some hard to find Birnbach Porcelain insulators for sale. They are about 8" long & about 1 1/2" around. These are great for SWL, Ham Hi-Power or any wire antenna. The price is $4.00ea plus shipping. To reach me: Curt@hightec.com or phone 317-862-1282 before 10pm EST or you can mail a check with approx $5.00 for shipping to Curt Haroutunian N9INK 7835 E Southport Rd. Indianapolis, IN. 46259 An E-Mail message to let me know your check is on the way will hold them for you as quantity is limited to 80 at the time of this post. From lwbyppp@epix.net Thu Mar 07 10:05:06 1996 Newsgroups: rec.radio.amateur.antenna From: "Martin Biallas" Subject: Q: How would a 80m Magnetic Loop antenna look like? Message-ID: <42386306@clobber.mos.unterland.de> Date: Sun, 3 Mar 1996 10:51:53 GMT Hello! Unfortunately I have no opportunity to establish a good 80m antenna. (I live i n a flat in a house that I dont own.) Recently I heard about an antenna called Mag netic Loop. It was said that this antenna typ allows -although it is worse than an h alf wave Dipol- nice QSOs. Or in other words: its better than nothing. :) Now my question is how must a magnetic loop for the 80m band look like? And co uld anyone send me (via email) the meassurements of that antenna? Maybe there are even www-sites which contain such a plan ... Thanks for any notices! Bye ... Martin --------->billy@picard.mos.unterland.de<---------- To get my PGP Pubkey send a mail with Subject 'SendPGP'. From lwbyppp@epix.net Thu Mar 07 10:05:08 1996 From: w7el@teleport.com (Roy Lewallen) Newsgroups: rec.radio.amateur.antenna Subject: Re: S Units Date: Mon, 04 Mar 96 18:03:38 GMT Message-ID: <4hfb83$qh9@nadine.teleport.com> References: <4gkmfu$4b2@newsbf02.news.aol.com> <4h02jm$20i@fountain.mindlink.net> <4h25da$cvd@news.service.uci.edu> <3139c03e.168283938@news.comox.island.net> In article <3139c03e.168283938@news.comox.island.net>, tmaldred@mail.comox.island.net (Thomas M. Alldread) wrote: >On 28 Feb 1996 18:03:22 GMT, jwkelley@e4e.oac.uci.edu (James W. KELLEY) wrote: >. . . >0.25 uV for a 10 dB Signal \ Signal + noise ratio. If one were to consider >the sensitivity >specification as roughly equivalent to an S zero threshold then it would >appear that a calibration >factor of 5 dB per S unit is the closest round number fit to the 10 dB >S/S+N sensitivity with a >calibration reference of S9=50 uV. >. . . Unfortunately, reaching this conclusion requires making two assumptions, neither of which is necessarily true. > A nice >quality of a 6dB/SU curve is that the RF input voltage doubles for each S >unit increase of signal >strength (representing increase of input power of 4 times for each >additional S unit) which would >be a practical rule-of-thumb to remember. It would, but since it isn't true, I don't recommend remembering it. > I think the current technology could support an improvement in the >calibration of S-meters. . . >An S meter tracking accuracy specification >should be included as part >of the overall specifications. > I hope the manufactures take steps to clear up this age old guess >meter confusion so that >radio amateurs have the ability to routinely measure signal strengths in a >reasonably accurate >manner in the near future. Possibly the amateur radio community may need >to lobby the manufactures >to give the issue some priority. In the meantime, why don't we just measure our S-meters instead of engaging in endless speculation and argument? An evening of simple work, a handful of 5% resistors, a few slide switches, a couple of connectors, and a little PC board material are all that are required to build a step attenuator. That and a steady signal source are all you need. An added advantage is that you can also use the same step attenuator with a switch to actually measure which antenna is better, and by how many dB. I do agree with Thomas that the only thing which will cause the manufacturers to make consistent S-meters is to convince them that the increase in sales will make it worth the effort. Personally, I'd rather see less than 6 dB/S-unit, and a step attenuator at the input. Roy Lewallen, W7EL From lwbyppp@epix.net Thu Mar 07 10:05:09 1996 From: sabinw@crpl.cedar-rapids.lib.ia.us Newsgroups: rec.radio.amateur.antenna Subject: S-Meter Cal Date: 4 Mar 1996 07:36:25 GMT Distribution: world Message-ID: <4he6hp$i2u@flood.weeg.uiowa.edu> Reply-To: SABINW@crpl.cedar-rapids.lib.ia.us In the early 1950's Collins Radio adopted the following rule for its S-meters: 100 microvolts open circuit from a 50 Ohm sig gen, or 50 microvolts meter reading on the sig gen meter, for S9. The S meter reference was set at 1 microvolt open circuit. This figures to 4.4 dB per S unit, or "approximately 4 dB per S unit", according to their receiver owner's manuals. Because of threshold effects in diode AGC detectors and gain variations in vacuum tube circuitry and calibration accuracy there was no attempt to be too nit-picky about this. Later solid state designs made it possible to achieve more reliable calibrations. One good approach is an internal calibrated noise source that can be used with a certain IF bandwidth to set an S9 level by pushing a button and adjusting a gain pot. The receiver could then be a pretty good field strength meter. This "built-in-test" is common in some equipment. From lwbyppp@epix.net Thu Mar 07 10:05:10 1996 From: burch@netline.net (Burch Akin) Newsgroups: rec.radio.amateur.antenna Subject: Re: shuttle communication on 2 meter Date: Mon, 04 Mar 1996 15:12:02 GMT Message-ID: <4hf150$cc7@tesla.netline.net> References: <00001fea+0000208c@msn.com> <4gqtvh$dpl@news.fwi.com> <4h2pq6$jav@chnews.ch.intel.com> tom_boza@ccm.ch.intel.com (WB7ASR) wrote: >Unless you have the "BIG" station, forget about working the shuttle. >They only talk with pre-determined scheduled contacts (schools), or >stations with the loudest signals ( EME arrays with 1KW amps). When >their above your horizon, there are about 200+ stations on the average >all calling them at the same time you are. The BIG signal will win!!! >WB7ASR... I disagree. A friend of mine has worked the Shuttle everytime it has had ham equipment onboard. He works it with 80watts into a 6 element beam (he uses two $10 rotators to aim the beam.) Granted a big station with be heard first, if you have a little patience you can work the shuttle without a "big" station. I know people who have made contact with the shuttle using 25watts into a groundplane! KE4ZQV Burch Akin From lwbyppp@epix.net Thu Mar 07 10:05:11 1996 From: Charles Bolland Newsgroups: rec.radio.shortwave,rec.radio.amateur.antenna,rec.radio.amateur.digital.misc,rec.radio.amateur.equipment,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.amateur.policy,rec.radio.amateur.space,rec.radio.noncomm,rec.radio.scanner,rec.radio.swap Subject: Re: Stand Alone Broadcast Radio Station Database - LW,MW,SW Date: 2 Mar 1996 21:35:10 GMT Message-ID: <4haeue$fkb@news.flinet.com> References: <4gttsh$82a@detroit.freenet.org> <4gvda8$ou@Speedy.grolier.fr> To: chuck@flinet.com Friends, I'm still sending out the Stand Alone Broadcast Radio Station Database to whomever wants it. I would like your mailing address and Email address for registration and possibly a future letter describing a more comprehensive database program for radio. All information will be kept confidential.. Just answer this posting to "chuck@flinet.com". The database has more than 4,000 records already and can be edited and updated. Hope to hear from you. Chuck KA4PRF From lwbyppp@epix.net Thu Mar 07 10:05:12 1996 From: lenrev@wwa.com (Len Revelle) Newsgroups: rec.radio.amateur.antenna Subject: Re: Strange Phenonomon on G5RV Date: Tue, 05 Mar 1996 06:17:57 GMT Message-ID: <4hgmks$aln@kirin.wwa.com> References: <4h3433$2nb@news.fwi.com> Years ago I took my brand new Heathkit HW-7 QRP rig to a friends to try a real antenna. The last antenna used was a long wire. Winds were getting high so I decided to go home and disconnected the longwire from the HW-7. When I inserted the coax connector back into Al's TR4B transciever the radio caught fire! We found a potted choke in the front end, presumably as protection, burnt to a crisp. The cause was presumed to be static built up by the wind. I've heard that people have been killed due to such discharges around other long line systems such as power line carrier cables, etc... macino@mail.fwi.com wrote: >Wow, > This one will get ya thinking. I live in Northern Indiana and last nite we had > thunderstorms and relatively spring like weather. I have an 80 meter length G5RV > strung between two trees. The antenna is stretched pretty taut and is about 35' > average in height. > Well, the thunderstorm left the area about midnight. By this morning the we ather > changed drastically and we had a wind chill of -30 degrees. In other words i t was > in Hoosier parlance 'whooping it up!' > I had pulled the PL-259 out of my HF rig last night and left it laying acr oss a > book. About 7:30 this morning I started hearing a 'snapping sound' about eve ry 15 > seconds. It was loud enough that the Jethro Tull CD that I had playing was b eing > interrupted by this 'snapping'. Low and behold I looked over in the directio n of the > PL-259 and the 'snapping' was actually an arc between the center pin and the > barrel of the connector. I lifted the end of the cable away from the book, a nd > isolated it from anything combustible. The phenonomon continued on for about > 35 more minutes. During this time, it was snowing, cleared, and flurried aga in. > I guess the reason for the post, is that even in a weather situation where it was > not 'lightning and thunder' conditions, and ungrounded open end feedline can > bring you a real surprise. If I had been working with combustibles, this cou ld have > been a 'post mortem'. Anybody else ever see this? > Jim WD9AHF > From lwbyppp@epix.net Thu Mar 07 10:05:14 1996 Newsgroups: rec.radio.amateur.antenna From: n4lq@iglou.com (Steve Ellington) Subject: Re: Strange Phenonomon on G5RV Message-ID: References: <4h3433$2nb@news.fwi.com> <1996Mar1.151643.22032@ke4zv.atl.ga.us> Date: Sat, 2 Mar 1996 13:30:42 GMT I've had this happen a lot with center fed Zepps. 4 years ago a thunderstorm was about 20 miles away and my tuner began snaping loudly. I could faintly see the lightning. So waiting for a pause, I quickly reached behing the antenna tuner and yanked the feeders off their binding post. When I did, I felt a slight tingle. The next day after I got to work, I glanced at my wrist watch to check the time and volia, the watch had stopped on the very minute that I had unhooked the antenna. So I took my nice Citizens, electronic watch to the jewler who pronuced it dead. The chip had blown. Now in your case, it could just be those Jethrol Tull tunes attracting the charge. You remember how flute music was used once to attract rats? Well.......hmmmm. -- Steve Ellington N4LQ@IGLOU.COM Louisville, Ky From lwbyppp@epix.net Thu Mar 07 10:05:15 1996 From: mfp@aros.net (M.F.P.) Newsgroups: rec.radio.amateur.antenna Subject: Re: Strange Phenonomon on G5RV Date: 5 Mar 1996 17:47:26 GMT Message-ID: <4hhune$21q@news.aros.net> References: <4h3433$2nb@news.fwi.com> <4h5rlh$cs8@news.one.net> In article <4h5rlh$cs8@news.one.net>, k8cxm@one.net says... > >macino@mail.fwi.com wrote: > >>Wow, >> This one will get ya thinking. I live in Northern Indiana and last nite we had >> thunderstorms and relatively spring like weather. I have an 80 meter length G5RV >> strung between two trees. The antenna is stretched pretty taut and is about 35' >> average in height. >> Well, the thunderstorm left the area about midnight. By this morning the weather >> changed drastically and we had a wind chill of -30 degrees. In other words it was >> in Hoosier parlance 'whooping it up!' >> I had pulled the PL-259 out of my HF rig last night and left it laying across a >> book. About 7:30 this morning I started hearing a 'snapping sound' about every 15 >> seconds. It was loud enough that the Jethro Tull CD that I had playing was being >> interrupted by this 'snapping'. Low and behold I looked over in the direction of the >> PL-259 and the 'snapping' was actually an arc between the center pin and the >> barrel of the connector. I lifted the end of the cable away from the book, and >> isolated it from anything combustible. The phenonomon continued on for about >> 35 more minutes. During this time, it was snowing, cleared, and flurried again. >> I guess the reason for the post, is that even in a weather situation where it was >> not 'lightning and thunder' conditions, and ungrounded open end feedline can >> bring you a real surprise. If I had been working with combustibles, this could have >> been a 'post mortem'. Anybody else ever see this? > >> Jim WD9AHF >>Here's a simple way to HELP isolate the feeder, ladder line, instead of using ladder all the way to your tuner, put a 1:1 balun at the base of the vertical ladder line, then run RG/8 coax cable into your tuner or rig... gives a little better isolation ratios...Plus, you can ground the Coax feed to direct grounding rods...at ground level... Just a thought....anyone else build on this??? From lwbyppp@epix.net Thu Mar 07 10:05:17 1996 Newsgroups: rec.radio.amateur.antenna From: pringle@ccsu.ctstateu.edu (Pringle) Subject: Re: Strange Phenonomon on G5RV Message-ID: References: <4h3433$2nb@news.fwi.com> <4h5rlh$cs8@news.one.net> <4hhune$21q@news.aros.net> Date: Wed, 6 Mar 1996 14:49:15 GMT In article <4hhune$21q@news.aros.net>, mfp@aros.net (M.F.P.) says: > >In article <4h5rlh$cs8@news.one.net>, k8cxm@one.net says... >> >>macino@mail.fwi.com wrote: >> >>>Wow, >>> This one will get ya thinking. I live in Northern Indiana and last nite w e >had >>> thunderstorms and relatively spring like weather. I have an 80 meter lengt h >G5RV >>> strung between two trees. The antenna is stretched pretty taut and is abou t >35' >>> average in height. >>> Well, the thunderstorm left the area about midnight. By this morning the >weather >>> changed drastically and we had a wind chill of -30 degrees. In other words >it was >>> in Hoosier parlance 'whooping it up!' >>> I had pulled the PL-259 out of my HF rig last night and left it laying >across a >>> book. About 7:30 this morning I started hearing a 'snapping sound' about >every 15 >>> seconds. It was loud enough that the Jethro Tull CD that I had playing was >being >>> interrupted by this 'snapping'. Low and behold I looked over in the >direction of the >>> PL-259 and the 'snapping' was actually an arc between the center pin and >the >>> barrel of the connector. I lifted the end of the cable away from the book, >and >>> isolated it from anything combustible. The phenonomon continued on for >about >>> 35 more minutes. During this time, it was snowing, cleared, and flurried >again. >>> I guess the reason for the post, is that even in a weather situation >where it was >>> not 'lightning and thunder' conditions, and ungrounded open end feedline >can >>> bring you a real surprise. If I had been working with combustibles, this >could have >>> been a 'post mortem'. Anybody else ever see this? >> >>> Jim WD9AHF > >>>Here's a simple way to HELP isolate the feeder, ladder line, instead of >using ladder all the way to your tuner, put a 1:1 balun at the base of the >vertical ladder line, then run RG/8 coax cable into your tuner or rig... give s >a little better isolation ratios...Plus, you can ground the Coax feed to >direct grounding rods...at ground level... > >Just a thought....anyone else build on this??? > The exact same thing happened to a friend of mine during a blizzard this winter (same storm?). We figure the cold dry air coupled with snow caused a static charge to build up. Good thing that you had your rig unplugged! Bill - N1WBO From lwbyppp@epix.net Thu Mar 07 10:05:18 1996 From: COMUNICA@mvax1.red.cinvestav.MX (ESTUDIANTES DE COMUNICACIONES) Newsgroups: rec.radio.amateur.antenna Subject: switches Date: 5 Mar 96 21:29:00 GMT Message-ID: <199603052135.NAA26999@UCSD.EDU> Hello everyone. I wonder if you know about commercial devices that let me switch between two antennas whose transmition lines are 75 ohms. Any help would be very appreciated. Benjamin. email: bmillan@vader.mixbaal.udg.mx From lwbyppp@epix.net Thu Mar 07 10:05:19 1996 Newsgroups: rec.radio.amateur.antenna From: n4lq@iglou.com (James Casey) Subject: Re: switches Message-ID: References: <199603052135.NAA26999@UCSD.EDU> Date: Tue, 5 Mar 1996 21:48:30 GMT For receiving or for very low power, 3 watts or so, you could use one of Radio Shack's cable tv antenna switches. Other than that, you will need a heavy duty switch. Most ham antenna switches are 50 ohms so depending on your application you may want to consider that. ESTUDIANTES DE COMUNICACIONES (COMUNICA@mvax1.red.cinvestav.MX) wrote: : Hello everyone. : I wonder if you know about commercial devices that let me switch between : two antennas whose transmition lines are 75 ohms. : Any help would be very appreciated. : Benjamin. : email: bmillan@vader.mixbaal.udg.mx -- Steve Ellington N4LQ@IGLOU.COM Louisville, Ky From lwbyppp@epix.net Thu Mar 07 10:05:20 1996 From: "Anthony R. Gold" Newsgroups: rec.radio.amateur.antenna Subject: Re: switches Date: Wed, 06 Mar 96 10:14:00 GMT Message-ID: <826107240snz@microvst.demon.co.uk> References: <199603052135.NAA26999@UCSD.EDU> Reply-To: tgold@microvst.demon.co.uk In article n4lq@iglou.com "James Casey" writes: > Most ham antenna switches are 50 ohms so depending on > your application you may want to consider that. Except in instrumentation situations, I have never seen a manual coax switch which attempts to maintain constant impedance. Although the connectors on a ham radio coax switch are chosen to mate with 50 ohm coax cable terminations, the switch will work equally well over a wide range of impedances. What are the frequencies, power levels and types of transmission lines involved? Regards, -- Tony - G3SKR / AA2PM email: tgold@panix.com tgold@microvst.demon.co.uk packet: g3skr@n0ary.#nocal.ca.usa.na From lwbyppp@epix.net Thu Mar 07 10:05:22 1996 From: Fromdowntown@eworld.COM Newsgroups: rec.radio.amateur.antenna Subject: TAI-CHI MASTER - 3/13 - PC THEATER Date: 6 Mar 96 15:17:48 GMT Message-ID: <960306071747_26899874@hp1.online.apple.com> ATTENTION FILM-GOERS!: *************************************************** Don't Miss Two of Hong Kong's Most Exciting Stars in One of the Greatest Martial Arts Films of All Time!!! *************************************************** ________________________ | | | THE TAI-CHI MASTER | | | | Directed by Yuen Woo Ping | | Hong Kong, 1993 | | | | Starring: **JET LI** and | | **MICHELLE KHAN** | |________________________| ---------------------------------------- WEDNESDAY, MARCH 13 at the PRICE CENTER THEATER! ---------------------------------------- _________________________ | | | SHOWTIMES: 5:30 / 8:00 / 10:15 | |________________________ | ******************************** GENERAL ADMISSION: $2 TICKETS ON SALE NOW AT THE PRICE CENTER BOX OFFICE ******************************** WIN FABULOUS DOOR PRIZES!!! Enter and WIN the GRAND PRIZE in our TRIVIA RAFFLE!!! From lwbyppp@epix.net Thu Mar 07 10:05:23 1996 From: tomcar@newshost.li.net (Tom Carrubba) Newsgroups: rec.radio.amateur.antenna Subject: Re: Tower Location? Date: 4 Mar 1996 13:59:01 GMT Message-ID: <4hesv5$84g@linet06.li.net> References: <313A4097.7BF@iglou.com> Steve Ellington (n4lq@iglou.com) wrote: : Should I put the beam on the current tower and enjoy the low feedline : loss due to the short distance but suffer whatever effects the house : has on the signal or should I put the new tower out in the middle of : the yard which is 100ft from any surrounding objects and suffer the : effects of feeder loss. The feeder would go from 70ft to 170ft long. : BTW, I plan to use RG-213 coax but am open to suggestions. : Steve N4LQ@iglou.com -- Hi Steve, Put the HF beam on the tower away from the house. This avoid any RFI problems caused by signal<> device overload in your home. The HF beam will also perform better in the clear. My tower (45 ft) is located next to my house and the shack is about 20ft away....I will get RF overload when running full legal power....I have to decrease the power... GL, 73 ============================================================================ Tom Carrubba "To err is human, but to really foul N. Babylon, NY things up requires a computer......" KA2DFO packet radio| ka2dfo@kc2fd.ny.usa.na ============================================================================ From lwbyppp@epix.net Thu Mar 07 10:05:24 1996 From: raiar@inlink.com (Gary V. Deutschmann, Sr.) Newsgroups: rec.radio.amateur.antenna Subject: Re: Tower Location? Date: Tue, 05 Mar 1996 23:08:16 GMT Message-ID: <4hih25$fo3@news1.inlink.com> References: <313A4097.7BF@iglou.com> Steve Ellington wrote: >Here's the deal. My shack is on the end of the house. The tower >is attached to the house at that point. The coax goes straight through >the wall and right up to the antenna. I am preparing to purchase either >tri-band quad or yagi. The tower is 60ft high which makes it about 38ft >above the highest point of the roof. >Recently I came across a good deal on another tower which is 68ft. >My yard covers 2 acres and it's flat,open territory. Here's the >question. >Should I put the beam on the current tower and enjoy the low feedline >loss due to the short distance but suffer whatever effects the house >has on the signal or should I put the new tower out in the middle of >the yard which is 100ft from any surrounding objects and suffer the >effects of feeder loss. The feeder would go from 70ft to 170ft long. >Has anyone got some idea of what a house can do to your signal when >it's directly below the hf beam? >BTW, I plan to use RG-213 coax but am open to suggestions. >Steve N4LQ@iglou.com Just a though, use ladder line between the antenna and the house, then switch to a coax! Actually, the best Tower Location to put your tower is in St. Louis County, just a couple of blocks west of interstate 270 on the North side of the road, set back about 150 feet from the highway :-) That should put it about in the center of my backyard ;-))).... TTUL Gary From lwbyppp@epix.net Thu Mar 07 10:05:25 1996 From: dnorris@k7no.com Newsgroups: rec.radio.amateur.antenna Subject: Re: TRISATO Crankup Tower Info?? Date: Tue, 05 Mar 1996 23:59:40 GMT Message-ID: <4hidej$mjm@news.syspac.com> References: rmccoy@alb.asctmd.com (Russ McCoy) wrote: >I recently acquired a crankup tower from TRISATO. It is 80 feet fully >extended and 20 feet cranked down. I understand that TRISATO was >in the Visalia, CA area, but is no longer in business. I would like to >obtain any information about this tower including a copy of the original >manual if possible: wind loading, recommended guying, capacity, >base configurations, parts availability, anything. >Thanks for any help. >Russ - AA5FP >rmccoy@alb.asctmd.com Tristao sold to U.S. Tower if my recollection is accurate. Contact them for info. They have been more than helpful. Gl/DX cdn C. Dean Norris Amateur Radio Station K7NO e-mail to dnorris@k7no.com From lwbyppp@epix.net Thu Mar 07 10:05:26 1996 From: w8jitom@aol.com (W8JI Tom) Newsgroups: rec.radio.amateur.antenna Subject: Re: Tuner difference: MFJ 989C vs. -986??? Date: 2 Mar 1996 22:30:04 -0500 Message-ID: <4hb3ns$34p@newsbf02.news.aol.com> References: <4hafi4$oh6@newsbf02.news.aol.com> In article <4hafi4$oh6@newsbf02.news.aol.com>, billv21572@aol.com (BillV21572) writes: > >I'd like to know the difference between these two types of tuners. One >(the >986) seems like it would be a simpler operation. Any clear advantage >between >the two from you enlightened types? >tnx es 73 de bill ka9hln They are both T tuners. The differential T gives easier tuning but you're stuck with a pretty high Q on the lower bands, especially 160. The other conventional T allows you to have a little more power capability and lower loss on the low bands. 73 Tom From lwbyppp@epix.net Thu Mar 07 10:05:27 1996 From: Cecil Moore Newsgroups: rec.radio.amateur.antenna Subject: Re: W6KKT VISALIA HF MOBILE ANTENNA "SHOOTOUT" INFO Date: 5 Mar 1996 16:11:56 GMT Message-ID: <4hhp4c$9d3@itnews.sc.intel.com> References: <4hc0ac$leq@ns.kern.com> wrt@eskimo.com (Bill Turner) wrote: >In article <4hc0ac$leq@ns.kern.com>, Jesse Touhey wrote: >>W6KKT Will be conducting another HF Mobile Antenna System "Shootout" at >>the upcoming Visalia, Calif.DX convention. This event will be held at the >>U.S Towers factory, Saturday, April 20th, 10:00am. The test frequency >>will be 3995kc. >Can you provide some details on the testing? I'm interested in how to >compensate for differing feedpoint impedances among other issues. Could you please post the rules? Like height/length limit, etc. thanks and 73, Cecil, KG7BK, OOTC (not speaking for my employer) From lwbyppp@epix.net Thu Mar 07 10:05:28 1996 From: flanders@znet.groupz.net (Jerry Flanders) Newsgroups: rec.radio.amateur.antenna Subject: Re: W6KKT VISALIA HF MOBILE ANTENNA "SHOOTOUT" INFO Date: Tue, 05 Mar 1996 19:16:49 GMT Message-ID: <4hi3us$515@news1.sunbelt.net> References: <4hc0ac$leq@ns.kern.com> wrt@eskimo.com (Bill Turner) wrote: >In article <4hc0ac$leq@ns.kern.com>, Jesse Touhey wrote: >>W6KKT Will be conducting another HF Mobile Antenna System "Shootout" at >>the upcoming Visalia, Calif.DX convention. ... >.....73s...Jesse (W6KKT) >------------------------------------------------------- >Can you provide some details on the testing? I'm interested in how to >compensate for differing feedpoint impedances among other issues. >73, Bill W7LZP ------------------------------------------------------------------------------ ----------------------------------- One of their earlier shootouts (last year's, I think) was written up in QST. They only measured the received field strength in one direction (in line with a front headlight, I think) with the antenna actually mounted on the contestant's vehicle. Jerry W4UKU From lwbyppp@epix.net Thu Mar 07 10:05:29 1996 Newsgroups: rec.radio.amateur.antenna From: pineapp@netcom.com (Daniel Curry) Subject: Re: W6KKT VISALIA HF MOBILE ANTENNA "SHOOTOUT" INFO Message-ID: References: <4hc0ac$leq@ns.kern.com> <4hi3us$515@news1.sunbelt.net> Date: Tue, 5 Mar 1996 22:44:52 GMT Jerry Flanders (flanders@znet.groupz.net) wrote: : wrt@eskimo.com (Bill Turner) wrote: : >In article <4hc0ac$leq@ns.kern.com>, Jesse Touhey wrote : : >>W6KKT Will be conducting another HF Mobile Antenna System "Shootout" at : >>the upcoming Visalia, Calif.DX convention. ... : ---------------------------------------------------------------------------- ------------------------------------- : One of their earlier shootouts (last year's, I think) was written up : in QST. It was written up in World Radio Magazine, I believe Sept 1995 issue. : mounted on the contestant's vehicle. : Jerry W4UKU -- .----------------------------------------------+--------------------------. | INTERNET: pineapp@netcom.com (DC436) | Daniel Curry | | AMPRNET : dan@wb6stw.ampr.org [44.4.20.144] | WB6STW | | AX.25 : wb6stw@n0ary.#NOCAL.CA.USA.NOAM | DoD # 1450 SOHC4 # 136 | '----------------------------------------------+--------------------------' From lwbyppp@epix.net Thu Mar 07 10:05:30 1996 From: rbrown@woodtech.com (Raymond A. Brown) Newsgroups: rec.radio.amateur.antenna Subject: Re: What's your favorite 6mt FM mobile antenna? Date: 2 Mar 1996 21:24:52 GMT Message-ID: <4haeb4$ja9@news.paonline.com> References: <4gu1e8$fqq@newsbf02.news.aol.com> <31363423.6CFF@trw.com> Alan Raskind (alan.raskind@trw.com) wrote: : ZaaX wrote: : > : > I would be interested in hearing from anyone that runs 6 meter FM mobile. : > What : > antenna do you use? What do you like or dislike about it? Would you : > recommend : > your antenna to others? Have you used a Larson or Cushcraft fm antenna? : > Any info on this will be greatly appreciated! : > : > 73 Zack Schindler : > N8FNR : : The latest (and said to be one of the best) mobile antenna is made by a : company called COMTELCO. It is handled by Juns Electronics in Los : Angeles (800)882-1343. (Jun's also has a web site: : http://cyber10.csz.com:80/radio). It has been tested by a number of : die-hard 6M users and they all liked it better than the typical 2M 5/8 : base loaded antenna we usually use. Don't know what the exact details : are, but I will probably get one. The key thing is to get "the 6M : antenna that also resonates on 2M as well". The antenna is supposed to : be somewhere around $30. Hmmm!!! :-) I'll have to keep an eye out for this one, especially if it also rez's on 2m! (smack, drool) _Ray_ KB0STN From lwbyppp@epix.net Thu Mar 07 10:05:31 1996 From: w5gyj@primenet.com (James E. Bromley) Newsgroups: rec.radio.amateur.antenna Subject: Re: What's your favorite 6mt FM mobile antenna? Date: 5 Mar 1996 17:55:01 -0700 Message-ID: References: <4gu1e8$fqq@newsbf02.news.aol.com> <31363423.6CFF@trw.com> <4haeb4$ja9@news.paonline.com> >: > ZaaX wrote: >: > >: > I would be interested in hearing from anyone that runs 6 meter FM mobile. >: > What >: > antenna do you use? What do you like or dislike about it? >: Alan Raskind (alan.raskind@trw.com) wrote: >: >: The latest (and said to be one of the best) mobile antenna is made by a >: company called COMTELCO... The key thing is to get "the 6M >: antenna that also resonates on 2M as well". The antenna is supposed to >: be somewhere around $30. > rbrown@woodtech.com (Raymond A. Brown) writes: > > Hmmm!!! :-) I'll have to keep an eye out for this one, especially if it > also rez's on 2m! (smack, drool) Ahhhh *&$%#*&@!!! You guys are a bunch of wimps! The only antenna worthy of 6-meter FM mobile operation is a full-size Antenna Specialists ball-and-spring type that has been retired from a long career with the California Highway Patrol. Even better, it should be personally autographed by Broderick Crawford. Anything else is CellTel effete. Jim Bromley, W5GYJ Glendale, AZ From lwbyppp@epix.net Thu Mar 07 10:05:32 1996 Newsgroups: rec.radio.amateur.antenna Subject: Why long wire TVI Message-ID: <1d.12113.862@travel.com> From: patrick.walkup@travel.com (Patrick Walkup) Date: Sat, 02 Mar 1996 14:31:00 -0640 Distribution: world Good question, I've been thinking of setting up a longwire myself. The plans are simple 99'4'' to the center of 72 ohm coax 8'10'' to braid. Supposed to give good gain 25 degrees off the long end. With my lot, I can set it up pointing NE at approx 50 degrees magnetic. I picked this orientation hoping to hear good dx from the NE. Maybe I'm being optimistic, but I thought 50 degrees,plus or minus 25 degrees was a good beam heading from St. Louis to Europe. What do you think?? Will a longwire beam at 20'cause excessive TVI?? Finally, just what is the approximate beam heading from St Louis to Europe?? So many questions :) Pat --- ‏ OLX 2.1 TD ‏ --T-A+G-L-I+N-E--+M-E-A+S-U-R+I-N-G+--G-A+U-G-E-- --- * travel.com / TRAVEL ONLINE / ST. LOUIS ONLINE From lwbyppp@epix.net Thu Mar 07 10:05:33 1996 From: Cecil Moore Newsgroups: rec.radio.amateur.antenna Subject: Re: Why long wire TVI Date: Sun, 3 Mar 96 21:18:21 -0500 Message-ID: References: <1d.12113.862@travel.com> Patrick Walkup writes: >So many questions :) Hi Pat, unbalanced antennas have a whole set of problems that balanced antennas don't have. If you have room, a balanced antenna would probably be better. Most people who put up unbalanced horizontal wire antennas are simply unable to put up a balanced one. Unbalanced antennas are a lot more unforgiving than balanced ones. I live on 2 acres and could put up a hellava longwire unbalanced antenna. However, a 102 ft. centerfed dipole satisfies my needs except for 75m DX. 73, Cecil, KG7BK, OOTC From lwbyppp@epix.net Thu Mar 07 10:05:34 1996 From: hamop@aztec.asu.edu (CHARLES J. MICHAELS) Newsgroups: rec.radio.amateur.antenna Subject: Re: Why long wire TVI Date: 5 Mar 1996 13:10:19 GMT Message-ID: <4hhefr$cvb@news.asu.edu> G4wnt said - Last shot about RF in the house is to debunk the fond belief that the outer braid of a coax is somehow a "screen" that will "stop nasty RF from getting out". The braid is actually one half of an unbalanced transmission line! The *only* condition where it will not radiate is if the cable is feeding a load equal to its characteristic impedance. Anything else - and the standing wave currents on the braid will radiate where they are not wanted. This is not true. standing waves in a coax do not cause radiation from the outside of the coax. Except for a very small leakage due to the woven nature of most coax outer conductors, the currents are confined to the inner surface of the otu/// outer conductor by skin effect. In most cases currents on the outside of the outer conductor are due to either those flowing from the connection to the antenna of the outer conductor or due to currents induced in the outer condutor by the antenna . Charlie, W7XC -- From lwbyppp@epix.net Thu Mar 07 10:05:35 1996 From: w8jitom@aol.com (W8JI Tom) Newsgroups: rec.radio.amateur.antenna Subject: Re: Why long wire TVI Date: 6 Mar 1996 08:13:21 -0500 Message-ID: <4hk31h$71l@newsbf02.news.aol.com> References: <4hhefr$cvb@news.asu.edu> In article <4hhefr$cvb@news.asu.edu>, hamop@aztec.asu.edu (CHARLES J. MICHAELS) writes: > > This is not true. standing waves in a coax do not cause radiation >from the outside of the coax. Except for a very small leakage due to the >woven nature of most coax outer conductors, the currents are confined to >the inner surface of the otu/// outer conductor by skin effect. In most >cases currents on the outside of the outer conductor are due to either >those flowing from the connection to the antenna of the outer conductor >or due to currents induced in the outer condutor by the antenna . > > Actually the coax sheild ONLY stops radiation and confines the RF to the inside of the shield when the current in the sheild and center conductor are equal and of opposite phase. ALL shields that are small in terms of the WL work this way.Without equal and opposite currents, they aren't shields at all. Except perhaps right at the very end where a real "ground" may occur. At that point, the sheild can act like an electric field shield. We do that is SWR transformers to prevent capacitive coupling between the line and transformer secondary. Without proper termination of the ends, a shield more than the tiniest fraction of a WL long isn't a shield at all. Shield or not, it will radiate as badly as a bare single wire with the same common mode current. SWR has nothing to do with it, it's a common mode problem. Think about that next time you build a shielded loop, hi. It better be a real small shielded loop. 73 Tom From lwbyppp@epix.net Thu Mar 07 10:05:36 1996 From: sw1gak@polaris.mindport.NET (Spencer Trombly) Newsgroups: rec.radio.amateur.antenna Subject: X beam Date: 5 Mar 96 03:45:18 GMT Message-ID: I have some light weight aluminum antennas (WEBSTER) with fiberglass whips that screw into the end. Total length about 20'. OD of the antenna 1.25". I am thinking about constructing a 30 meter 'X' beam as described in chapter 33 of the 93 handbook. Any comments welcome. 73 Spencer Trombly sw1gak@polaris.mindport.com From lwbyppp@epix.net Thu Mar 07 10:05:37 1996 Newsgroups: rec.radio.amateur.antenna From: Tom Skelton Subject: XMIT/RCVE ant. separation? Message-ID: Reply-To: Tom.Skelton@ColumbiaSC.ATTGIS.COM (skeltt) Date: Tue, 5 Mar 1996 00:42:08 GMT Being extremely pleased with the performance of an 80 meter 1/4 wave sort-of inverted L (more like the letter GAMMA instead of L) I experimented with at the new QTH, I want to go ahead and make a permanent installation and wrist-rocket the top wayyy up in a tree. With this in mind, I also want to install the 300 ft beverage (will probably convert to 2-wire design). I have seen reports of noise coupling between XMITantennas and RCVE antennas, but this apparently wasn't a problem at the old QTH. What is this recommended spacing in wavelengths? Any hard-core experience out there? TNX....73, Tom WB4iUX WB4iUX@AOL.COM or Tom.Skelton@ColumbiaSC.ATTGIS.COM ps: Any CQ ZONE 18, 22, 23, 24, 26 or 40 readers want to make some skeds on 80 before the season ends?? ;-) From lwbyppp@epix.net Thu Mar 07 10:05:38 1996 From: n5zgt@swcp.com (Brian Mileshosky) Newsgroups: rec.radio.amateur.antenna Subject: } SPIDER HF Antenna - NEED INFO { Date: Tue, 05 Mar 1996 21:59:19 GMT Message-ID: <4hih5v$gda@sloth.swcp.com> Reply-To: n5zgt@swcp.com Hello Everybody, I am really thinking into buying a Spider HF mobile antenna. This is the 4 band top-loaded HF antenna. I would like to get the following information regarding this antenna from people wjo have used them. What do you like about the antenna? What DON'T you like about the Spider? Is it a good antenna to use mobile? What about at a home QTH? I'm looking into it primarily for 80 and 40 meters. Is this a good antenna for these bands? Also, any other information would be GREATLY appreciated! Thanks! Best of 73, Brian, N5ZGT... n5zgt@swcp.com ________________________________________________________________________ Boy Scouts of America Amateur Radio J.A.S.M. - Troop 41 N5ZGT Albuquerque, NM Packet: N5ZGT @ KC5IZT.ALBQ.NM.USA.NA Great Southwest Council Internet: n5zgt@swcp.com O.A. Lodge 66 _______________________________________________________________________ From lwbyppp@epix.net Mon Mar 11 07:10:31 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: "floating" the output of a tuner. Date: Sun, 10 Mar 96 17:35:29 GMT Message-ID: <4hv446$lo7@crash.microserve.net> References: <4hsvn5$a51@news.cis.okstate.edu> gcouger@master.ceat.okstate.edu (COUGER GORDON) wrote: >Somewhere I read that a tuner doesn't need a balan for balanced loads >if the tuner was allowed to "float". I purchased a tuner almost >compleatly isolated from the case and enclosure. All that is conected >are the ground side of the coax fittings. > >My plan is to install a plexiglass mount for the coax fittings and >removing the ground from the case and chasis and tying the grounds >from both coax fittings togeather. I will of courese ground the case. > >Has anyone done this before and can anyone offer any insight? > >Please don't turn this in to a religous argument about baluns. OK, but it does help to say three Hail Mary's before using one. :) The concept you're proposing will transform the feedpoint impedance to 50 ohms, but it won't provide the necessary unbalanced-to-balanced conversion. As a result, common-mode current will be present on the feedline, and also on the ground in the shack. You would do just as well to short the feedline and drive the entire system like an end-fed wire. 73, Jack WB3U From lwbyppp@epix.net Mon Mar 11 07:10:32 1996 From: gcouger@master.ceat.okstate.edu (COUGER GORDON) Newsgroups: rec.radio.amateur.antenna Subject: "floating" the output of a tuner. Date: 9 Mar 1996 22:11:49 GMT Message-ID: <4hsvn5$a51@news.cis.okstate.edu> Reply-To: Gordon Couger Somewhere I read that a tuner doesn't need a balan for balanced loads if the tuner was allowed to "float". I purchased a tuner almost compleatly isolated from the case and enclosure. All that is conected are the ground side of the coax fittings. My plan is to install a plexiglass mount for the coax fittings and removing the ground from the case and chasis and tying the grounds from both coax fittings togeather. I will of courese ground the case. Has anyone done this before and can anyone offer any insight? Please don't turn this in to a religous argument about baluns. Thanks Gordon AB5DG Gordon Couger Biosystems & Agricultural Engineering. 114 AG Hall Stillwater, OK 74075 gcouger@master.ceat.okstate.edu 405 625-2855 evenings From lwbyppp@epix.net Mon Mar 11 07:10:33 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: "floating" the output of a tuner. Date: Mon, 11 Mar 96 05:41:53 GMT Message-ID: <4i0ema$t59@crash.microserve.net> References: <4hsvn5$a51@news.cis.okstate.edu> <1996Mar10.223737.7115@ke4zv.atl.ga.us> gary@ke4zv.atl.ga.us (Gary Coffman) wrote: >and in the other case, both lines need to be symmetric >with respect to "ground". Isn't that true only when a balun is used at the input or output of the tuner, as in your example? If the feedline currents are isolated from ground (as in a link-coupled tuner), does it matter whether the line is symmetrical to that reference? 73, Jack WB3U From lwbyppp@epix.net Mon Mar 11 07:10:34 1996 Newsgroups: rec.radio.amateur.antenna From: dgf@netcom.com (David Feldman) Subject: 10M duck ant question Message-ID: Date: Sun, 10 Mar 1996 20:44:13 GMT I'm looking for a source for a 10M flexible rubber antenna for a SSB 10M handheld. I tried getting one from Radio Shack that they sell for their CB HT to cut it down a bit, but they never delivered on the special order. I know this kind of antenna won't be efficient, but I am looking for one just the same. 73 Dave WB0GAZ dgf@netcom.com From lwbyppp@epix.net Mon Mar 11 07:10:35 1996 From: w8jitom@aol.com (W8JI Tom) Newsgroups: rec.radio.amateur.antenna Subject: Re: 4:1 or 9:1, which is better? Date: 8 Mar 1996 01:59:11 -0500 Message-ID: <4holrv$rct@newsbf02.news.aol.com> References: <4hnmcb$bfm@ornews.intel.com> In article <4hnmcb$bfm@ornews.intel.com>, Cecil Moore writes: > >4:1 baluns are easy to build or buy and work as well as 9:1. > >73, Cecil, KG7BK, OOTC (not speaking for our employer) > > Hi Tom and Cecil, Cecil forgot to mention 1:1 choke baluns work better than 4:1 baluns when the load is not the design impedance of the balun!!!!! I would guess most books recommend 4:1 because the author hasn't really thought about the problem. ;-) 73 Tom From lwbyppp@epix.net Mon Mar 11 07:10:36 1996 From: benjamin@ele.tut.fi (Gr|nlund Pentti) Newsgroups: rec.radio.amateur.antenna Subject: Re: Alarm decal antenna. Date: 07 Mar 1996 23:20:41 +0200 Distribution: world Message-ID: References: <4gv3hm$oou@oldsuna.gmr.com> <4h0o44$s5q@hgea01.hgea.org> dstuben@rcsuna.gmr.com (David Stuben) wrote: >I would like to know if anyone is using the patch type antenna that was >advertised in QST some months ago. This antenna is disguised as a alarm >decal, and is for the 2m band. I am interested in this type of an antenna fo r >a new truck that I have on order. I have a glass mount antenna now, but the >performance is somewhat marginal. A quarter wave magmount works better! I >could just drill a hole in the roof, but something inside seems neat too. >Also any information on loop type antennas for 2m/440, such as feeding, >mounting,etc would be great. Thanks!! And Wayne, NH6GJ, continues: If you think the glass mount is marginal, then the patch antenna will be much worse. I can normally reach the Diamond Head repeater with a 1/4 wave or a glass mount Larson Dual Band antenna from my driveway, a distance of about 28 miles (probably more like 25 as the crow flies), but couldn't bring it up with the patch antenna when I tried it a few years ago. They may have improved them, but I doubt it. The size (capture area) just seems too small. On 2 meters, anything inside a car is easily 10 dB or more worse than a similar setup outside. The windows are quite small comp- ared to the wavelength. 70 cm is easier, AMPS/TACS/NMT900/GSM or 23 cm even more... Benjamin OH3BK -- Pentti "Benjamin" Gronlund benjamin@ele.tut.fi Life member of IAAA, the International Association for Adjustment Aces *** Original Live Reports from the Taxman's Paradise *** From lwbyppp@epix.net Mon Mar 11 07:10:37 1996 From: Cecil Moore Newsgroups: rec.radio.amateur.antenna Subject: Re: Am I wasting my time looking for a 5/8 2m/70cm mobil antenna Date: 7 Mar 1996 16:04:55 GMT Message-ID: <4hn1f7$im5@itnews.sc.intel.com> References: <4hn02t$51q@acmez.gatech.edu> soniat@prism.gatech.edu (Edward Soniat du Fossat Jr) wrote: > >I am looking for a 2M/70cm dual band mobile that is 5/8 in BOTH 2m and 70cm. You can't find one because an antenna that is 5/8 on 2m might as well be made better than a 5/8 on 70cm. Comet and Diamond make antennas that have the gain of a 5/8 on 2m and more gain than a 5/8 on 70cm. 73, Cecil, KG7BK, OOTC (not speaking for my employer) From lwbyppp@epix.net Mon Mar 11 07:10:38 1996 From: jimf@zoinks.corp.sgi.com (Jim Fellows) Newsgroups: sci.astro.amateur,rec.radio.amateur.space,rec.radio.amateur.misc,rec.radio.amateur.homebrew,rec.radio.amateur.equipment,rec.radio.amateur.antenna,misc.invest.technical,misc.invest.stocks,misc.invest.funds,misc.invest.canada Subject: Re: Announsing: Technology Patent Available For Purchase Date: 4 Mar 1996 22:30:15 GMT Message-ID: <4hfqtn$6kb@murrow.corp.sgi.com> References: <4hdlvj$kvv@sun.sirius.com> To: gherbst@msn.com In article , gherbst@msn.com writes: |> Paul, |> |> That's a very blatent claim you make. This patent went through with only |> one need for clarification from the PTO. Obviously know one else sought |> such a patent which is evidence by the PTO issuing me patent # 5457342. |> |> Those companies you mention have devices that are similar with respect to |> cooling only if you care to follow the patents mentioned on my abstract. |> However, NONE have developed the device I have NOR do they have a patent |> on such a device. As such, I am the sole owner to pursue development of |> this product or companies under infringement. |> |> Gaerhardt G. Herbst |> What I am wondering is what this has anything to do with amateur radio antenna s, homebrew, space, etc.? The point is that this, and the preceding posts were made to the amateur radio news groups. Cooling of microprocessors, and your grandstanding of being awarded a patent a re of no interest to me or in any way pertinent to my interest in amateur radio. And that is why the newsgroup(s) have those titles. If you are looking for invetors, get a clue and do it somewhere else. If you are simply so proud of yourself for being awarded a patent for what appears to be anothers work, then HIP HIP HOORAY for you! Now grow up and go away. Jim From lwbyppp@epix.net Mon Mar 11 07:10:39 1996 From: paul@laughton.com (Paul Laughton) Newsgroups: sci.astro.amateur,rec.radio.amateur.space,rec.radio.amateur.misc,rec.radio.amateur.homebrew,rec.radio.amateur.equipment,rec.radio.amateur.antenna,misc.invest.technical,misc.invest.stocks,misc.invest.funds,misc.invest.canada Subject: Re: Announsing: Technology Patent Available For Purchase Date: Tue, 05 Mar 1996 06:50:20 GMT Message-ID: <4hgo64$o5n@sun.sirius.com> References: <4hdlvj$kvv@sun.sirius.com> Reply-To: paul@laughton.com gherbst@msn.com wrote: >Paul, >That's a very blatent claim you make. This patent went through with only >one need for clarification from the PTO. Obviously know one else sought >such a patent which is evidence by the PTO issuing me patent # 5457342. >Those companies you mention have devices that are similar with respect to >cooling only if you care to follow the patents mentioned on my abstract. >However, NONE have developed the device I have NOR do they have a patent >on such a device. As such, I am the sole owner to pursue development of >this product or companies under infringement. >Gaerhardt G. Herbst I am sorry if my statement upset you. It is just that I have seen so many patents issued for which there is substantial prior art. Usually, no one bothers to dispute these patents unless the patent holder attempts to assert his or her 'rights.' Then it is a matter of who has the most bucks to give to lawyers. The only people that really win in these case are the lawyers. I really do not know the details of your patent and what your claims are. I just know that cooling of IC's has been used for many years to stabilize ICs against environemental changes. Besides IBM, Amdahl, etc, there are numerous military applications of the technique. Closer to home, in the world of CCD imaging we have had TE cooled and requlated ICs for many years. The cooling of CCDs is used 1) to lower the thermoelectic noise and 2) keep the noise (a function of temperature) at a constant value (via feedback regulation). The fact that no one else has attempted to patent this idea is probably due to fact of its total lack of novelty. On the other hand, since I can not imagine what you did come up with that is novel in this arena, maybe you really do have something that is unique and of value. In any case, good luck. -Paul From lwbyppp@epix.net Mon Mar 11 07:10:41 1996 From: jfsawyer@freewave.com (Jonathan sawyer) Newsgroups: sci.astro.amateur,rec.radio.amateur.space,rec.radio.amateur.misc,rec.radio.amateur.homebrew,rec.radio.amateur.equipment,rec.radio.amateur.antenna,misc.invest.technical,misc.invest.stocks,misc.invest.funds,misc.invest.canada Subject: Re: Announsing: Technology Patent Available For Purchase Date: Thu, 07 Mar 96 04:16:53 GMT Distribution: world Message-ID: <4hlv15$18f@news-2.csn.net> References: <4hg97g$fef@cloner3.netcom.com> gherbst@msn.com wrote: > >> Correct you Charles. >> >> Gerhardt G. Herbst >> >Whoops...I mean correct you are Charles... > >Gerhardt > In 1982 I put a Peltier Cooler on a 8087 coprocessor in an IBM computer in an effort to speed up the clock. I had a PC board made and along with schematics and documentation. This progressed into modules for 80287's. In fact I hold the record for the highest speed attained using a 80287 in an IBM AT computer by cooling the 80287 down to -50 deg C. I therefore have prior documented art on this invention and demand all royatie s should be sent to me. Jonathan Sawyer FreeWave Technolgies From lwbyppp@epix.net Mon Mar 11 07:10:42 1996 From: paul@laughton.com (Paul Laughton) Newsgroups: sci.astro.amateur,rec.radio.amateur.space,rec.radio.amateur.misc,rec.radio.amateur.homebrew,rec.radio.amateur.equipment,rec.radio.amateur.antenna,misc.invest.technical,misc.invest.stocks,misc.invest.funds,misc.invest.canada Subject: Re: Announsing: Technology Patent Available For Purchase Date: Mon, 04 Mar 1996 02:54:14 GMT Message-ID: <4hdlvj$kvv@sun.sirius.com> References: Reply-To: paul@laughton.com gherbst@msn.com wrote: >Gerhardt G. Herbst II, is the patent holder for "Cold Spot Module". >This product is for sale to an individual or manufacturer. >The "Cold Spot Module" is used to effectively reduce the operating >temperature of integrated circuits such as computer CPUs to maintain >reliability under extreme operating conditions. This module is protected >under a U.S. Utility Patent issued in October of 1995. A Utility patent >provides the strongest protection under U.S. law. >An independent North American Market Study was done on the product and the >potential market has been identified. >The product has not yet been introduced to the general public but is referenc ed >in the U.S. Patent catalog which is posted periodically. For an on-line refer ence >refer to: >http://www.uspto.gov >Search on Patent Number: 5457342 >The title abstract is: Integrated circuit cooling apparatus >Note: A search on just the patent number will bring up the details. >Exclusive rights can be purchased reasonably with negotiable license term. >For further information, contact Gerhardt G. Herbst II. > Gerhardt G. Herbst II > 133 Wynstay > Valley Park, MO 63088 > Phone: (314) 861-0426 > E-mail: gherbst@msn.com I wonder how Mr Herbst slipped this one past the prior art investigation? This technology has been around since the early 70's - at least. For example, IBM and Amdahl main frames made extensive use of it. From lwbyppp@epix.net Mon Mar 11 07:10:43 1996 From: cjtutt@ix.netcom.com(Charles Tutt ) Newsgroups: sci.astro.amateur,rec.radio.amateur.space,rec.radio.amateur.misc,rec.radio.amateur.homebrew,rec.radio.amateur.equipment,rec.radio.amateur.antenna,misc.invest.technical,misc.invest.stocks,misc.invest.funds,misc.invest.canada Subject: Re: Announsing: Technology Patent Available For Purchase Date: 5 Mar 1996 02:34:24 GMT Message-ID: <4hg97g$fef@cloner3.netcom.com> References: In gherbst@msn.com writes: > >Paul, > >That's a very blatent claim you make. This patent went through with only >one need for clarification from the PTO. Obviously know one else sought >such a patent which is evidence by the PTO issuing me patent # 5457342. > >Those companies you mention have devices that are similar with respect to >cooling only if you care to follow the patents mentioned on my abstract. >However, NONE have developed the device I have NOR do they have a patent >on such a device. As such, I am the sole owner to pursue development of >this product or companies under infringement. > >Gaerhardt G. Herbst > I believe your final statement is too broad. You may "preclude others from practicing your invention" is closer to the correct formulation. From lwbyppp@epix.net Mon Mar 11 07:10:45 1996 Newsgroups: sci.astro.amateur,rec.radio.amateur.space,rec.radio.amateur.misc,rec.radio.amateur.homebrew,rec.radio.amateur.equipment,rec.radio.amateur.antenna,misc.invest.technical,misc.invest.stocks,misc.invest.funds,misc.invest.canada Subject: Re: Announsing: Technology Patent Available For Purchase Message-ID: From: frederick.mckenzie-1@kmail.ksc.nasa.gov (Fred McKenzie) Date: Thu, 07 Mar 1996 17:29:01 -0500 References: In article , gherbst@msn.com wrote: > That's a very blatent claim you make. This patent went through with only > one need for clarification from the PTO. Obviously know one else sought > such a patent which is evidence by the PTO issuing me patent # 5457342. Gaerhardt- I think some of us have jumped to the erroneous conclusion that your invention duplicates prior art. On the other hand, your statements do not clearly show how it is different from prior art. You are looking for investors to finance development of a product that on the surface, appears to be old technology. I suggest you revise your "sales pitch", so that it is clear that your invention is (a) new, and (b) of commercial value. In other words, why would one want to use your invention instead of existing spot-cooling techniques? 73, Fred, K4DII From lwbyppp@epix.net Mon Mar 11 07:10:46 1996 From: graham@southlin.demon.co.uk (Graham Seale) Newsgroups: rec.radio.amateur.antenna Subject: Re: Antenna arcing Date: Thu, 07 Mar 1996 00:55:28 GMT Distribution: world Message-ID: <19960307.005528.27@southlin.demon.co.uk> References: <4hhelc$d2f@news.asu.edu> Reply-To: graham@southlin.demon.co.uk In message <4hhelc$d2f@news.asu.edu> CHARLES J. MICHAELS wrote: > > Always provide a DC path to ground so that charge is leaked off as > fast as it accumulates and it then does not get to sufficient voltage > to arc anywhere. > > Charlie, W7XC Hi Charlie I dont know who started this thread, but I should like to append to yours if I may. The one time I heard a flashover from mine, I shorted and grounded the connector. This grounding "switched on" a dim violet discharge from the insulator up in the tree at the end of the dipole. Call me paranoid, but I feared a strike, so I undid the halyards and lowered the whole antenna onto the ground. Since then I have seen an article in RadCom describing a homebrew foil-leaf electroscope made up from an empty Nescafe jar and a bolt fitted into the plastic lid. One end of the thin strip of foil is taped to the bolt such that it hangs against it, and will deflect from the bolt if it gets charged. This jar is used as a "charge monitor" if hooked to antenna line via a piece of coax inner (dielectric makes good insulation!). I have also seen a scheme where a dipole is "grounded" via 15K 20W resistors sealed in plastic tubing, and mounted at the feedpoint. These have spark gaps going around them, made of dipole wire filed sharp and set nearly touching. Final trick is to file *very* sharp points onto the dipole ends at the insulators. The rationale here is the corona "starts" at a much lower voltage difference, and quietly discharges all the local fields, making it more likely a strike will have to happen elsewhere. The antenna is held at near ground potential by the resistor connection. I don't know if the above notion represents credible physics, but I can do without being on the end of sharp pointy things squirting billions of ions into a corona right under a thundercloud! If there are any experts on lightning in this group - then do tell. This is a subject where real knowledge seems a bit sparse. 73s G4WNT -- Graham Seale From lwbyppp@epix.net Mon Mar 11 07:10:47 1996 From: hamop@aztec.asu.edu (CHARLES J. MICHAELS) Newsgroups: rec.radio.amateur.antenna Subject: Re: Antenna arcing Date: 8 Mar 1996 04:51:33 GMT Message-ID: <4hoecl$72h@news.asu.edu> I think it unwise to try to measure the magnitude of the charge before thinking of disconnecting the feedline outside the house and grounding it. I also think it unwise to encourage start or /// of a carona discharge since it may be the start of a strike that would otherwise occur some where else. The discharge need not be made fast in my experience since long ago before I took the precaution I found that the arc time constant of build up to arc over was usually a t least a few seconds and it doesn't take a very fast (i.e. low resitance to ground ) to keep up with it. Charlie, W7XC -- From lwbyppp@epix.net Mon Mar 11 07:10:47 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: antenna efficiency Date: Thu, 07 Mar 96 14:35:49 GMT Message-ID: <4hmseh$o67@crash.microserve.net> References: <4ha20h$eff@chnews.ch.intel.com> <4hid61$1as@usenet.continental.com> <4hkcs4$t3u@itnews.sc.intel.com> <4hmljj$10j@ionews.ionet.net> Hank Blackstock wrote: >Another way to solve that problem is to use a Johnson Matchbox >tuner instead of the Mickey Mouse tuners that are manufactured >today. Some of the new tuners seem to be pretty good. Buying one with a balun is sure a waste of money though. :) 73, Jack WB3U From lwbyppp@epix.net Mon Mar 11 07:10:48 1996 From: Rolfe Tessem Newsgroups: rec.radio.amateur.antenna Subject: Re: antenna efficiency Date: Thu, 07 Mar 1996 11:56:22 -0500 Message-ID: <313F1536.695C@ldp.com> References: <4hmseh$o67@crash.microserve.net> <4hmuql$7j9@newsbf02.news.aol.com> W8JI Tom wrote: > It's pretty easy to imply that the tuners are built poorly, but who would > pay a couple of grand or more to buy a new tuner like the old Matchbox? > > A modified reversible L network; with no cabinet shielding, no balun and > no warranty (using a little 12 or 14 gauge coil) costs a thousand bucks! > > Products are market driven, and most applications are filled nicely by > todays 300 to 400 dollar tuners. that's why they're built the way they > are. Tom, What is it about the Johnson Matchbox that makes you think they'd be so expensive if they were manufactured to the same specs today? I have one, and while I like it, I don't think there's anything inside that is significantly more heavy-duty than the best of the currently-available tuners. Rolfe W3VH -- Rolfe Tessem | Lucky Duck Productions, Inc. rolfe@ldp.com | 96 Morton Street (212) 463-0029 | New York, NY 10014 From lwbyppp@epix.net Mon Mar 11 07:10:49 1996 From: Cecil Moore Newsgroups: rec.radio.amateur.antenna Subject: Re: antenna efficiency Date: 6 Mar 1996 16:01:08 GMT Message-ID: <4hkcs4$t3u@itnews.sc.intel.com> References: <4ha20h$eff@chnews.ch.intel.com> <4hid61$1as@usenet.continental.com> "Paul Christensen, N9AZ" wrote: >>The moral is that a non-resonant antenna length can be >>made to resonate and radiate just as efficiently as a >>resonant antenna length. > >George Grammer himself could't have done a finer job in making this >point. Thanks Paul, IMO almost all the loss problems associated with non- resonant length ladder-line fed dipoles are in the network that matches the balanced line to the unbalanced transmitter. I have solved those problems and the results are almost unbelievable. My tuner uses one parallel variable capacitor plus some toroids. 73, Cecil, KG7BK, OOTC (not speaking for my employer) From lwbyppp@epix.net Mon Mar 11 07:10:51 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: antenna efficiency Date: Sun, 10 Mar 96 18:47:45 GMT Message-ID: <4hv8bn$lo7@crash.microserve.net> References: <4hmseh$o67@crash.microserve.net> <4hmuql$7j9@newsbf02.news.aol.com> <313F1536.695C@ldp.com> Rolfe Tessem wrote: >Tom, > >What is it about the Johnson Matchbox that makes you think they'd be >so expensive if they were manufactured to the same specs today? I >have one, and while I like it, I don't think there's anything inside >that is significantly more heavy-duty than the best of the >currently-available tuners. > >Rolfe W3VH I've been slowly collecting parts to build a 160-10M version of the KW Match Box. A few of the reasons for the expense Tom refers to are: 1. The output coil in a link tuner needs to be approximately two to three times the value of the coil in a T network. This means the coil must be much larger while still maintaining good Q. 2. The switching in a link tuner is more complex than a T network. For one thing, switching of the output coil requires a well-isolated, two-deck RF switch. This switch must have a much higher voltage rating than the switch in a T network, which usually has the common contact tied to ground. The cost of this switch, plus the coil assembly, is more than the cost of even a good roller inductor. In order to cover 160M through 10M, it may also be necessary to use additional switch decks to add more capacitance on 160M. The alternative would be larger variable capacitors with vernier drives, but the necessary capacitors would be outrageously expensive. Also, the tuner would probably approach the size of a small block V8. Coverage down to 160M will require that the input link be switched as well, and this represents another not-insignificant cost. 3. In order to minimize stray capacitance and optimize balance, the link tuner should have as few connections to the output coil as possible. This means that rather than being tapped helter-skelter at as many places as possible, the taps should be placed only where they're needed, on a band-by-band basis. Considerable engineering time is required to establish the proper location of these taps. 4. For best balance, the link tuner requires two series variable capacitors. They must be isolated from each other and from ground, but must be capable of being rotated as a single unit. The tuner also requires at least a third variable capacitor in parallel with the output coil. If the design calls for this capacitor to be split, with the center grounded (as in the Match Box), then each section must have twice the capacitance of a single unit. All of this is more complex and costly than a T network tuner. 5. The capacitor plate spacing in my KW Match Box is much larger than the capacitors in my mid-70's Dentron 3KW tuner, and the Dentron was not a cheap tuner in its day. I've also heard that current 3KW tuners from MFJ use spacing that's smaller than the 275W Match Box. I know MFJ doesn't make the most expensive tuners on the market, but are you sure your statement comparing the Johnson parts to others is accurate? I can only remember a few times in 30 years that I've seen capacitors this large, and those were in (or removed from) commercial equipment. I also want to say that the interest in balanced tuners has made me think about going into production. I've examined methods of manufacturing the switches, the coils and the capacitors that would save cost over the purchase of commercially-available components. However, when one adds the cost of these components to the chassis, paint and silkscreening, engineering time, production time, and advertising and marketing, it's a *major* loss for anything less than $1,000 each. To illustrate this more directly, the KW Match Box could be purchased at one time with the directional coupler and meter for about $150.00. That year, new fuel-injected Corvettes were selling for less than $4,000.00. The ratio of the "then" and "now" cost of the car is about 9:1, and if you apply that to the Match Box, it should sell for $1,350 in today's economy. Even at that, you'd still have to update its frequency coverage with the addition of larger and more costly parts. 73, Jack WB3U From lwbyppp@epix.net Mon Mar 11 07:10:52 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: Antenna for apartment Date: Thu, 07 Mar 96 14:51:00 GMT Message-ID: <4hmtb0$o67@crash.microserve.net> References: <4hicb8$msv@bolivia.it.earthlink.net> kb6ojs@earthlink.net (Steve Silverwood) wrote: >Here's the situation: > >I live in a downstairs apartment with a small backyard. >Being a Tech Plus licensee, I will probably want to go for 40m CW >operation. I've considered the Butternut bowtie beam antenna, but >not sure about how it will perform in the above environment. Seems to me your two biggest problems will be A) finding an antenna that is both efficient and unobtrusive, and B) TVI/RFI. The first could be solved reasonably well with a shortened dipole made from magnet wire and fed with TV twinlead. If this was driven by a 275 watt Johnson Matchbox (and if the run of line was reasonably short), you could have a pretty efficient system. The severity of the second problem depends in large part on whether your neighbors already know that you're a ham. Other than that, TVI will be minimized by using a low pass filter at the output of the rig. TVI and RFI will both be minimized by using a balanced antenna that doesn't rely on earth ground to prevent unwanted radiation from other parts of the system. 73, Jack WB3U From lwbyppp@epix.net Mon Mar 11 07:10:53 1996 Newsgroups: rec.radio.amateur.antenna From: choffman@pelican.davlin.net (Charles Hoffman) Subject: Re: Antennas in PVC pipe Message-ID: Date: Thu, 7 Mar 1996 20:58:22 GMT Reply-To: choffman @pelican.davlin.net References: <3573@NJ7P> <4hjilt$atm@zdi.informatik.uni-stuttgart.de> Would not suggest using pvc for all above mentioned reasons; better choice might be Delrin (tm) or Lexan(tm) plastic tubes...much better. 73 K5SBU gelleric@kafka.informatik.uni-stuttgart.de (Wolfgang Gellerich) wrote: >In article <3573@NJ7P>, n7oo@azgate.nj7p.ampr.ORG (Jack Taylor) writes: >|> Today started to assemble a J-pole antenna for 224 MHz. Used number >|> 12 solid wire and planned on enclosing it inside a length of 1 in dia >|> PVC pipe. Using a grid dip meter, cut the antenna to resonate on 224. >|> >|> However upon inserting it inside the pipe, the resonant frequency dipped >|> about 8 MHz lower! Went ahead and trimmed it some more until resonance >|> inside the pipe was reached at 224 MHz. In this case at least, looks >|> like PVC affects the VF of the physical dimensions by 0.91 as compared >|> to free space. >|> >|> Has anyone else on the group have experience with placing an antenna >|> inside of PVC pipe? >|> >As far as I know, the PVC molecules can become "activated" by certain >frequencies, and PVC is generally not considered to be a good choice >as material to construct antennas from. >73s, Wolfgang DJ3TZ From lwbyppp@epix.net Mon Mar 11 07:10:54 1996 From: ranecurl@engin.umich.edu (Rane Curl) Newsgroups: rec.radio.amateur.antenna Subject: Re: Antennas in PVC pipe Date: 7 Mar 1996 17:27:21 GMT Message-ID: <4hn69p$b13@srvr1.engin.umich.edu> References: <3573@NJ7P> <4hjilt$atm@zdi.informatik.uni-stuttgart.de> <4hn62g$avm@srvr1.engin.umich.edu> In article <4hn62g$avm@srvr1.engin.umich.edu>, Rane Curl wrote: >(vacuum is 1.0), so the capacitance is increased, and the resonant >frequency is lowered - by a *factor* of 4.3, in fact, if we lived in a By a *factor* of SQRT(4.3) - sorry about that. Should think first... Rane N8REG From lwbyppp@epix.net Mon Mar 11 07:10:55 1996 From: Alan Doherty Newsgroups: rec.radio.amateur.antenna Subject: Re: Antennas in PVC pipe Date: Tue, 5 Mar 1996 14:58:01 +0000 Distribution: world Message-ID: <7jpBDAA5ZFPxEwwe@gi0otc.demon.co.uk> References: <3573@NJ7P> In article <3573@NJ7P>, Jack Taylor writes >Today started to assemble a J-pole antenna for 224 MHz. Used number >12 solid wire and planned on enclosing it inside a length of 1 in dia >PVC pipe. Using a grid dip meter, cut the antenna to resonate on 224. > >However upon inserting it inside the pipe, the resonant frequency dipped >about 8 MHz lower! Went ahead and trimmed it some more until resonance >inside the pipe was reached at 224 MHz. In this case at least, looks >like PVC affects the VF of the physical dimensions by 0.91 as compared >to free space. > >Has anyone else on the group have experience with placing an antenna >inside of PVC pipe? > >73 de Jack > Hi Jack, I have made various J-Pole and Slim Jim type antennas inserted in PVC water pipe. One thing to be aware of is the properties of some plastic materials change in sunlight. I had this problem occur with one antenna fitted to a boat, after a few years I noticed the SWR had gone up quite a bit. Thinking salt water had got in, I stripped the antenna down. But it was as clean as the day it was made, so I checked the SWR outside the PVC pipe and it was OK. But it shot up again when placed into the pipe. Make sure the PVC you use is UV stabilized. Good luck, and have fun. 73's +++++++++++++++++++++++++++++++++++++++ + Happiness IS Amateur Radio + + Alan Doherty, GI0OTC + + E-Mail: alan@gi0otc.demon.co.uk + + ****** + +++++++++++++++++++++++++++++++++++++++ From lwbyppp@epix.net Mon Mar 11 07:10:57 1996 From: AC6V Newsgroups: rec.radio.amateur.antenna Subject: Re: Antennas in PVC pipe Date: 5 Mar 1996 15:08:00 GMT Message-ID: <4hhlcg$8h3@reader2.ix.netcom.com> References: <3573@NJ7P> To: n7oo@azgate.nj7p.ampr.ORG Hi Jack, A QSO on the repeater here involved a similar situation for an HF antenna in PVC pipe. The builder sed that the PVC he used had a lot of carbon in it. He changed the type of PVC and solved the problem. Check the supplier of your PVC for composition. This is unverified by me but maybe worth checking on. 73 Rod -- ***************************************************************** Hark! I Have Hurled My Words To The Far Reaches Of The Earth! What King Of Old Could Do Thus ? --- AC6V ***************************************************************** A Man May Know Of The World Without Leaving The Shelter Of His Own Home! Loa-Tsze ***************************************************************** From lwbyppp@epix.net Mon Mar 11 07:10:57 1996 From: jimf@zoinks.corp.sgi.com (Jim Fellows) Newsgroups: rec.radio.amateur.antenna Subject: Re: Antennas in PVC pipe Date: 7 Mar 1996 22:59:48 GMT Message-ID: <4hnpp4$e15@murrow.corp.sgi.com> References: <3573@NJ7P> <4hjilt$atm@zdi.informatik.uni-stuttgart.de> Well, I remember this thread from just a month ago, but don't remember the res ults. My question is, what about other "plumbing" materials for supports. Such as a boom for a 435 helix or yagi made of ABS. Elements not inside suppo rt. I'm not sure about the correctness of the microwave test method, and know of n o other way of testing. Jim From lwbyppp@epix.net Mon Mar 11 07:10:58 1996 From: hamop@aztec.asu.edu (CHARLES J. MICHAELS) Newsgroups: rec.radio.amateur.antenna Subject: Re: Antennas in PVC pipe Date: 9 Mar 1996 20:02:13 GMT Message-ID: <4hso45$im1@news.asu.edu> Jack said - I've never used PVC pipe over an antenna, but I know the insolated wire does make a big differance. I thought I'd be smart and I substuted a lenght of #12 PVC insolated house wire for the stainless steel whip on a 2 meter mobile antenna, as it would be easer to trim to frequecy, and I would then just transfer the lenght to the steel whip. I did that and recheck the SWR and it was 4 to 1. It turned out that it was about 3 in too short and I had to buy a new steel whip and do it over. It was a good (?) example of dielectric loading. This happens at all frequencies, but is more noticable at higher frequencies. John Passaneau, WB8EIY, State College, Pa. Jack, Was the diameter of the whip the same as that of the #12 wire? The diameter also influences the resonant frequency. Charlie, W7XC -- From lwbyppp@epix.net Mon Mar 11 07:10:59 1996 From: zut@cais.com Newsgroups: rec.radio.amateur.antenna Subject: AR-22 Rotator Limit Date: Sat, 9 Mar 1996 18:15:26 EST Message-ID: Can anyone tell me what the maximum rating (square feet) is for a CDR AR-22 rotator with the antenna mounted at zero height above the rotator? Thanks, Tony Stalls, K4KYO zut@cais.com From lwbyppp@epix.net Mon Mar 11 07:11:00 1996 From: pruth@ocvaxa.cc.oberlin.edu Newsgroups: rec.radio.amateur.antenna Subject: Best tall dual band vertical? Date: 7 Mar 1996 14:20:27 GMT Message-ID: <4hmrbb$if6@news.cc.oberlin.edu> Reply-To: pruth@ocvaxa.cc.oberlin.edu Having taken down a Valor Pro-Am 555 16.5-foot dual band vertical due to skyrocketing SWR and finding lots of moisture in the base as well as pieces of loose metal in the radome, I'd like to replace it with a similar antenna but one which will survive northern Ohio wind and moisture better than the 555. Thank you for your suggestions. --Bill KB8USZ pruth@alpha.cc.oberlin.edu From lwbyppp@epix.net Mon Mar 11 07:11:01 1996 From: jhill@minn.net (John Hill) Newsgroups: rec.radio.amateur.antenna Subject: Re: Best way to insall a Rohn HBX tower Date: Thu, 07 Mar 96 02:26:48 GMT Message-ID: <4hlhhn$h45@cobra.Minn.Net> References: <4hia6a$10bc@chnews.ch.intel.com> In article <4hia6a$10bc@chnews.ch.intel.com>, tom_boza@ccm.ch.intel.com (WB7ASR) wrote: >I purchased a Rohn HBDX-40 self-supporting tower with the three >four foot long concrete base leg L-stubs. After I dig my base hole >and install the rebar, what is the best way to install the three tower >base leg L-stubs into the hole before the concrete is poored to insure >they will be level and ture once the concrete has been poured? Tom, what I did was attach the stubs to the first tower section. I then places my 2x6 forms around the edge of the hole. Then, I place two lengths of 2x4 across the forms in a cross pattern. I straddled the cross with the bottom section with the three stubs dangling in the hole. (make sue the dont touch the rebar). I placed attached 3 pieces of rope to the section about 7 feet up from the bottom and anchored them with stakes about 10 feet from it, one per side. Each length of rope was a double run. Imagine them as 3 guys, one per side. I placed a short dowell in each doubled run and placed a level against the parallel part of the section sides. By alternately tightening the 3 rope "guys", in a tourniquet manner, I got to a point where the sides of the section were all perpendicular and reasonable tension was placed on the 3 "guys". This prevents the section from moving when the concrete hits it going into the hole. My HBX 56 has been up for 11 years with my TH5 on it and is still perpendicular. Good Luck. John, NJ0M John S. Hill, NJ0M Product Engineer Timewave Technology jhill@minn.net From lwbyppp@epix.net Mon Mar 11 07:11:02 1996 From: Robert Bissett Newsgroups: rec.radio.amateur.antenna Subject: Re: Best way to insall a Rohn HBX tower Date: Thu, 07 Mar 1996 13:36:48 -0500 Message-ID: <313F2CC0.C71@monmouth.com> References: <4hia6a$10bc@chnews.ch.intel.com> To: WB7ASR WB7ASR wrote: > > I purchased a Rohn HBDX-40 self-supporting tower with the three > four foot long concrete base leg L-stubs. After I dig my base hole > and install the rebar, what is the best way to install the three tower > base leg L-stubs into the hole before the concrete is poored to insure > they will be level and ture once the concrete has been poured? I helped a friend install one of these recently. Attach the stubs to the bottom section of the tower. Get three friends with vertical levels. On pouring day prop the legs in the center of the hole with one man on each leg with a level on a leg of the tower. Pour SLOWLY and have the leg holders keep the section vertical as the concrete is poured. Once the hole is filled it will be difficult to correct any lean. Bob ND2L -- ********* Bob Bissett rbissett@monmouth.com ********* From lwbyppp@epix.net Mon Mar 11 07:11:03 1996 From: flanders@znet.groupz.net (Jerry Flanders) Newsgroups: rec.radio.amateur.antenna Subject: Re: Best way to insall a Rohn HBX tower Date: Wed, 06 Mar 1996 04:12:10 GMT Message-ID: <4hj3an$388@news1.sunbelt.net> References: <4hia6a$10bc@chnews.ch.intel.com> tom_boza@ccm.ch.intel.com (WB7ASR) wrote: >I purchased a Rohn HBDX-40 self-supporting tower with the three >four foot long concrete base leg L-stubs. After I dig my base hole >and install the rebar, what is the best way to install the three tower >base leg L-stubs into the hole before the concrete is poored to insure >they will be level and ture once the concrete has been poured? =============================================================== Rohn publishes an EXCELLENT consumer's technical manual that REALLY tells you how to install their stuff. You obviously don't have it. Phone ROHN and ask for it. I am not sure what they call it these days, but if you ask them the above question, they will know just what you need. Jerry W4UKU flanders@groupz.ne From lwbyppp@epix.net Mon Mar 11 07:11:04 1996 From: Jay Newsgroups: rec.radio.amateur.antenna Subject: Re: Best way to insall a Rohn HBX tower Date: Sat, 09 Mar 1996 09:04:48 -0500 Message-ID: <31419000.47B8@fast.net> References: <4hia6a$10bc@chnews.ch.intel.com> <313F2CC0.C71@monmouth.com> > WB7ASR wrote: > > > > I purchased a Rohn HBDX-40 self-supporting tower with the three > > four foot long concrete base leg L-stubs. After I dig my base hole > > and install the rebar, what is the best way to install the three tower > > base leg L-stubs into the hole before the concrete is poored to insure > > they will be level and ture once the concrete has been poured? > Tom, do yourself a BIG favor and get the instruction sheets from Rohn. In it you'l l see how to make a template using a scrap piece of plywood. This template, wit h the L-stubs hanging from it, is then placed over your hole in the ground befor e or during the concrete pour. There is no need to play with the lower tower secti on at all using this method, much easier, much safer, much lighter, less manpower needed during the pour. Myself and one other person was all that was needed w hen we poured the concrete for my Rohn HDBX-48 behind my house. Call Rohn, get th e instructions, you'll be glad you did. Good Luck Jay n2mga@fast.net From lwbyppp@epix.net Mon Mar 11 07:11:05 1996 From: steffey Newsgroups: rec.radio.amateur.antenna Subject: Building a 2m yagi ? Date: Sun, 03 Mar 1996 11:53:44 -0800 Message-ID: <3139F8C8.3BAE@anet-dfw.com> Hello, Can anyone tell me a place on the internet to find the design to build a 2m yagi antenna.( or a shareware program to figure the lengths). thanks in advance, bryan From lwbyppp@epix.net Mon Mar 11 07:11:06 1996 From: iihhss@aol.com (IIHHSS) Newsgroups: rec.radio.amateur.antenna Subject: ButterNut Vertical...Ground Plane on Motor Home..HELP..HELP!!! Date: 2 Mar 1996 23:32:25 -0500 Message-ID: <4hb7cp$4ed@newsbf02.news.aol.com> Reply-To: iihhss@aol.com (IIHHSS) I just bought a Butternut Vertical and will be placing it on my Motor Home. I am very concerned about getting a GOOD GROUND / GROUND PLANE. My motor home has an aluminum sheet roof covered with aluminum roof compound. I think I will be mounting my Butternut on the aluminum ladder that is on the rear of my motor home ( the ladder used to to climb up to the roof ). SO what is the best way to get a GOOD GROUND PLANE? What is the best method of grounding? I have heard about radials ...do I need any type of radial for my Butternut? Oh, by the way I think my Butternut will be apprx. 10-12ft. from the ground to the bottom off the Butternut. PLEASE ANY and ALL help would be GREATLY APPRECIATED.... Thank You, PAT From lwbyppp@epix.net Mon Mar 11 07:11:07 1996 From: 73700.12@compuserve.com (Jim Nuytens) Newsgroups: rec.radio.amateur.antenna Subject: Re: Comet GP9-N vs Diamond X500HNA Date: 7 Mar 1996 04:49:47 GMT Message-ID: <4hlptb$bv0@arl-news-svc-3.compuserve.com> References: <313D20CB.7FAF@intermediainc.com> In message <313D33A4.46B3@intermediainc.com> - Jeff DePolo WN3A writes: :> :>Has anyone had the chance to compare these two antennas? At one of my :>repeater sites, I'm going to be replacing VHF and UHF monoband antennas :>with a single dual-band antenna, and am trying to decide which. I have :>a Diamond X500HNA that I used for a while on the 2m and 440 remote bases :>tied to a repeater, and, although it was OK, it's performance on UHF :>didn't compare favorably to single-band UHF antennas that I've A/B :>compared it to at the same site (Celwave PD-455, Diamond F718A, etc.), :>so I'm wondering if the Comet GP9-N is a better alternative. :> Our group replaced a defective Diamond after 2 years of service with one of these Comet atennas in September 1995. It too early to tell about durability, but patterns appear to be just about indenticle. The one thing that we noiced was that all the phasing sections in the Diamond were crimp-on connections where the Comet's are soldered. Also, the Diamond developed a leak in the upper-most section that then corroded much of the top third of the antenna. Not a resounding testimony for Diamond, IMHO. Unfortunately, both antennas seem to flop around a bit in the wind, so I expect the same problems with the Comet in about 2 years time. :> :>I can't understand why Celwave or Decibel haven't come out with a good :>fiberglass-radomed dual-band antenna yet. From what I've seen, "good" :>and "dual-band" don't go as well together as the ham-grade antenna :>manufacturers might have you believe. :> I can figure it out either. We once toyed around with the idea of enclosing our dual-band antenna in a hollowed out radome, but you don't see people replacing those very often in the first place. Jim Nuytens N3JJA/Delaware Email: V.P., Delaware Repeater Association 73700.12 @ compuserve.com Seitz Technical Products Jim @ Seitz.com Delaware Ham Shack BBS 302-798-2002 All opinions stated above are my own, which probably accounts for their unpopularity. From lwbyppp@epix.net Mon Mar 11 07:11:09 1996 From: Jeff DePolo WN3A Newsgroups: rec.radio.amateur.antenna Subject: Comet GP9-N vs Diamond X500HNA Date: Wed, 06 Mar 1996 01:41:40 -0500 Message-ID: <313D33A4.46B3@intermediainc.com> References: <313D20CB.7FAF@intermediainc.com> Has anyone had the chance to compare these two antennas? At one of my repeater sites, I'm going to be replacing VHF and UHF monoband antennas with a single dual-band antenna, and am trying to decide which. I have a Diamond X500HNA that I used for a while on the 2m and 440 remote bases tied to a repeater, and, although it was OK, it's performance on UHF didn't compare favorably to single-band UHF antennas that I've A/B compared it to at the same site (Celwave PD-455, Diamond F718A, etc.), so I'm wondering if the Comet GP9-N is a better alternative. Whichever antenna I get will be top-mounted. I'm all too familiar with the problems of pattern distortion caused by these flimsy amateur-grade antennas flopping around in the wind. I've been dissapointed with the Hustler 2m/440 dual-bander (both the old and new styles), so that's not an option -- any others you think I should consider? For what it's worth, the new antenna will be replacing a Celwave PD-400 and a Diamond F-22A. The reason for the change is to able to use a higher spot on the tower (the top) for both a UHF voice repeater currently using a side-mounted PD-400 and an APRS digi using a side-mounted F-22A. I'm primarily interested in UHF performance differences. The antenna will be mounted a little shy of 1000' HAAT, so I am also weighing the option of a lower-gain antenna as well in the interest of preventing overshoot across a long, wide valley immediately west of the repeater site. I can't understand why Celwave or Decibel haven't come out with a good fiberglass-radomed dual-band antenna yet. From what I've seen, "good" and "dual-band" don't go as well together as the ham-grade antenna manufacturers might have you believe. --- Jeff -- -=-=-=-=-=-=-=-=-=-=-=-=-=--=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Jeff DePolo WN3A depolo@eniac.seas.upenn.edu Twisted Pair: H:610-337-7383 W:215-387-3059 x300 RF: 442.1 442.2 442.4 443.45 443.8 444.15 449.925 linked From lwbyppp@epix.net Mon Mar 11 07:11:10 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: Connector losses Date: Thu, 07 Mar 96 20:05:26 GMT Message-ID: <4hnfoi$pk4@crash.microserve.net> References: <4hmq97$nqk@crash.microserve.net> <4hmru6$6nt@newsbf02.news.aol.com> w8jitom@aol.com (W8JI Tom) wrote: >I didn't consider that one Jack. Sorta like asking your XYL if you >can buy a new rig and she answers "I don't know"! You know, I get that same response when I ask if she'd prefer a 240 foot tower to a 60, or whether I should replace my dipole with 80 through 10 meter monoband yagis. I have to say though, she's really looking forward to the $30,000 equipment shelter that's going in where the garage used to be. She knows it's an investment that will be here long after the memories of that Antigua trip would be dull and faded. :) 73, Jack WB3U From lwbyppp@epix.net Mon Mar 11 07:11:11 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: Connector losses Date: Thu, 07 Mar 96 13:58:55 GMT Message-ID: <4hmq97$nqk@crash.microserve.net> References: <4hjclh$j9k@news.asu.edu> hamop@aztec.asu.edu (CHARLES J. MICHAELS) wrote: >IMO, the most reliable answer anyone can give is "I don't know". >That's the one answer in life we can absolutely depend on being >correct. Unless they're lying. 73, Jack WB3U From lwbyppp@epix.net Mon Mar 11 07:11:11 1996 From: w8jitom@aol.com (W8JI Tom) Newsgroups: rec.radio.amateur.antenna Subject: Re: Connector losses Date: 7 Mar 1996 09:30:30 -0500 Message-ID: <4hmru6$6nt@newsbf02.news.aol.com> References: <4hmq97$nqk@crash.microserve.net> In article <4hmq97$nqk@crash.microserve.net>, jackl@pinetree.microserve.com (WB3U) writes: >Unless they're lying. > >73, >Jack WB3U I didn't consider that one Jack. Sorta like asking your XYL if you can buy a new rig and she answers "I don't know"! From lwbyppp@epix.net Mon Mar 11 07:11:12 1996 From: "Oliver P. Timme" Newsgroups: rec.radio.amateur.antenna Subject: construction plan for a 2m beam Date: Wed, 06 Mar 1996 09:34:59 +0100 Message-ID: <313D4E33.546F@sercon.ch> References: <3139F8C8.3BAE@anet-dfw.com> Hello Im looking for a design plan to build a 2m beam (three or five elements). Has anyone such a plan (you can mail it). Or know anyone a location on the net where I can get such a construction plan. Thanks. 73 Oliver From lwbyppp@epix.net Mon Mar 11 07:11:13 1996 From: rcrgs@regcon.syr.servtech.com (Robert G. Strickland) Newsgroups: rec.radio.amateur.antenna Subject: Re: Cubical Quad Antennas for HF Date: Thu, 07 Mar 1996 15:40:35 -0500 (EST) Message-ID: <4hneh4$esl@murphy2.servtech.com> References: <4fsgkr$2v3@btr0x6.hrz.uni-bayreuth.de> <4hhe26$7pt@murphy2.servtech.com> <4hjvvd$326@nnrp1.news.primenet.com> mchasse@primenet.com wrote: >Do you have a way to contact Lighting Bolts Antennas >73's >Mike There phone number is: [412] 530-7396 Mike Duddy, WB2ECM ...Robert Robert G. Strickland KE2WY rcrgs@regcon.syr.servtech.com Syracuse, New York From lwbyppp@epix.net Mon Mar 11 07:11:14 1996 From: mchasse@primenet.com Newsgroups: rec.radio.amateur.antenna Subject: Re: Cubical Quad Antennas for HF Date: 6 Mar 1996 05:21:01 -0700 Message-ID: <4hjvvd$326@nnrp1.news.primenet.com> References: <4fsgkr$2v3@btr0x6.hrz.uni-bayreuth.de> <4hhe26$7pt@murphy2.servtech.com> Reply-To: mchasse@primenet.com In <4hhe26$7pt@murphy2.servtech.com>, rcrgs@regcon.syr.servtech.com (Robert G. Strickland) writes: >Charlie... >I have been using a Lightning Bolt Quad for four years in Central NY. >We get some strange weather here, and the LBQ has held up fine. I have >the five band version, and I'm pleased with its performance. Be that >as it may, I am planning to redesign/reconstruct it this summer. This >does not reflect on the original design/construction. I've been >modeling quads with EZNEC, and I'd just like to put my "knowledge" to >use. LBQ uses aluminum welding wire. It is a bit difficult to work >with, but its strength to weight ratio is excellent. While one cannot >predict these things, I have the sense that it could stay up there for >some time before anything happens to the wires - what ususally goes in >a quad. Performance wise, quads are the best compact beam there is. >You just can't get a better performing antenna in such a small space. >....Robert > > > >Robert G. Strickland KE2WY >rcrgs@regcon.syr.servtech.com >Syracuse, New York > Do you have a way to contact Lighting Bolts Antennas 73's Mike From lwbyppp@epix.net Mon Mar 11 07:11:15 1996 From: zaax@aol.com (ZaaX) Newsgroups: rec.radio.amateur.antenna Subject: Discone Radiation Patterns? Date: 8 Mar 1996 01:25:02 -0500 Message-ID: <4hojru$qq2@newsbf02.news.aol.com> Reply-To: zaax@aol.com (ZaaX) Can anyone out there tell me what type of radiation pattern a VHF/UHF discone exhibits? Is it roughly equal to a 1/4 wave or what? I looked in all of my antenna books (including the Arrl antenna book) but could find nothing about this. Any info will be greatly appreciated! 73 Zack Schindler N8FNR EN82KL From lwbyppp@epix.net Mon Mar 11 07:11:16 1996 From: rtm@netgate.net (Bob Martin N6MZV) Newsgroups: rec.radio.amateur.antenna Subject: Re: Discone Radiation Patterns? Date: Fri, 08 Mar 1996 19:35:31 -0800 Message-ID: References: <4hojru$qq2@newsbf02.news.aol.com> In article <4hojru$qq2@newsbf02.news.aol.com>, zaax@aol.com (ZaaX) wrote: > Can anyone out there tell me what type of radiation pattern a VHF/UHF > discone exhibits? Is it roughly equal to a 1/4 wave or what? I looked in > all of > my antenna books (including the Arrl antenna book) but could find nothing > about this. Any info will be greatly appreciated! > > 73 Zack Schindler > N8FNR > > EN82KL Roughly like a 1/4 wave, with the take-off angle increasing with frequency 73- -- Bob Martin N6MZV * rtm@netgate.net From lwbyppp@epix.net Mon Mar 11 07:11:17 1996 From: jbmitch@vt.edu (John Mitchell) Newsgroups: rec.radio.amateur.antenna Subject: Re: Erecting 100 ft tower on 800-900ft hill Date: 8 Mar 1996 01:22:46 GMT Message-ID: <4ho256$37k@solaris.cc.vt.edu> References: <4hfjhg$ij6@ulowell.uml.edu> In article <4hfjhg$ij6@ulowell.uml.edu>, bcharbon@jupiter.cs.uml.edu says... > >Hi everyone, > I am planning to erect a 100 ft tower (Rohn 55) on a hill of 800-900ft >elevation. I realize that the winds will be strong up here, so I plan on >reinforcing everything. This is my question: what can I do to the tower >and / or antennas to make them stronger and more wind resistant? A must read: Physical Design of Yagi Antennas, by David B. Leeson, W6QHS ARRL bookstore. around 20 dollars This book not only tells you how to strengthen antennas and towers for hill top mounting, but also explores the propagation take off angle associated with sloping terrain ( e.g. you can actually mount an antenna too high!!) Highly recommended 73, MUR From lwbyppp@epix.net Mon Mar 11 07:11:18 1996 From: glawson@inav.net (Gayle Lawson) Newsgroups: rec.radio.amateur.antenna Subject: Re: Erecting 100 ft tower on 800-900ft hill Date: Tue, 05 Mar 1996 02:53:17 GMT Message-ID: <4hgahh$84k@composer.inav.net> References: <4hfjhg$ij6@ulowell.uml.edu> bcharbon@jupiter.cs.uml.edu (Brad Charbonneau) wrote: >Hi everyone, > I am planning to erect a 100 ft tower (Rohn 55) on a hill of 800-900ft >elevation. I realize that the winds will be strong up here, so I plan on >reinforcing everything. This is my question: what can I do to the tower >and / or antennas to make them stronger and more wind resistant? > One ham suggested that I line the inner part of the antenna elements wit h >rope in order to prevent the oscillations of the elements in the wind. He >also recommended that I insert a thinner metal tubing piece inside part of th e >boom in order to make the boom stronger. I have wondered if increasing the >amount of guying to the tower (ie every 15 ft rather than say every 25-20ft) would make the tower stronger against the wind... > If anyone has any comments, or anything else they know of that I could >do to make this setup more wind resistant, I'd really appreciate it. Maybe >building my own antennas from scratch (w/ computer modeling prog) would make >the strongest antennas...Any suggestions/info is greatly appreciated! > Thanks in advance! >73, Brad NZ1Y Brad: Sounds like a winner of QTH. Rohn has some application sheets that you can request which will give you some insites on guying and wind rating of the model 55 tower (25 and 45 also). Also you might E-mail Steve N0YVY ( sawyers@inav.net) and ask for his model 55 calculations. Steve is a mechanical engineer ( with PE certificate) that has some how gone crazy and now writes software for a living. More guy wires may not be the answer, remember that guyed towers vector the wind force down to the base, they are rated by the force that is required to collapse the bottom section. As you add more guy wires you put more preload on the bottom section leaving less margin for the forces created by the wind. I believe that Ham Radio magazine had several articles on how towers were design etc. You might try finding these. Gayle W0FO Gayle Lawson W0FO From lwbyppp@epix.net Mon Mar 11 07:11:19 1996 From: tomb@lsid.hp.com (Tom Bruhns) Newsgroups: rec.radio.amateur.antenna Subject: Re: feed point impedance calc for length of wire or tubing ? Date: 7 Mar 1996 16:52:48 GMT Message-ID: <4hn490$fv2@hpcvsnz.cv.hp.com> References: <4hm8bn$a3g@news.rrz.uni-koeln.de> Thilo Kootz (Kootz@apollo.ph1.uni-koeln.de) wrote: : VE4KLM wrote: : >Given a length of wire or tubing, is there a practical formula I : >can use to determine the feed point impedance for the following : >scenarios (the resistive component anyway) ? : > 1. length of wire or tubing, end fed : > 2. length of wire or tubing, center fed (dipole like) : >If the formula includes natural inductance & capacitance, even better. : if you get a positive answer, please let me know. i posted a similar : question about 4 weeks ago. but no usable answer ! : 73 thilo dl9kce Well, one practical formula is implemented in NEC. It's made practical by the availability of computing power. The question asked is not an easy one to answer in a simple textbook fashion, though there are some reasonable engineering approximations. Although NEC will give you numerical answers, I would suggest that you do some reading to get a better qualitative and semi-quantitative understanding of what's going on. I highly recommend Joseph Boyer's "The Antenna-Transmission Line Analog" from April and May, 1977, "Ham Radio" magazine. It really does help you calculate feedpoint impedances, though it refers back to a book, King, Mimno and Wing's "Transmission Lines, Antennas and Wave Guides," for graphs of resistance versus length and diameter. I highly recommend that book, too, though finding it may be a problem. I have to say I've learned far more from that article and that book than from all the discussions I've seen posted here. But if all you want is numerical answers and not understanding, by all means get your hands on some NEC implementation. I use Roy Lewallen's EZNEC and like it, but there are others that will do the trick too, including freeware. And trying out different configurations in NEC can really help drive home the ideas you learn from your reading, too. (Also be aware that for the original question, the answer depends on the environment, not just the radiator the feedline is connected to. This is especially true for the end-fed wire, which must be fed against _something_. The answer will be different feeding against an infinite ground plane or feeding in freespace against a 1/4 wave long stub, as in a J-Pole, or feeding against, say, a pie tin...) -- Cheers, Tom tomb@lsid.hp.com PS -- I have a standing offer to make copies of the Boyer article for the cost of postage and copying, since Ham Radio mag is no longer around and it may be difficult for most folk to find this article. I'll include copies of some relevant pages of King's book, too. From lwbyppp@epix.net Mon Mar 11 07:11:21 1996 From: hamop@aztec.asu.edu (CHARLES J. MICHAELS) Newsgroups: rec.radio.amateur.antenna Subject: Re: feed point impedance calc for length of wire or tubing ? Date: 9 Mar 1996 20:26:29 GMT Message-ID: <4hsphl$kdb@news.asu.edu> VE4KLM asked iven a length of wire or tubing, is there a practical formula I can use to determine the feed point impedance for the following scenarios (the resistive component anyway) ? 1. length of wire or tubing, end fed 2. length of wire or tubing, center fed (dipole like) If the formula includes natural inductance & capacitance, even better. Thanks in advance, Maiko Langelaar VE4KLM Yes, see Shelkunoff *ELECTROMAGNETIC WAVES* VanNostrand 1943 chapter XI Or, use ELNEC for both getting center fed as fee/// free space value and free space end fed by treating as a monopole over perfect \ earth. of course either of these will be different if antenna is below about .2 wavelengths over real earth. Charlie, W7XC -- From lwbyppp@epix.net Mon Mar 11 07:11:22 1996 From: hamop@aztec.asu.edu (CHARLES J. MICHAELS) Newsgroups: rec.radio.amateur.antenna Subject: Re: feed point impedance calc for length of wire or tubing ? Date: 9 Mar 1996 20:40:06 GMT Message-ID: <4hsqb6$lk1@news.asu.edu> In my reply to VE4KLM's question iven a length of wire or tubing, is there a practical formula I can use to determine the feed point impedance for the following scenarios (the resistive component anyway) ? 1. length of wire or tubing, end fed 2. length of wire or tubing, center fed (dipole like) If the formula includes natural inductance & capacitance, even better. Thanks in advance, Maiko Langelaar VE4KLM I mispelled Schelkunoff See Schelkunoff *ELECTRO-MAGNETIC WAVES* VanNostrand 1943 chapter XI. You need not solve the complicated equations as he provides a set of curves of length against K which is a simple equation in the text. Ues... Use the *half values * for a monople to get the end fed casel. Of course these will only apply to an antenna more than about .2 wavelengthts above real earth since local induction field induced losses are not included Charlie, W7XC -- From lwbyppp@epix.net Mon Mar 11 07:11:23 1996 From: tnicolai@neosoft.com (Tom Nicolaides) Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.equipment Subject: FS: Wilson 77 foot Self-supporting tower Date: Sat, 09 Mar 96 16:14:52 GMT Message-ID: <4hsalr$75m@uuneo.neosoft.com> Wilson ST77 Tubular crankup tower: - motorized winch for hoisting - built in gin pole with hand winch for tilt-over - Ham 4 rotor - Cushcraft A3S three element tri band beam - Cushcraft Rotatable dipole for 30, 17 and 12 meters - Hi-gain 40 meter rotatable dipole - Ringo Ranger 2 for two meters - tower rated for 17 sq ft wind area $1700 takes all, shipping to be negotiated call Tom Nicolaides, WA5ZCC 504.649-3847 email tnicolai@neosoft.com From lwbyppp@epix.net Mon Mar 11 07:11:24 1996 From: kerbugh@aol.com (KERBUGH) Newsgroups: rec.radio.amateur.antenna Subject: Re: GAP VERTICLES Date: 9 Mar 1996 20:22:38 -0500 Message-ID: <4htasu$job@newsbf02.news.aol.com> References: <4hb3i1$32b@newsbf02.news.aol.com> Reply-To: kerbugh@aol.com (KERBUGH) I have a Challenger ground mounted (using the GAP counterpoise kit) approx. 30 from the house. Too many overhead powerlines cris-crossing the back yard so I had to put it in the side yard. With no guying it has stood up rather well, except that it has developed a slight 'lean' :-\ so guying would be suggested. While I am *not* very active as a DX'er, my experience in the past 5 months suggests that it is no better than my trusty old dipole. This may be due to 1) me 2) location or 3)conditions but I would suggest not to expect miracles. Two things that make a vertical worth while is being able to switch bands without re-tuning and the ability to work 80 meters. At a distance of 60 feet you shouldn't have any trouble tuning your vertical as supplied, being so close to the house I have trouble tuning 12 meters and I had to mess with 20 meters (added approx. 6" to the 20 meter tuning rod) to get an acceptable SWR. Hope this helps a little. Alan Kerbugh@aol.com From lwbyppp@epix.net Mon Mar 11 07:11:24 1996 From: phill@voicenet.com (Phil Leinhauser) Newsgroups: rec.radio.amateur.antenna Subject: GPS antenna plans? Date: Fri, 8 Mar 1996 00:43:36 LOCAL Message-ID: I think I remember seeing plans for a roof mounted GPS antenna in a magazine somwhere but I can't remember where. Does anyone know of a good design for using it while mobile? I think the one I saw was made of some pieces of pc board (very simple). Thanks & 73 Phil KE3VQ From lwbyppp@epix.net Mon Mar 11 07:11:25 1996 Newsgroups: rec.radio.amateur.antenna Subject: help with indoor antenna for Kenwood TS450SAT Message-ID: <1996Mar9.135005.2544@hobbit> From: desaid@marshall.edu (Dinakar) Date: 9 Mar 96 13:50:05 EDT Hello all: I would like to build or buy indoor antenna for my HF radio (kenwood TS450sAT) with internal antenna tuner. I would like to know which antenna will be good and if it works on all bands 10-80 M would be nice. I would appreciate, if you could give some antenna construction plans. I will be traveling to Japan very soon and I would like to install antenna indoor. Moreover, I have heard that apartments in Japan are really small and I dont have any idea what will be the dimensions of apartment would be. I would like to use only the internal antenna tuner as external that I have is some what bulky to carry with me. Please let me know what kinda of antenna I can build so that I can feed with just coax directly from antenna to radio. thank you very much for your help. 73 Dinakar KG8OE desaid@marshall.edu From lwbyppp@epix.net Mon Mar 11 07:11:26 1996 From: Cecil Moore Newsgroups: rec.radio.amateur.antenna Subject: Re: how can a duckie be 4-7db? Date: 7 Mar 1996 23:27:04 GMT Distribution: world Message-ID: <4hnrc8$192d@chnews.ch.intel.com> References: <4hgmgi$par@mark.ucdavis.edu> <4hhehb$8nu@newsbf02.news.aol.com> w8jitom@aol.com (W8JI Tom) wrote: >In article <4hgmgi$par@mark.ucdavis.edu>, szhall@rocky.ucdavis.edu (Jeff >Hall) writes: > >> >> I was reading an ad about rubber duckie for your hand held that have a >>4-7db. and yet you can get a large out side 2 meter ant which the same >They can be MINUS 4 to 7 dB, but certainly not plus (in reference to a 1/2 >wave or isotropic radiator) I was assuming 4-7db meant 4 minus 7 db. :-) 73, Cecil, KG7BK, OOTC (not speaking for my employer) From lwbyppp@epix.net Mon Mar 11 07:11:27 1996 From: hamop@aztec.asu.edu (CHARLES J. MICHAELS) Newsgroups: rec.radio.amateur.antenna Subject: Re: How much RF pwr does an ant tuner consume? Date: 9 Mar 1996 20:06:12 GMT Message-ID: <4hsobk$in2@news.asu.edu> It has been pointed out that measurements of current, voltage and SWR on a balanced line can provide data for calculation of poer/// power. Be careful that the insertion of measurement devices into the line does not change its operation by the stray or paracitic impedances intoduced by the measurement system. Charlie, W7XC -- From lwbyppp@epix.net Mon Mar 11 07:11:28 1996 From: drranu@holly.ACNS.ColoState.EDU (Emarit Ranu) Newsgroups: rec.radio.amateur.antenna Subject: Re: is kraus alive? Date: 8 Mar 1996 17:55:40 GMT Message-ID: <4hpsas$lbk@yuma.ACNS.ColoState.EDU> References: <031bkck60.alamito@banana.speed.satlink.net> Anibal Aguirre (anibal@banana.speed.satlink.net) wrote: : i`d like to know if the autor of "the antenna bible" is alive today. : please sorry...sorry for my ignorance. : if he`s alive, i`d like write him. : sorry again. : 73, anibal. : LU4DVJ My Electromagnetics book copyrighted 1992 by him says he is "teaching while serving as a consultant to government and industry". -- -Emarit, KG0CQ 73's drranu@holly.ColoState.EDU Electrical Engineering, Colorado State Univeristy Packet: KG0CQ@KF0UW.#NECO.USA.NOAM All generalizations are bad. Censorship: ###### _._ __. _____ _._. __._ From lwbyppp@epix.net Mon Mar 11 07:11:29 1996 From: moritz@ipers1.e-technik.uni-stuttgart.de () Newsgroups: rec.radio.amateur.antenna Subject: Re: J-pole Date: 11 Mar 1996 09:00:20 GMT Message-ID: <4i0q34$328q@info4.rus.uni-stuttgart.de> References: >I later read where someone insulated the twinlead from the >inside of the pipe and all was well. I blv they used some non-conductive >foam that they split lengthwise and inserted the twinlead then fit the >whole thing into the plastic tube. Hi Wayne, Twin lead is not rally a very good idea for a j-pole. So all the effort with weatherproofing, foam and the rest is a bit of a waste. Try to build your antenna from *metal* and not from plastic. 73, Moritz DL5UH From lwbyppp@epix.net Mon Mar 11 07:11:29 1996 Newsgroups: rec.radio.amateur.antenna Subject: KLM phone number Message-ID: From: "C.M. (Chris) Christensen" Date: Wed, 6 Mar 1996 14:19:35 -0600 Distribution: world I have been trying to reach KLM to order some parts for a KT34A but both phone numbers I have are incorrect. If you have a working number for them please e-mail it to me. Thanks es 73, Chris AC0M cchris@sunbird.usd.edu From lwbyppp@epix.net Mon Mar 11 07:11:31 1996 From: k8cxm@one.net (Jim Leder) Newsgroups: rec.radio.amateur.antenna Subject: Re: Need Info on G5RV Antenna Date: Sat, 09 Mar 1996 00:41:18 GMT Message-ID: <4hqk49$qt@news.one.net> References: <4ho8ga$ici@sloth.swcp.com> n5zgt@swcp.com (Brian Mileshosky) wrote: >Hello Everybody, > I am thinking of buying a G5RV antenna. Are these antennas pretty >good? How about on 80 and 40? And I have heard they can be used on 160 >meters. How does it to on that band? > All information would be greatly appreciated! Thanks! >Best of 73, >Brian, N5ZGT... >________________________________________________________________________ > Boy Scouts of America Amateur Radio > J.A.S.M. - Troop 41 N5ZGT > Albuquerque, NM Packet: N5ZGT @ KC5IZT.ALBQ.NM.USA.NA > Great Southwest Council Internet: n5zgt@swcp.com > O.A. Lodge 66 >_______________________________________________________________________ I've had one up I made, real easy to do, in an inverted vee configuration. The center is only 40 feet up but it still works ok. I won't say its the best antenna I've ever had, but for the cost and the effort its pretty good. It is best on 40/20 and ok on 80. Not much good on 15/10. I only run a barefoot TS450sat into it and the tuner is required. Never even tried it on 160 but saw some other posts suggesting ways to do that. Jim ...K8CXM From lwbyppp@epix.net Mon Mar 11 07:11:32 1996 From: destiny_software@mindlink.bc.ca (destiny admin) Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.digital.misc,rec.radio.amateur.equipment,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.amateur.policy Subject: New Radio Program Date: 7 Mar 1996 00:38:04 GMT Message-ID: <4hlb5c$rns@fountain.mindlink.net> Destiny Software is a developer of video games like JAM! (shareware), Darkseed II and Blood Bowl. You can check out our WEB site at: http://www.destiny-software.com/destiny Now we're experimenting with RADIO! We have just successfully broadcast good quality music and speech over the internet (receiving with a 28 800 modem). (Our compression algorithm is much faster and better quality than others we've tried.) We plan to allow non-commercial users to broadcast for free, encouraging a wide variety of viewpoints in this new medium. Commercial users are welcome to participate in BETA testing. The compression is in real time on a 486, so we will support live broadcasts as soon as we finish the initial testing. So here's the scoop - we're looking for BETA testers. If you would like to become a broadcaster, you need: 1. A permanent IP address. 2. A dedicated machine (or permission to run background tasks) 3. You are either linked to the MBONE or you have a fast connection 4. If you are using a non-windows server, we may need access to your account to compile for your particular machine. Basically, you fill your hard drive with samples and a script file to organize playback. (The player will repeat the script when it finishes). Later we will upgrade so that broadcasters can go live by plugging a signal into a PC sound card. Listeners will enter your address into the radio program and voila, your broadcast will begin playing. The radio feature will be built into our soon to be released freeware browser. If you're interested, send email. Thanks! From lwbyppp@epix.net Mon Mar 11 07:11:34 1996 From: richardm@advance.COM.AU (Richard Murnane x2175) Newsgroups: rec.radio.amateur.antenna Subject: Organic verticals again Date: 7 Mar 96 17:52:00 GMT Message-ID: <313E4F7F@central.advance.com.au> Hi all, In case anyone is still interested in loading up trees, page 19 of the March 1996 issue of the Wireless Institute of Australia's journal, "Amateur Radio" has an article by Steve Bushell VK3HK on this subject. Quick precis: Steve fed an Australian Blue Gum (eucalyptus) with a 300 ohm balanced line, one side connected to a stake in the ground at the base of the tree (doesn't sound very balanced to me, but anyway...) The other side side joined by an alligator clip to a screwdriver hammered into the tree about a metre from the ground. He fed this from the transmitter via an ATU (I suspect it was a standard unbalanced tuner) He says he got 5 by 8 reports from stations in Perth (west coast, VK6), and Cairns (northern VK4) on 40 metres He says he also heard stations in Southern Europe and South America, but didn't call them as there was a contest on. He also notes best results using a feedpoint about 1/8th wavelength above ground, and the ground connection was essential. Steven suggests that Canadian Spruce, Baltic Pine, Californian Redwood and English Elm would provide good results (on what basis he makes this comment, other than posibly being tongue in cheek, I don't know...) 73 Richard VK2SKY From lwbyppp@epix.net Mon Mar 11 07:11:35 1996 From: parf@aol.com (Parf) Newsgroups: rec.radio.amateur.antenna Subject: Re: Patch-type antennas Date: 8 Mar 1996 22:37:03 -0500 Message-ID: <4hqucv$l44@newsbf02.news.aol.com> References: <4hpmjr$e7a@news.ios.com> Reply-To: parf@aol.com (Parf) I believe if you look in QST over the past year there was an article w/ references on a patch for APRS/ packet. 73, Dale WA2YPY From lwbyppp@epix.net Mon Mar 11 07:11:35 1996 From: zaax@aol.com (ZaaX) Newsgroups: rec.radio.amateur.antenna Subject: Portable 6 Meter Yagi's ? Date: 6 Mar 1996 08:36:34 -0500 Message-ID: <4hk4d2$7a9@newsbf02.news.aol.com> Reply-To: zaax@aol.com (ZaaX) Does anyone manufacture 2 or 3 element Yagi's for the 6 metre band that breakdown for travel? Also, does anyone know of any plans for a simple 2 element Yagi for this band. Any info on this will be greatly appreciated! 73 Zack Schindler N8FNR From lwbyppp@epix.net Mon Mar 11 07:11:37 1996 From: ignacy@num.ads.uga.edu (Ignacy Misztal) Newsgroups: rec.radio.amateur.antenna Subject: Re: Q: How would a 80m Magnetic Loop antenna look like? Date: 6 Mar 1996 14:32:26 GMT Message-ID: <4hk7lq$d8l@hobbes.cc.uga.edu> References: <42386306@clobber.mos.unterland.de> Reply-To: ignacy@uga.cc.uga.edu (Ignacy Misztal) In <42386306@clobber.mos.unterland.de>, "Martin Biallas" writes: >Hello! > >Unfortunately I have no opportunity to establish a good 80m antenna. (I live in a >flat in a house that I dont own.) Recently I heard about an antenna called Ma gnetic >Loop. It was said that this antenna typ allows -although it is worse than an half >wave Dipol- nice QSOs. Or in other words: its better than nothing. :) >Now my question is how must a magnetic loop for the 80m band look like? And c ould >anyone send me (via email) the meassurements of that antenna? Maybe there are even >www-sites which contain such a plan ... For decent performance, a 20m loop with a 1/4 inch copper tube needs to be about 3 ft in diameter. This translates to 12 ft on 80m. Another factor is attenuation by surrounding objects. If the loop is inside, most of the radiation may end up in structures. Ignacy Misztal Ham radio: NO9E, SP8FWB E-mail: ignacy@uga.cc.uga.edu University Of Georgia, 203 L-P Bldg., Athens, GA 30602 tel. (706) 542-0951 From lwbyppp@epix.net Mon Mar 11 07:11:38 1996 From: graham@southlin.demon.co.uk (Graham Seale) Newsgroups: rec.radio.amateur.antenna Subject: Re: Q: How would a 80m Magnetic Loop antenna look like? Date: Fri, 08 Mar 1996 11:45:04 GMT Distribution: world Message-ID: <19960308.114504.56@southlin.demon.co.uk> References: <42386306@clobber.mos.unterland.de> <4hmad9$4v9@sun0.urz.uni-heidelberg.de> <4hn2m8$mqt@zdi.informatik.uni-stuttgart.de> Reply-To: graham@southlin.demon.co.uk In message <4hn2m8$mqt@zdi.informatik.uni-stuttgart.de> Wolfgang Gellerich wro te: > In article <4hmad9$4v9@sun0.urz.uni-heidelberg.de>, s17@aixterm6.urz.uni-hei delberg.de (Joachim Seibert) writes: > > |> Hello Martin! > |> I am using a double loop with a diameter of 1m for 40 and 80. Give's a go od > |> performance with my qrp-rig. By the way: I am forced to use it indoor... > > That is interesting. Theory says that a loop of 1m duameter has an efficienc y > of about 1% on 80m. What are your experiences concerning dx? What reports > do you get ? > > vy 73, Wolfgang DJ3TZ > Hi Wolfgang You are correct about efficiency. It may not even be as good as 1%. A magloop, like a vertical, is a very high Q structure. And also it is very short compared to the wavelength. The radiation resistance will be *very* low. This is why such loops are constructed of 22mm or thicker copper pipe without any joints if possible. A 1metre dia loop is too small for 80m. (Rr < 0.0004 ohms!). Roberto Craighero (I1ARZ) is probably one of the most experienced loop constructors, and has published designs showing an 80m loop as a square of 2.5m each side made of 40mm diameter copper. This has a Rr of 0.023 ohms and loop resistance of 0.04 ohms, and could reach an efficiency of 36%. The loop bandwidth on 80m is only (just!) wide enough for SSB. Magnetic loops, if implemented properly, can be extremely good compared to the poor performance of the average Ham wire antenna when comparing reports. I have now apprecated the advantages/disadvantages of magloops, and I consider their "special" property to be that the field shape is like that of a dipole, but with the magnetic and electric components transposed. I am keen to constru ct a second loop (the first being a very poor attempt!). 73's G4WNT -- Graham Seale From lwbyppp@epix.net Mon Mar 11 07:11:39 1996 From: w8jitom@aol.com (W8JI Tom) Newsgroups: rec.radio.amateur.antenna Subject: Re: Q: How would a 80m Magnetic Loop antenna look like? Date: 10 Mar 1996 10:26:35 -0500 Message-ID: <4husbb$728@newsbf02.news.aol.com> References: <19960308.114504.56@southlin.demon.co.uk> In article <19960308.114504.56@southlin.demon.co.uk>, graham@southlin.demon.co.uk (Graham Seale) writes: > >Magnetic loops, if implemented properly, can be extremely good compared to >the poor performance of the average Ham wire antenna when comparing reports. >I have now apprecated the advantages/disadvantages of magloops, and I >consider >their "special" property to be that the field shape is like that of a dipole, >but with the magnetic and electric components transposed. I am keen to >construct >a second loop (the first being a very poor attempt!). > >73's G4WNT Hi Grant, I've built some small loops here, and like yours they are Electromagnetic, hi. That let's me communicate over a large distance. ;-) Anyway, the most critical thing I've found...other than the conductor (it must have a lot of smooth surface area and preferably be tubing rather than flat stock).... is the capacitor and the connections to the capacitor. I've had poor sucess with any dielectric in the capacitor other than air or vacuum, and the cap should be densely constructed with no current in sliding pressure contacts. Also if the loop is made from woven wire or braid it KILLS the performance. CATV hardline (using the outer conductor) works great, braided coax stinks. 73 Tom From lwbyppp@epix.net Mon Mar 11 07:11:41 1996 From: kr4tg@mindspring.com (mike del pozzo) Newsgroups: rec.radio.amateur.antenna Subject: Re: QUAD QUESTIONS... Date: Thu, 07 Mar 1996 14:03:55 GMT Message-ID: <4hmqce$p6k@brickbat.mindspring.com> References: <4hjufs$jii@linet06.li.net> topanga@newshost.li.net (Keith Smith) wrote: >I'm looking for some info on quads...Should I buy or make my own?? Are >they worth making-and if not, what's the best brand to purchase?? Thanks >for your help in advance. Keith-AC6CX topanga@li.net Hello Keith, in reguards to which Quad system is best, you have to first decide for yourself if the antenna in question will serve all your purposes. I'm guessing that you are in California - so ice may not be a factor here. so then it is a question as to what bands and or no of elements will suit your need. Secondly consider putting up a quad is not an easy chor to accomplish. it takes careful planning , and lots of bodies to make sure it will reach it's destination in one piece. Thirdly If the Quad you wish to utilize is of a larger breed ( 4 elements or better ) then Construction is vital to survival. The Boom on these monsters should be at least 3 in. to 4 in and the spiders ( spreader supports) should be strong enough to survive the maximum wind loading , even if it doesn't happen at your QTH. Finally , PRICE is always a factor. You get what you pay for in a Quad - is the truth. Imagine for a moment that you live in Moscow and with the heavy snow and occasiopnal ice storms " Will My antenna survive ? " This may be severe overkill but in the long run it will prove to be a worthy investment. I have a 4 element Cubex that has already stood up to icing ( mild ) and seems to hold up OK to wind loading. We shall see next time a Hurricane comes along though Atlanta W/ 70+ mph wind. I'll wish you good luck in your search and I hope I have helped somewhat. 73 , Gud DX'ing KR4TG, Mike Some manufacturers to look at: Cubex Gem Quads Antenna Mart all of which should have ads in QST or CQ for catalog info......... From lwbyppp@epix.net Mon Mar 11 07:11:42 1996 From: topanga@newshost.li.net (Keith Smith) Newsgroups: rec.radio.amateur.antenna Subject: QUAD QUESTIONS... Date: 6 Mar 1996 11:55:40 GMT Message-ID: <4hjufs$jii@linet06.li.net> I'm looking for some info on quads...Should I buy or make my own?? Are they worth making-and if not, what's the best brand to purchase?? Thanks for your help in advance. Keith-AC6CX topanga@li.net From lwbyppp@epix.net Mon Mar 11 07:11:43 1996 From: Mike Sims Newsgroups: rec.radio.amateur.antenna Subject: Re: QUAD QUESTIONS... Date: Sat, 09 Mar 1996 23:09:40 -0500 Message-ID: <31425604.7345@interserf.net> References: <4hjufs$jii@linet06.li.net> <4hqg1v$k1r@murphy2.servtech.com> Robert Strickland wrote: > > topanga@newshost.li.net (Keith Smith) wrote: > > >I'm looking for some info on quads...Should I buy or make my own?? Are > >they worth making-and if not, what's the best brand to purchase?? Thanks > >for your help in advance. Keith-AC6CX topanga@li.net > > Keith... > I bought, assembled, put up and am happy with the Lightening Bolt > Antenna/quad. They offer several models. I have the 5-band, 2el one. > Some thoughts... It was not difficult to assemble or get up in the > air. It did take allot of ground space to assemble each bay; they are > very big. Getting it in the air was "simple." The LBA uses an 8ft boom > with a spider on each end. I put the boom in the mast mount, pulled it > to one end, hauled the bay up, bolted it on, pushed the mast to the > other end, hauled up the second bay and bolted in in place. I had > three people plus me: one on the jin pole line and two each holding > light line that was passed through the lower part of the bay arms. > These two people held on to the lines as the bay went up. They could > hold it away from the house/etc. Now, if you have a 3+el quad, this > system obviously won't work. You'd have to assemble it some other way. > I can comment more on this if you'd like. > > As far as making verses buying: > You'd probably want to buy some good spider mounts unless you like > mechanical construction/alumminum welding/etc. You'll have to buy the > spreaders, usually fibergass of one sort or another. You buy the wire. > By the time you buy all the pieces, you're probably ahead getting a > "kit" quad and putting it together. Like anything, you can go cheap > and you can go ritzy. It's a nice feeling not worrying about what's up > there and when will it break. So, you probably go ritzy. given that > decision, i'd guess that buying is the way to go. The exception would > be if you had access to "stuff" that you'd need. > > I'm a real fan of the quad. It's allot easier to play around with one > than it is with yagis. Again, if you'd like some more comments or > answers to specific questions, let me know. Good luck. > > ...Robert > > Robert G. Strickland > rcrgs@regcon.syr.servtech.com > Syracuse, New YorkKeith, Built a four element quad out of central vacuum cleaner pipe, 1 1/2 inch angle aluminum, hose clamps, muffler clamps, three in aluminum irrigation pipe and a 18 X 12 inch 1/4 inch aluminum plate for the boom to mast mount. Used torsion lines to strengthen the boom. By the way, the ant. is used on 40ty thru 10 meters. The ant. is based on the design in the 1994 July CQ mag. It is on a crank up tower. Rented a "man lift" from a local rental place (transportable in a small pickup truck) and with the help of several others was able to raise the assembled 40ty meter driven and reflector elements (include directors for 20ty thru 10 meters and reflector elements for 20ty thru 10 meters as well). It has survived the winter in north central Virginia. We have had more snow than any winter on record this year. Winds have gusted up to 50 mph. Not a lot of ice this year though. It works for me. Mike, K4GMH (nas@intersef.net) From lwbyppp@epix.net Mon Mar 11 07:11:44 1996 From: Mike Wendland Newsgroups: rec.radio.amateur.antenna Subject: R7 Date: Sat, 02 Mar 1996 17:12:35 -0500 Message-ID: <3138C7D3.4C47@wdiv.com> I just inherited an R-7 antenna from my brother in law, who has passed away. The only problem is, there's no instruction book with the measurements for each segment and how to attach the matchbox. Can anyone fax/e-mail me a copy? I also received his Yaesu FT-757GXII... no manual, of course. ANy ideas on where to find one? -- ================================================ Mike Wendland, K8ZRH mikew@wdiv.com From lwbyppp@epix.net Mon Mar 11 07:11:45 1996 From: raiar@inlink.com (Gary V. Deutschmann, Sr.) Newsgroups: rec.radio.amateur.antenna Subject: Re: Rabbit Ears Question... Date: Thu, 07 Mar 1996 20:07:09 GMT Message-ID: <4hnf6t$68@news1.inlink.com> References: <4hletj$2gq@cloner2.ix.netcom.com> an485930@anon.penet.fi (Praetorian) wrote: >Hey All, is there any way to signifigantly increase the reception of a >pair of rabbit ears without buying cable?? I am on the 2nd floor of >the house, and reception is ony good on one or two channels. >any suggestions??? >andrew Why not build a folded dipole from 300 ohm twin lead and run it around your walls at the ceiling. TTUL Gary From lwbyppp@epix.net Mon Mar 11 07:11:46 1996 From: an485930@anon.penet.fi (Praetorian) Newsgroups: rec.radio.amateur.antenna Subject: Rabbit Ears Question... Date: Thu, 07 Mar 1996 01:42:40 GMT Message-ID: <4hletj$2gq@cloner2.ix.netcom.com> Reply-To: an485930@anon.penet.fi Hey All, is there any way to signifigantly increase the reception of a pair of rabbit ears without buying cable?? I am on the 2nd floor of the house, and reception is ony good on one or two channels. any suggestions??? andrew From lwbyppp@epix.net Mon Mar 11 07:11:47 1996 From: w8jitom@aol.com (W8JI Tom) Newsgroups: rec.radio.amateur.antenna Subject: Re: s meters Date: 10 Mar 1996 10:26:43 -0500 Message-ID: <4husbj$729@newsbf02.news.aol.com> References: <4hug6s$shk@flood.weeg.uiowa.edu> In article <4hug6s$shk@flood.weeg.uiowa.edu>, sabinw@crpl.cedar-rapids.lib.ia.us (Bill W0IYH) writes: > >As I have said before, the Collins guideline was 4 dB per S unit, and I can >find nothing wrong with this. It does not have to be pegged to a noise >level or a signal to noise ratio. The important thing is that if a certain >standard is adopted that everyone uses, then the S-Meter concept is a >useful tool, providing that the rcvr can be accurately calibrated. It is >a simple matter to convert S units to microvolts or dBm of rcvr input. With >an >official F.S. antenna, microvolts per meter could be obtained, if someone >wanted to do that, for example in pattern plotting. > > That makes sense Bill, if every manufacturer would do it. It really isn't an S unit by the old RST definition then, but I don't think anyone uses the real definition correctly anyway. If someone gets an honest report, they'd be hurt! Hi. EVERYONE is 59 or 599. My point was this....many people claim there is a standard of 6 dB per S unit, but there is no "standard". People "pop up" right away with that number, and that incorrect value is even in an answer in the amateur license question pool. But in real life the 6 dB/S unit number is NEVER used as a standard. Currently the ONLY definition of S units is in the RST system, and that would be based on the sound to the operator (S/N ratio), not receiver input voltage. We could have two different definitions of S, like we do many other things in electronics. But we can't get stand ALC response times and interfaces from radio manufacturers, heck...they can't even get CW weight or timing correct! Good luck on meter calibration ! Since Collins (and Drake) left the market, there are no market leaders setting a standard for others to emulate. Personally, I'd like to see ALC, CW timing, control pin outs and voltages, and other things corrected first. They're more important than a relative strength indicator. 73 Tom From lwbyppp@epix.net Mon Mar 11 07:11:48 1996 From: w7el@teleport.com (Roy Lewallen) Newsgroups: rec.radio.amateur.antenna Subject: Re: S Units Date: Sat, 09 Mar 96 07:24:00 GMT Message-ID: <4hrbkn$otj@nadine.teleport.com> References: <313f59d1.156104484@news.comox.island.net> <4holsp$rdn@newsbf02.news.aol.com> <1996Mar8.220310.26984@ke4zv.atl.ga.us> In article <1996Mar8.220310.26984@ke4zv.atl.ga.us>, gary@ke4zv.atl.ga.us (Gary Coffman) wrote: >Receiving antennas, however, present a different problem. Obviously, >some antennas will capture more signal than others, so the signal >strength at the receiver input terminals won't be an absolute measure >of the field strength of the distant station. To get that, you need >a meter calibrated in uV/m, thus including the antenna as part of >the measuring system. That would have to be calibrated on a site by >site basis. Worse than that -- the factor relating terminal signal strength to field strength varies with direction, both in azimuth and elevation. In fact, a plot of this factor is the "antenna pattern". (As I know you know well, Gary. Just wanted to avoid letting folks get misled.) Roy Lewallen, W7EL From lwbyppp@epix.net Mon Mar 11 07:11:50 1996 Newsgroups: rec.radio.amateur.antenna From: gary@ke4zv.atl.ga.us (Gary Coffman) Subject: Re: S Units Message-ID: <1996Mar9.183412.1098@ke4zv.atl.ga.us> Reply-To: gary@ke4zv.atl.ga.us (Gary Coffman) References: <313f59d1.156104484@news.comox.island.net> <4holsp$rdn@newsbf02.news.aol.com> <1996Mar8.220310.26984@ke4zv.atl.ga.us> <4hrbkn$otj@nadine.teleport.com> Date: Sat, 9 Mar 1996 18:34:12 GMT In article <4hrbkn$otj@nadine.teleport.com> w7el@teleport.com (Roy Lewallen) w rites: >In article <1996Mar8.220310.26984@ke4zv.atl.ga.us>, > gary@ke4zv.atl.ga.us (Gary Coffman) wrote: > >>Receiving antennas, however, present a different problem. Obviously, >>some antennas will capture more signal than others, so the signal >>strength at the receiver input terminals won't be an absolute measure >>of the field strength of the distant station. To get that, you need >>a meter calibrated in uV/m, thus including the antenna as part of >>the measuring system. That would have to be calibrated on a site by >>site basis. > >Worse than that -- the factor relating terminal signal strength to field >strength varies with direction, both in azimuth and elevation. In fact, a >plot of this factor is the "antenna pattern". (As I know you know well, >Gary. Just wanted to avoid letting folks get misled.) Right Roy, and it may be this pattern that a transmitting station is trying to measure (or at least get a relative shape factor for) when asking for S reports. And unfortunately, unless he has an isotropic reference antenna that he can switch back and forth with the unknown antenna, he's not going to be able to do that precisely. Since I haven't seen many off the shelf isotropic antennas advertised in QST, this may present a difficult challenge. A reference dipole or reference vertical can be of some use, of course, but unless you know the characteristics of the receiving antenna, and the calibration of the S units on the distant receiver, it still isn't much help. But here is where standard S units can be of some value. That removes one unknown from the equation. If in addition the distant receiving station is using a more or less standard dipole, vertical, or well documented commercial yagi design, then you can start to get a fairly close approximation of the information you need. They all need to work together, however. If one known is converted to an unknown, your level of uncertainty rises. If too many knowns become unknowns, your level of uncertainty rises without bound. We can hope to eliminate one unknown here by agreeing on a standard S unit step and a standard S unit reference level. The old S9=50uV at the receiver input terminals, and each S step being a 6 db decrement from that reference, is a good starting point. We should encourage commercial manufacturers to adhere to that standard (as some did in the past). It won't solve all our signal reporting problems, but it does eliminate one unknown from the equation. An S scale with no reference value and no standard step size is *worthless* to us. If every receiving station has a different reference value (unknown) and a different step size (also unknown) then S unit reports are of no use to us at all. But assuming a standard S scale, and if the receiving station additionally knows the characteristics of his receiving antenna, so that he can give a uV/m reading with some confidence, we're more than halfway home. The only real unknown we have to solve then is path loss in order for us to be able to calculate our transmitting antenna's behavior (ERP) in that direction. (Knowing path loss may not be an easy task, but we can turn things around by knowing our transmit ERP instead, then we can calculate the pass loss, which is a useful thing to know in any event.) Gary -- Gary Coffman KE4ZV | You make it, | Due to provider problems Destructive Testing Systems | we break it. | with previous uucp address es 534 Shannon Way | Guaranteed! | Email to ke4zv@radio.org Lawrenceville, GA 30244 | | From lwbyppp@epix.net Mon Mar 11 07:11:52 1996 Newsgroups: rec.radio.amateur.antenna From: gary@ke4zv.atl.ga.us (Gary Coffman) Subject: Re: S Units Message-ID: <1996Mar8.220310.26984@ke4zv.atl.ga.us> Reply-To: gary@ke4zv.atl.ga.us (Gary Coffman) References: <313f59d1.156104484@news.comox.island.net> <4holsp$rdn@newsbf02.news.aol.com> Date: Fri, 8 Mar 1996 22:03:10 GMT In article <4holsp$rdn@newsbf02.news.aol.com> w8jitom@aol.com (W8JI Tom) writ es: >How could an S unit standard compensate for different RX antennas, site >noise, and even receiver BW (since that affects S/N ratios as well as >noise voltage). Site noise and receiver bandwidth should not affect S meter readings, since S readings are a measure of the signal strength at the receiver *input terminal* only. Those factors will certainly affect SNR, but that's not what S meters purport to measure. (Note: of course a local noise level stronger than the signal will give a meaningless reading since the S meter reading will be the peak noise voltage, not the peak signal voltage in that case.) Receiving antennas, however, present a different problem. Obviously, some antennas will capture more signal than others, so the signal strength at the receiver input terminals won't be an absolute measure of the field strength of the distant station. To get that, you need a meter calibrated in uV/m, thus including the antenna as part of the measuring system. That would have to be calibrated on a site by site basis. >I agree. Why not abolish S units totally and just have a dB scale that can >be adjusted to zero dB for the noise floor at that moment. That wouldn't >tell the other guy what his FS really is, but it would give him an idea of >the S/N ratio and any change when he made a quick test. Yeah, that's useful. However, the local noise level may fluctuate, and so the readings would have to be taken in rapid succession to have much meaning. With a "standard" S unit scale, readings taken day by day and month by month will still have relative value. In other words, if what you want to determine how your signal strength changes over a particular path over a period of time, having a reporting scale referenced to an objective uV number at the distant receiving station is useful, even if it can't be back translated into an absolute field strength measurement or cross correlated to a SNR value without knowing the S reading of the local receiver noise and the bandwidth of the local receiver too. But regardless of whether S9 is defined as 50 uV at the receiver input terminals or some other number, the important thing is that each S unit be a well defined *change* in signal strength. That way a relative set of readings done in cooperation with one station will have meaning in regard to another relative set of measurements made with another station, IE say you have two antennas you want to compare in respect to their performance to a number of different locations, it would be useful to know that when station X says they are 2 S units different that it means the same thing as when station Y tells you they are 2 S units different. The absolute S reading may be meaningless, but the relative readings should be meaningful. They can't be, however, if everyone's receiver uses a different step between S units. 6db per step is a useful size, and with S9 equal to 50 uV, the range from S1 to S9 covers the range from about the receiver MDS to a good strong signal for the majority of HF receivers. S0 should obviously mean "I can't hear you" even when band noise is zero, because the receiver noise overwhelms you. Note: in some cases, S9 might mean "I can't hear you", but it will be because *external* noise sources are overwhelming the signal, *not* because the signal is weak. Gary -- Gary Coffman KE4ZV | You make it, | Due to provider problems Destructive Testing Systems | we break it. | with previous uucp address es 534 Shannon Way | Guaranteed! | Email to ke4zv@radio.org Lawrenceville, GA 30244 | | From lwbyppp@epix.net Mon Mar 11 07:11:53 1996 From: tmaldred@mail.comox.island.net (Thomas M. Alldread) Newsgroups: rec.radio.amateur.antenna Subject: SALE: MFJ202B HF ANT NOISE BRDG Date: Sun, 03 Mar 1996 15:55:54 GMT Message-ID: <31377be0.22274394@news.comox.island.net> Greetings: I have an MFJ-202B HF antenna bridge for sale that is in good condition with manual. It is a current model so please check out the new price. Asking $50 Cdn or $40 U.S.A. funds plus shipping. Tel (604)337-5577 or e-mail. 73 de VE7TMA Very Best Regards: Thomas M. Alldread E-mail: tmaldred@mail.comox.island.net packet radio: VE7TMA@VE7KGW.#NVI.BC.CAN.NA Very Best Regards: Thomas M. Alldread E-mail: tmaldred@mail.comox.island.net packet radio: VE7TMA@VE7KGW.#NVI.BC.CAN.NA From lwbyppp@epix.net Mon Mar 11 07:11:53 1996 From: tmaldred@mail.comox.island.net (Thomas M. Alldread) Newsgroups: rec.radio.amateur.antenna Subject: SALE: MFJ204B HF ANT BRDG Date: Sun, 03 Mar 1996 15:55:51 GMT Message-ID: <31377b75.22166631@news.comox.island.net> Greetings: I have an MFJ-204B antenna bridge for sale that is in very good condition packed with bubble wrap in the original box and is complete with the manual and Duracell battery. Price is $65.00 Cdn or $50.00 USA plus shipping. It is a current model and is listed for $139,95 plus taxes in a Vancouver, BC amateur gear supplier's catalog. Tel (604)337-5577 or e-mail. 73 de VE7TMA Very Best Regards: Thomas M. Alldread E-mail: tmaldred@mail.comox.island.net packet radio: VE7TMA@VE7KGW.#NVI.BC.CAN.NA Very Best Regards: Thomas M. Alldread E-mail: tmaldred@mail.comox.island.net packet radio: VE7TMA@VE7KGW.#NVI.BC.CAN.NA From lwbyppp@epix.net Mon Mar 11 07:11:54 1996 From: "Rick, AA8VQ" Newsgroups: rec.radio.amateur.antenna Subject: Searching for a good dual band mobile antenna Date: 6 Mar 1996 16:42:55 GMT Message-ID: <4hkfaf$7r9@s2.GANet.NET> I've been upgrading the mobile radio system and have aquired a Yaesu FT-8500. I want a good dual band antenna, but don't know much about the "track record" on the Maldo, Diamo nd and Comet antennas. These are ones I'm considering. Your thoughts, good and bad are en couraged. With the cost of one of these thigs being rather high, I'd like to like I'm getting my money's worth. I'm also looking the Premier line as well. Thanks From lwbyppp@epix.net Mon Mar 11 07:11:55 1996 From: dsmith@nlnet.nf.ca (David Smith) Newsgroups: rec.radio.amateur.antenna Subject: Re: shuttle communication on 2 meter Date: 8 Mar 1996 14:56:50 GMT Message-ID: <4hphri$rc8@coranto.ucs.mun.ca> References: <00001fea+0000208c@msn.com> <4gqtvh$dpl@news.fwi.com> <4h2pq6$jav@chnews.ch.intel.com> <4hf150$cc7@tesla.netline.net> I've connected with the packet station on MIR with 5 W and a J-pole. David Smith, VO1DMS From lwbyppp@epix.net Mon Mar 11 07:11:56 1996 From: n5zgt@swcp.com (Brian Mileshosky, N5ZGT) Newsgroups: rec.radio.amateur.antenna Subject: Re: shuttle communication on 2 meter Date: Sun, 10 Mar 1996 16:34:42 GMT Message-ID: <4hv41k$rg4@sloth.swcp.com> References: <00001fea+0000208c@msn.com> <4gqtvh$dpl@news.fwi.com> <4h2pq6$jav@chnews.ch.intel.com> Reply-To: n5zgt@swcp.com tom_boza@ccm.ch.intel.com (WB7ASR) wrote: >Unless you have the "BIG" station, forget about working the shuttle. >They only talk with pre-determined scheduled contacts (schools), or >stations with the loudest signals ( EME arrays with 1KW amps). When >their above your horizon, there are about 200+ stations on the average >all calling them at the same time you are. The BIG signal will win!!! >WB7ASR... Why does everybody need a HUGE amount of power, and a complicated antenna? Sure there are 200+ stations calling them at the same time I am, but hey, if everybody HAS to have a superstation like the example above, why have I always been able to contact the shuttle on voice with only a 3/4 wave groundplane up 40 feet, and a 50 watt mobile rig? Go figure... Best of 73, Brian, N5ZGT... ________________________________________________________________________ Boy Scouts of America Amateur Radio J.A.S.M. - Troop 41 N5ZGT Albuquerque, NM Packet: N5ZGT @ KC5IZT.ALBQ.NM.USA.NA Great Southwest Council Internet: n5zgt@swcp.com O.A. Lodge 66 _______________________________________________________________________ From lwbyppp@epix.net Mon Mar 11 07:11:57 1996 Newsgroups: rec.radio.amateur.antenna From: G.Lewis@astro.cf.ac.uk (Gareth Lewis) Subject: Simple FM arial plans-where can I find them ? Message-ID: Date: Sun, 10 Mar 1996 18:20:24 GMT Reply-To: G.Lewis@astro.cf.ac.uk (sorry for the newbie post) I want to build a small-ish outdoor antenna for fm (80-108 Mhz) Anyone to the rescue ? I haven't found any web pages or FAQ's yet, there must be a few sites about somewhere. -- cheers, Gareth. ------------------------------------------------------------------------------ Gareth Wyn Lewis | Email : G.Lewis@astro.cf.ac.uk Department of Physics and Astronomy, | Phone : +44 (0)1222 874000 ext 5316 University of Wales,College Cardiff, | Fax : +44 (0)1222 874056 P.O. Box 913, | WWW : http:/www.astro.cf.ac.uk/ Cardiff | Home page : (/pub/Gareth.Lewis) CF2 3YB. | ------------------------------------------------------------------------------ From lwbyppp@epix.net Mon Mar 11 07:11:58 1996 Newsgroups: rec.radio.amateur.antenna From: choffman@pelican.davlin.net (Charles Hoffman) Subject: Re: Slot Antenna Plans? Message-ID: Date: Thu, 7 Mar 1996 21:05:53 GMT Reply-To: choffman @pelican.davlin.net References: <4hlpt2$apq@spot.yknet.yk.ca> Contact the OM himself, Ralph O. Robinson, WA3YEE, retired from Johns Hopkins Applied Physics Labs., now living on a ranch between Kerrville and Harper Texas. Ref. 1) U.S. Patent No. 2908000; 2) Johns Hopkins University/APLL Bumblebee Series Report No. 118, "The Design and Application of Notch Excited Antennas for Aerodynamic Surfaces" (Available Natl Tech Info Serv, Springfield, Va 22161, Accession Nr AD85887. 73 K5SBU Brian Butler wrote: >Does anyone know where I may find plans for 900MHz, 1200MHz, and >higher freq. slot antennas? >Thanks >Brian >VY1BB From lwbyppp@epix.net Mon Mar 11 07:11:59 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: Small gardens: antenna? Date: Sat, 09 Mar 96 15:44:31 GMT Message-ID: <4hs97t$bkh@crash.microserve.net> References: <826360734.19900@drmoody.demon.co.uk> darrellm@drmoody.demon.co.uk (Darrell Moody) wrote: >I'm looking for a small, non-vertical antenna for the higher HF bands >(20m and up). QTH here is a typical modern UK house: tiny garden >(30ft >square), surrounded by houses and radio-unfriendly neighbours! >I've tried various wire designs but they just seem to cause TVI >and/or don't work. Are minibeams any good? Suggestions welcomed. Which wire designs have you tried? A shortened, center-fed dipole fed with open wire line and a balanced tuner (not a balun) should not cause TVI or undue RFI. 73, Jack WB3U From lwbyppp@epix.net Mon Mar 11 07:11:59 1996 From: darrellm@drmoody.demon.co.uk (Darrell Moody) Newsgroups: rec.radio.amateur.antenna Subject: Small gardens: antenna? Date: Sat, 09 Mar 1996 08:42:31 GMT Message-ID: <826360734.19900@drmoody.demon.co.uk> I'm looking for a small, non-vertical antenna for the higher HF bands (20m and up). QTH here is a typical modern UK house: tiny garden (30ft square), surrounded by houses and radio-unfriendly neighbours! I've tried various wire designs but they just seem to cause TVI and/or don't work. Are minibeams any good? Suggestions welcomed. -------------------------------------- Darrell G0HVQ UKSMG#353 Loc IO81VV darrellm@drmoody.demon.co.uk -------------------------------------- From lwbyppp@epix.net Mon Mar 11 07:12:01 1996 From: TSMITH@fibusa.COM (Tim Smith) Newsgroups: rec.radio.amateur.antenna Subject: RE: TAI-CHI MASTER - 3/13 - PC THEATER Date: 6 Mar 96 19:37:00 GMT Message-ID: <313DEC4B@ipnovell.fibusa.com> does anyone know where this junk comes from and how to stop it? ---------- From: mailfail To: genweb; global_data_storage; glokor; glomex; go-players; goldenkey; gra.info; gsareps; gwis; habitatlink; ham-am; ham-amtor; ham-ant; ham-atv; ham-bsd; ham-digital-voice; ham-digital; ham-dxing; ham-eme; ham-equip; ham-exotic-modes; ham-fax; ham-fx; ham-homebrew; ham-mods; ham-morse; ham-nocode; ham-packet; ham-policy; ham-radio; ham-rtty; ham-slowscan; ham-space; ham-spread; ham-ssb; ham-uwave; ham-vhf-uhf; hem-onc_seminars; high-tc; hosttables; hott-list; hp-users; htcucsd; htgsd Subject: TAI-CHI MASTER - 3/13 - PC THEATER Date: Wednesday, March 06, 1996 7:17AM ATTENTION FILM-GOERS!: *************************************************** Don't Miss Two of Hong Kong's Most Exciting Stars in One of the Greatest Martial Arts Films of All Time!!! *************************************************** ________________________ | | | THE TAI-CHI MASTER | | | | Directed by Yuen Woo Ping | | Hong Kong, 1993 | | | | Starring: **JET LI** and | | **MICHELLE KHAN** | |________________________| ---------------------------------------- WEDNESDAY, MARCH 13 at the PRICE CENTER THEATER! ---------------------------------------- _________________________ | | | SHOWTIMES: 5:30 / 8:00 / 10:15 | |________________________ | ******************************** GENERAL ADMISSION: $2 TICKETS ON SALE NOW AT THE PRICE CENTER BOX OFFICE ******************************** WIN FABULOUS DOOR PRIZES!!! Enter and WIN the GRAND PRIZE in our TRIVIA RAFFLE!!! From lwbyppp@epix.net Mon Mar 11 07:12:02 1996 From: kg9cc@iaonline.com (Jim Rowley) Newsgroups: rec.radio.amateur.antenna Subject: Tower Guy Spacing Date: Fri, 08 Mar 1996 14:07:51 GMT Message-ID: <4hpihd$r8i@kelly.iaonline.com> Hello all. This is my first time posting so I hope I do it right. I remember reading somewhere that if you are limited on space that you can reduce the distance from the tower base to guy anchor point from the recomended 80% of tower height to something like 50% by going to 4 guys spaced 90 degrees. Rohn shows this in their catalog but only for the foldover towers. I plan to install 70ft of Rohn 45G and would like to space the guy anchors between 35 and 40 ft from the base. Anyone out there know about this or has used this method? Thanks and 73 Jim, KG9CC From lwbyppp@epix.net Mon Mar 11 07:12:04 1996 From: <102452.2315@compuserve.com> Newsgroups: rec.radio.amateur.antenna Subject: USA QSL BUREAU Date: 10 Mar 1996 12:40:37 GMT Message-ID: <4huik5$96l@dub-news-svc-3.compuserve.com> Keywords: us buro usa buro usburo usaburo usabureau * * * * * * * A T T E N T I O N A L L H A M S * * * * * * * NOW SEND "QSL VIA USBURO" ON THE AIR! USA QSL BUREAU FOR ALL YOUR DOMESTIC QSL CARDS, ALL 10 DISTRICTS, TERRITORIES AND TRUSTEESHIPS OF THE U.S.A. SAVE $$$ ON POSTAGE-SAVE $$$ ON CALLBOOKS-SAVE $$$ ON CD-ROMS FAST..PROMPT..PROFESSIONAL..SERVICE..FOR HAMS BY HAMS RATES FOR YOUR OUTGOING CARDS; 2 - 10 CARDS $.10 EA. - 10 FOR $1.00 - 50 FOR $4.50 100 FOR $8.00 - OVER 100, $7.00 PER HUNDRED CARDS PLEASE PUT CALLSIGN OF STATION YOU ARE SENDING CARD TO IN THE ADDRESS SECTION (BACK OF CARD) IN 3/4 TO 1 INCH LETTERS! 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OPERATED BY AA1MF & CREW E-MAIL 102452.2315@COMPUSERVE.COM -EOF- From lwbyppp@epix.net Mon Mar 11 07:12:05 1996 From: Michael J Wooding Newsgroups: rec.radio.amateur.antenna Subject: VHF Communications Magazine Date: Wed, 6 Mar 1996 18:45:52 +0000 Distribution: world Message-ID: Hi Folks, For subscribers and interested parties: Issue 1/1996 of VHF Communications is now at the printers and should be shipped by March 30th. For more information on the contents of this issue and on subscribing to the magazine take a look at our Web site: http://www.eolas.co.uk/ag/vhfcomm.htm Thanks and 73 ... Mike Michael J Wooding vhf-comm@g6iqm.demon.co.uk - CompuServe: 100441,377 Web Pages: http://www.eolas.co.uk/ag/vhfcomm.htm (hambits.htm & hamclip.htm) Tel: (0)1788 890365 Fax: (0)1788 891883 KM Publications, 5 Ware Orchard, Barby, Nr.Rugby, CV23 8UF, UK VHF Communications Magazine - Especially Covering VHF, UHF and Microwaves From lwbyppp@epix.net Mon Mar 11 07:12:06 1996 From: atkes@imap1.asu.edu Newsgroups: rec.radio.amateur.antenna Subject: VHF current balun Date: 9 Mar 1996 18:27:18 GMT Message-ID: <4hsii6$1ct@news.asu.edu> A common balun on vhf is the 4:1 1/2 wavelength coaxial balun. Using Roy Lewallen's terminology this would be a voltage balun. In his phased array section in the antenna book, Roy advocates using 1/4 or 3/4 wave sections to force the feedpoint current of antennas to be either in or 180 degrees out of phase. An obvious generalization is to use these sections to make a current balun where the two halves of a balanced antenna are driven 180 degrees out of phase. | 1/4 wavelength | connect ============================--|<-- one side of antenna in |<------ ground parrallel ============================--|<-- other side of antenna 3/4 wavelength | | For the balun input to be 50 ohms, the impedance at the end of each section should be 100 ohms. By using coaxial cable with a characteristic impedance of Z0 you would produce an impedance transorm to Z0^2/100, and the impedance of the driven element would need to be Z0^2/50. This says using 50 ohm, 70 ohm or 100 ohm cable for the balun would make a 1:1, 2:1, or 4:1 balun respectively. The 1:1 balun would probably be most useful and simple to make. The disadvantages that I see are that twice as much cable is used as for a voltage balun, and more cable connections are required. However the connection disadvantage is partly offset by being able to use a T connector for main feedline input feedpoint and a pair of standard connectors at the antenna feedpoint. More cable means more loss and more frequency sensitivity - roughly since it uses a wavelength of cable, you might expect the bandwidth to be half that of a half wavelength voltage balun. In both the voltage and this current balun, to have a swr of 1 in the balun cable, the cable needs to be 100 ohm and you have a 4:1 balun. Here you get a 1:1 balun with 50 ohm cable. Has anyone used this? I have never seen it described, but it would seem to be a natural way to feed quagis where the feedpoint is nearly 50 ohms. Kevin Schmidt, w9cf@ptolemy.la.asu.edu From lwbyppp@epix.net Mon Mar 11 07:12:08 1996 Newsgroups: rec.radio.amateur.antenna From: bart@wb6hqk.ampr.org (Bart Rowlett) Subject: Re: W6KKT VISALIA HF MOBILE ANTENNA "SHOOTOUT" INFO Message-ID: References: <4hc0ac$leq@ns.kern.com> <4hhego$8np@newsbf02.news.aol.com> Date: Sat, 9 Mar 1996 01:09:23 GMT In article <4hhego$8np@newsbf02.news.aol.com>, W8JI Tom wrote: >In article <4hc0ac$leq@ns.kern.com>, Jesse Touhey >writes: > >> >>W6KKT Will be conducting another HF Mobile Antenna System "Shootout" at >>the upcoming Visalia, Calif.DX convention. This event will be held at the > >>U.S Towers factory, Saturday, April 20th, 10:00am. The test frequency >>will be 3995kc. >>So, if you plan to be in the area, join us for fun, food and see how your > >>mobile antenna system "stacks up" against some of the best systems in the > >>country.....73s...Jesse (W6KKT) >> >> > >WHAT are the rules??????? 73 Tom from Atlanta GA. The purpose of the contest is to compare the DX performance of various 75M mobile antenna installations by measuring the ratio of low angle vertically polarized radiation to the power actually delivered to the antenna. Power delivered to the antenna is assumed to be the difference between the measured forward and reverse power indicated with a Bird wattmeter. Radiation is measured by a custom designed field strength meter sensitive only to the horizontal magnetic field existing a couple of hundred yards from the antenna and about eight feet above the ground. The field strength measured is actuall y a combination of the vertically polarized radiated field, the groundwave and the near field remaining at the test distance. Since the antenna heights are all about the same (13.5 feet maximum), it is assumed the near field contribution (corruption) to the measurement is small and about equal from all contestants. Since the antenna heights are very low, only the vertically polarized components are considered useful for DX. An antenna could somehow have a large horizontally polarized component optimized for NVIS and would be just dandy for local mobile use, but wouldn't score well in the test. Power is converted to dB referenced to 50 watts and subtracted from the field strength in dB (arbitrary but stable reference). The resulting values are repeatable to better than .25 dB over several hours and are believed to accuratly compare the various installations but have no absolute significance. Very good correlation has been acheived between the same contestants at different shootouts performed at different venues. The field strength meter has a dynamic range of over 70 dB but has been most accuratly calibrated over the 10 or so dB range encountered during this contest. bart wb6hqk bart@wb6hqk.ampr.org From lwbyppp@epix.net Mon Mar 11 07:12:09 1996 From: tom_boza@ccm.ch.intel.com (WB7ASR) Newsgroups: rec.radio.amateur.antenna Subject: Re: What's your favorite 6mt FM mobile antenna? Date: 8 Mar 1996 17:32:41 GMT Distribution: world Message-ID: <4hpqvp$eer@chnews.ch.intel.com> References: <4gu1e8$fqq@newsbf02.news.aol.com> <31363423.6CFF@trw.com> <4haeb4$ja9@news.paonline.com> Cut down a full size fiberglass 1/4 wave CB wip to 54 inchs. Use a 3/8 inch type mount, any kind, as long as your roof mount it. From lwbyppp@epix.net Mon Mar 11 07:12:10 1996 From: graham@southlin.demon.co.uk (Graham Seale) Newsgroups: rec.radio.amateur.antenna Subject: Re: Why long wire TVI Date: Wed, 06 Mar 1996 08:38:26 GMT Distribution: world Message-ID: <19960306.083826.89@southlin.demon.co.uk> References: <4hhefr$cvb@news.asu.edu> Reply-To: graham@southlin.demon.co.uk In message <4hhefr$cvb@news.asu.edu> CHARLES J. MICHAELS wrote: > > G4wnt said - > Last shot about RF in the house is to debunk the fond belief that the outer > braid of a coax is somehow a "screen" that will "stop nasty RF from getting > out". The braid is actually one half of an unbalanced transmission line! The > *only* condition where it will not radiate is if the cable is feeding a load > equal to its characteristic impedance. Anything else - and the standing wave > currents on the braid will radiate where they are not wanted. > > This is not true. standing waves in a coax do not cause radiation > from the outside of the coax. Except for a very small leakage due to the > woven nature of most coax outer conductors, the currents are confined to > the inner surface of the otu/// outer conductor by skin effect. In most > cases currents on the outside of the outer conductor are due to either > those flowing from the connection to the antenna of the outer conductor > or due to currents induced in the outer condutor by the antenna . > > Charlie, W7XC Hi Charlie Maybe in between postings you missed the exchange between myself and Cecil Moore where we worked this one out. You sure are right that the simple presence of standing waves on a coax is not a cause for radiation - because the forward currents are matched by the returning currents, and hence any near fields they might have made are zero. The trouble is a coax is an unbalanced structure, and so it is difficult to keep the currents equal because the braid couples to the surroundings, but the inner conductor cannot. Even this is no big problem ... until the coax couples as part of the counterpoise of an antenna structure! Then you can have very large unbalanced (common mode) currents. In this case, radiation from coax can be very troublesome. This situation is hard to avoid if the coax is involved in end feeding long wires. The potential for TVI is huge, especially if the coax trails through loft. The easy fix is first to ensure that liberal "grounding" of things in the shack do not upset the principle that all the currents *and* their returns go via the feeder. If this is a coax, then common mode currents can be frustrated by winding a dozen or so turns into the coax. When the feeder is clear of the house, you can make the field counterpoise to a radial system or even a few yards of wire laid on the ground - whatever. Allowing fields generated at the antenna to "go around" the feeder setup and find their convenient counterpoise among house wiring and shack stuff makes the scene very prone to TVI. There is bound to be better wisdom than mine in this group, but the above rationale made sense to me at the time, and I have managed to avoid TVI by using balanced feeders . 73s G4WNT -- Graham Seale From lwbyppp@epix.net Mon Mar 11 07:12:11 1996 From: Listserv@ucsd (Mailing List Processor) Newsgroups: rec.radio.amateur.antenna Subject: Re: your LISTSERV request "help on finding/creating custom? mobile antenna." Date: 7 Mar 96 09:11:33 GMT Message-ID: <199603070911.BAA12083@mail.ucsd.edu> The mailing list "on" could not be found. You may use the INDEX command to get a listing of available mailing lists. From lwbyppp@epix.net Mon Mar 11 07:12:13 1996 From: n6gk@garlic.com Newsgroups: rec.radio.amateur.antenna Subject: Re: } SPIDER HF Antenna - NEED INFO { Date: 9 Mar 1996 04:22:07 GMT Message-ID: <4hr11f$hue@quake.garlic.com> References: <4hih5v$gda@sloth.swcp.com> I've used the Spider antenna for years and really like it for multi-band operation. Over the years I expanded it to cover all bands, 10 - 40, including the WARC bands by adding another "collar" to add 3 more elements. I keep it tuned to the CW portion of each band and then use the tuner in my TS-440 to match if I go to the SSB portion. It works great. Of course, you mentioned 40 and 80. If I was to specialize on those bands only, I probably would go to "monoband" "longjohns" - dedicated single-band antennas, as communications there (especially 80) can be challenging from mobile. (But I've worked plenty of 40M CW DX with the Spider). If you move around a lot, bandwidth is also a consideration and the ease with which you can change frequency (esp. if you have no tuner in your rig). You might also consider the "screwdriver" type antennas, which are also multiband and permit adjustment from within the car (but not the instant band change of the Spider). The service I've received throught the years from Spider has also been outstanding. 73, Greg, N6GK From lwbyppp@epix.net Mon Mar 11 13:52:44 1996 From: jillngus@slip.net (jillngus) Newsgroups: rec.radio.amateur.antenna Subject: Re: } SPIDER HF Antenna - NEED INFO { Date: Wed, 06 Mar 1996 20:18:17 -0700 Message-ID: <4hlk93$6kc@slip.net> References: <4hih5v$gda@sloth.swcp.com> In article <4hih5v$gda@sloth.swcp.com>, n5zgt@swcp.com wrote: > Hello Everybody, > I am really thinking into buying a Spider HF mobile antenna. This > is the 4 band top-loaded HF antenna. I would like to get the following > information regarding this antenna from people wjo have used them. > What do you like about the antenna? What DON'T you like about the > Spider? Is it a good antenna to use mobile? What about at a home QTH? > I'm looking into it primarily for 80 and 40 meters. Is this a good > antenna for these bands? > Also, any other information would be GREATLY appreciated! Thanks! > Best of 73, > Brian, N5ZGT... > > n5zgt@swcp.com > > > > ________________________________________________________________________ > Boy Scouts of America Amateur Radio > J.A.S.M. - Troop 41 N5ZGT > Albuquerque, NM Packet: N5ZGT @ KC5IZT.ALBQ.NM.USA.NA > Great Southwest Council Internet: n5zgt@swcp.com > O.A. Lodge 66 > _______________________________________________________________________ Hi Brian, I bought one about 11 years ago, right after they came out. I had it mobile for 2 or 3 years and loved it. I worked all sorts of DX from the car, probably 30 or 40 countries without really trying. I recently resurrected it and roof mounted it on my condo, complete with radials. It was very disappointing. Although the SWR was okay, I simply didn't hear many people, and no dx at all. I replaced it with an R5 and hear more on 40 now than with the spider, even though the R5 doesn't have 40 meter capability. Good luck..Gus, WA6WBC From lwbyppp@epix.net Mon Mar 11 13:52:46 1996 From: Bill Levey Newsgroups: rec.radio.amateur.antenna Subject: Re: QUAD QUESTIONS... Date: Fri, 08 Mar 1996 15:29:53 -0600 Message-ID: <3140A6D1.21B@bro.net> References: <4hjufs$jii@linet06.li.net> Keith Smith wrote: > I'm looking for some info on quads...Should I buy or make my own?? Quads are relatively easy to make but often difficult to tune for optimum performance. Quality components are also somewhat tough to find. If you are a 'tinkerer' and don't mind occasional frustration sprinkled with delightful success, I'd recommend you *go for it*. >Are they worth making ...?? Opinion on quad performance ranges from 'absolutely nothing compares' to 'about the same as a yagi and more difficult to maintain' ... and everything in between. Serious DX'ers tend to be more unified in their praise of quad systems, observing the quiet nature of a full-wave antenna and the lower RF launch angle. The only way to know for sure if 'they are worth making' is to give them a try personally. And now a self-serving plug: My company is a quad manufacturer and a resource should you prefer to investigate commercially-available quads. (We focus on VHF and UHF systems primarily.) Information may be found on our web site at http://bro.net/aae or by our email auto-responder. Send your info request to quadinfo@bro.net for an immediate reply. 73! Bill Levey - WA4FAT Bandmaster Quads From lwbyppp@epix.net Mon Mar 11 13:52:47 1996 From: sabinw@crpl.cedar-rapids.lib.ia.us (Bill W0IYH) Newsgroups: rec.radio.amateur.antenna Subject: s meters Date: 10 Mar 1996 11:59:24 GMT Distribution: world Message-ID: <4hug6s$shk@flood.weeg.uiowa.edu> Reply-To: SABINW@crpl.cedar-rapids.lib.ia.us The purpose of an S Meter is to tell the strength, in microvolts or dBm, of the signal level at the antenna input. This requires a known value of receiver gain and an accurate AGC. If every rcvr has the same calibration, then meaningful comparisons can be made between different locations, and also at a single location when doing antenna comparisons. An accurate rcvr is one element in a bonafide field strength measurement setup. It can accurately perform comparative measurements that are reliable over long periods of time. As I have said before, the Collins guideline was 4 dB per S unit, and I can find nothing wrong with this. It does not have to be pegged to a noise level or a signal to noise ratio. The important thing is that if a certain standard is adopted that everyone uses, then the S-Meter concept is a useful tool, providing that the rcvr can be accurately calibrated. It is a simple matter to convert S units to microvolts or dBm of rcvr input. With an official F.S. antenna, microvolts per meter could be obtained, if someone wanted to do that, for example in pattern plotting. The idea of an internal S9 noise reference that can be used to check rcvr gain would be reassuring. The automatic calibration procedure can be programmed into a "smart" rcvr and would take a second or two to complete. Official field strength rcvrs always contain self-calibrating hardware. And if I tell someone that he is S6 at my location, I have given some useful information about the **Communication Channel** performance. From lwbyppp@epix.net Mon Mar 11 13:52:49 1996 From: guenter.koellner@oen.siemens.DE (Koellner, Guenter) Newsgroups: rec.radio.amateur.antenna Subject: Subject: construction plan for a 2m beam Date: 11 Mar 96 16:27:00 GMT Message-ID: <31445B93@SmtpGate.Oen1.Oen.Siemens.De> Hello, for all bands 6m, 144MHz, 432MHz and 1296MHz I prefer to use the the DJ9BV designed Yagis: 144MHz in DUBUS 1/90 432MHz in DUBUS 2/91 1296MHz in DUBUS 2/94 50MHz in DUBUS ?/95 (later releases...) A 144MHz Yagi can be built easily, I will give the data for a 1.8 lambda (3.8m) long yagi here. Other versions up to 10m boomlength can be read from the article itself. All articles are available on request from me. All measures in mm! Length Position R 1053 0 (two reflectors spaced 600 between) DE 990 360 (990 outside length, 66 outside width, opening 15) (8mm diam. tube, use a lambda/2 balun for feeding) D1 950 525 D2 940 900 D3 930 1350 D4 920 1875 D5 915 2460 D6 910 3090 (For shorter versions D6 and D7 can be obtained) D7 905 3750 The elements are 4mm dia and isolated mounted. Some nylon rivets or nylon screws were successfully used for this. This has the advantage that corrossion between the elements and the boom never takes effect on the electrical data. Boom is a square 20x20 aluminium. This can easily be drilled. vy 73, Guenter, DL4MEA@DB0KCP.#BAY.DEU.EU (AX.25) dl4mea@amsat.org (Internet) http://www.scn.de/~koellner (WWW) From lwbyppp@epix.net Sat Mar 16 15:20:50 1996 From: Cecil Moore Newsgroups: rec.radio.amateur.antenna Subject: Re: "floating" the output of a tuner. Date: Sun, 10 Mar 96 01:33:40 -0500 Message-ID: References: <4hsvn5$a51@news.cis.okstate.edu> COUGER GORDON writes: >Somewhere I read that a tuner doesn't need a balan for balanced loads >if the tuner was allowed to "float". I purchased a tuner almost Hi Gordon, we beat this one to death last year. As I remember, putting an unbalanced tuner in a balanced line unbalances the currents causing feedline radiation and doesn't protect the balun from common mode currents. Balanced tuners are much better. Could yours be modified for balanced operation? 73, Cecil, KG7BK, OOTC From lwbyppp@epix.net Sat Mar 16 15:20:51 1996 From: tomb@lsid.hp.com (Tom Bruhns) Newsgroups: rec.radio.amateur.antenna Subject: Re: "floating" the output of a tuner. Date: 11 Mar 1996 16:54:39 GMT Message-ID: <4i1lsf$6vj@hpcvsnz.cv.hp.com> References: <4hsvn5$a51@news.cis.okstate.edu> COUGER GORDON (gcouger@master.ceat.okstate.edu) wrote: : Somewhere I read that a tuner doesn't need a balan for balanced loads : if the tuner was allowed to "float". I purchased a tuner almost : compleatly isolated from the case and enclosure. All that is conected are : the ground side of the coax fittings. Depends on the configuration of the tuner. As Gary C pointed out, a "T" (or for that matter any configuration with one terminal common to both input and output) is "unbalanced". If you perfectly floated the source as well as the tuner, the output could be "balanced". But if you use a link-coupled tuner, it's easy to configure the output side to be balanced and the input side to be unbalanced. And you can just as well have the output side unbalanced, if that's what you want. Changes in where you connect the output let such a tuner match a very wide range of impedances with potentially good efficiency. -- Cheers, Tom tomb@lsid.hp.com From lwbyppp@epix.net Sat Mar 16 15:20:52 1996 From: w8jitom@aol.com (W8JI Tom) Newsgroups: rec.radio.amateur.antenna Subject: Re: "floating" the output of a tuner. Date: 11 Mar 1996 12:11:02 -0500 Message-ID: <4i1mr6$cd9@newsbf02.news.aol.com> References: In article , Cecil Moore writes: >Hi Gordon, we beat this one to death last year. As I remember, >putting an unbalanced tuner in a balanced line unbalances the >currents causing feedline radiation and doesn't protect the >balun from common mode currents. Balanced tuners are much >better. Could yours be modified for balanced operation? > >73, Cecil, KG7BK, OOTC Hi Cecil, Actually we didn't beat this to death enough! Even a balanced tuner won't usually or predictibly change the common mode impedance presented to the balun! It may make it better or worse, but usually the change is not large at all. If the balanced tuner is referenced to ground (becoming a balanced voltage source) then it helps the stresss on the balun, but not if the balanced circuit floats at the common point. Unfortunately the floating system is the best one for balance under real world load conditions. So 'ere we go again.... Moving the balun just doesn't do everything claimed. 73 Tom From lwbyppp@epix.net Sat Mar 16 15:20:53 1996 From: w8jitom@aol.com (W8JI Tom) Newsgroups: rec.radio.amateur.antenna Subject: Re: "floating" the output of a tuner. Date: 12 Mar 1996 01:59:50 -0500 Message-ID: <4i37d6$a8b@newsbf02.news.aol.com> References: <4hsvn5$a51@news.cis.okstate.edu> In article <4hsvn5$a51@news.cis.okstate.edu>, gcouger@master.ceat.okstate.edu (COUGER GORDON) writes: >Somewhere I read that a tuner doesn't need a balan for balanced loads >if the tuner was allowed to "float". I purchased a tuner almost >compleatly isolated from the case and enclosure. All that is conected are >the ground side of the coax fittings. > >My plan is to install a plexiglass mount for the coax fittings and removing >the ground from the case and chasis and tying the grounds from both >coax fittings togeather. I will of courese ground the case. > >Has anyone done this before and can anyone offer any insight? > >Please don't turn this in to a religous argument about baluns. > >Thanks >Gordon AB5DG Hi Gordon, Moving a choke balun to the input of any tuner does little to improve balance. The common mode currents remain the same. It does relax the differential mode stress on the balun, but most choke baluns take that very well anyway...it's usually not a consideration unless you run really high power and/or very high load impedances ! In my opinion (and I spent a long time measuring the results) moving the balun isn't worth the effort. Very little, if anything, is gained for all the effort. 73 Tom From lwbyppp@epix.net Sat Mar 16 15:20:54 1996 From: BColenso@aol.COM Newsgroups: rec.radio.amateur.antenna Subject: (none) Date: 11 Mar 96 02:31:32 GMT Message-ID: <199603110231.VAA18370@emout05.mail.aol.com> erested, there isl be a newly discovered comet that should put on quite a show in a few weeks. It is called the Hyakutake Comet (after the Japanise gentleman who discovered it), and will best be seen in the northern skies between the Big and Little Dippers between March 20-27th, and will be between 2 and 4 times the size of a full moon. It will be only 9 million miles from Earth, 1/10 the distance from the Earth and the Sun. There is a really cool WEB sight about comet sightings. Check it out!! HTTP://ENCKE.JPL.NASA.GOV/ Bob KD8WU From lwbyppp@epix.net Sat Mar 16 15:20:55 1996 From: st11@ita.pwr.wroc.PL (Paul) Newsgroups: rec.radio.amateur.antenna Subject: (none) Date: 11 Mar 96 17:00:57 GMT Message-ID: <199603111701.JAA05697@UCSD.EDU> subscribe From lwbyppp@epix.net Sat Mar 16 15:20:56 1996 From: /PN=Scott.C.Werling/O=wallace/PRMD=iadps/ADMD=attmail/C=us/@safe.ia.GOV Newsgroups: rec.radio.amateur.antenna Subject: (none) Date: 11 Mar 96 19:31:39 GMT Message-ID: <199603111931.NAA00531@outpost.safe.ia.gov> >From /PN=Scott.C.Werling/O=wallace/PRMD=iadps/ADMD=attmail/C=us/ Mon Mar 11 1 3:31:10 CST 1996 remote from osiint.safe.ia.gov Date: 11 Mar 1996 13:29:09 -0600 X400-Trace: US*ATTMAIL*IADPS arrival 11 Mar 1996 13:29:09 -0600 action Relayed From: /PN=Scott.C.Werling/O=wallace/PRMD=iadps/ADMD=attmail/C=us/@osiint.safe. ia.gov To: "/RFC-822=ham-ant(a)UCSD.EDU/OU=OSI-INTERNET/O=WALLACE/PRMD=IADPS/ADMD=ATT MAIL/C=US/"@osiint.safe.ia.gov Subject: Ok Importance: normal Autoforwarded: FALSE Message-Id: P1-Message-Id: US*ATTMAIL*IADPS;IDPS3550 werl0311132640aa UA-Content-Id: werl0311132640aa P1-Content-Type: P2 Priority: normal Received: from osiint.safe.ia.gov by iadpshub.safe.ia.gov; Mon, 11 Mar 1996 13 :31 CST Content-Type: text Content-Length: 156 I'm not getting the digest version any more. In fact I'm receiving nothing at all from the list. Is it still going? Scott werling@safe.ia.gov From lwbyppp@epix.net Sat Mar 16 15:20:57 1996 From: Erik Finskas OH2LAK Newsgroups: rec.radio.amateur.antenna Subject: 23cm vertical antennas Date: Mon, 11 Mar 1996 17:52:57 +0000 Message-ID: <31446879.4E35@ee.port.ac.uk> I am looking for building instructions or modification information for 23cm vertical antennas. Collinear would be the best to archieve some gain, because there is a height limit. Anyone modified 900MHz cellular antennas for 23cm? Erik -- Erik Finskas G/OH2LAK Email Finskase@ee.port.ac.uk Lakki@clinet.fi University of Portsmouth, UK Department of Electric and Electronic Engineering From lwbyppp@epix.net Sat Mar 16 15:20:58 1996 From: Cecil Moore Newsgroups: rec.radio.amateur.antenna Subject: Re: 4:1 or 9:1, which is better? Date: 11 Mar 1996 16:47:08 GMT Distribution: world Message-ID: <4i1lec$9vl@chnews.ch.intel.com> References: <4hrgu7$9tn@crash.microserve.net> <4hsd2h$7pt@newsbf02.news.aol.com> w8jitom@aol.com (W8JI Tom) wrote: >Why a 4:1 balun is used on an unmatched line is beyond me! It's gotta be >the worse thing in the world (oops, there's the 9:1...that'd be worse). Hi Tom, If I install series/parallel caps/coils/stubs at the point on the ladder-line to achieve a Z0-match, I'm left with a 300 ohm or 450 ohm resistive load for the balun. If I use a 1:1 balun, I have either a 6:1 or 9:1 50 ohm SWR. For those boundary conditions, do you think a 6:1 or 9:1 balun would be more efficient than a 1:1 balun/choke especially since a tuner would be required only because one chose to use a 1:1 balun? It's not a trick question. Simply put, is a 6:1 balun without a 50 ohm tuner more or less efficient than a 1:1 balun with a 50 ohm tuner? 73, Cecil, KG7BK, OOTC (not speaking for my employer) From lwbyppp@epix.net Sat Mar 16 15:20:59 1996 From: Rick Wilson Newsgroups: rec.radio.amateur.antenna Subject: >"floating" the output of a tuner Date: 12 Mar 1996 20:11:15 GMT Message-ID: <4i4lp3$bhd@babylon5.glenqcy.glenayre.com> Most of the tuners on the market that boast of a balanced output, use a low-impedance balun to do the transformation. The output of such a device is o nly balanced when the Z is low (less than 150 ohms or so) and there is little reac tance. The so-called balanced load must also be truly balanced, as the balun can't compensate for uneven amounts of C to ground. A truly balanced output involves one of those hard-to-build Antenna Handbook tuners that use lots of plug-in, split-winding coils with caps that are isolated from ground on both sides. 600-ohm line that is driven by a low-Z balun is feeding the antenna network in the common mode in most cases. -- Rick Wilson | e-mail: rdw@glenqcy.glenayre.com fax 217 221 6259 | voice 217 221 6137 | ham call W0KT se habla espan~ol | ich spreche deutsch | si parla italiano From lwbyppp@epix.net Sat Mar 16 15:20:59 1996 From: john@chief.com (76lt XO Dweebs Of Death) Newsgroups: rec.radio.amateur.antenna Subject: A Question On a 2m Vertical Antenna Date: Mon, 11 Mar 1996 15:43:12 MST Message-ID: Hi guys I have just got started in HAM radio and I a simple problem I need to find the answer too. I have a 2 meter vertical antenna that needs a ground. Do I put the ground on the radiating part of the antenna(there seems to be a bolt there for it) or do I pu it on the baseof the anttena which has the radials connected to it? Any help would be appreciated because I don't want to xap my radio with static electrisity. John From lwbyppp@epix.net Sat Mar 16 15:21:01 1996 From: gherbst@msn.com Newsgroups: rec.radio.amateur.space,rec.radio.amateur.misc,rec.radio.amateur.homebrew,rec.radio.amateur.equipment,rec.radio.amateur.antenna Subject: Re: Announsing: Technology Patent Available For Purchase Date: Mon, 11 Mar 96 09:11:20 PDT Message-ID: References: <4hdlvj$kvv@sun.sirius.com> <4hfqtn$6kb@murrow.corp.sgi.com> > Amen, Jim. If this thing works like this guy spells, he's got a tough sell. > > "Announsing", "blatent" and "know one else" indeed. I don't know what his > device is, because searching for the number didn't work for me. Sounds like a > Peltier device, but I guess it could be cold fusion. > > 73, Wes -- N7WS > Always nice to see a couple of smarta*sses on the net..Hi fellows Gerhardt- From lwbyppp@epix.net Sat Mar 16 15:21:01 1996 From: johnn0isl@aol.com (John N0ISL) Newsgroups: rec.radio.amateur.antenna Subject: Re: Antenna Analyzers: AEA vs. MFJ Date: 12 Mar 1996 00:07:24 -0500 Message-ID: <4i30qc$5gr@newsbf02.news.aol.com> References: <314485D7.4F4C@ldp.com> Reply-To: johnn0isl@aol.com (John N0ISL) I've had a chance to use both. The graphics mode of the AEA was really handy. I noticed that the Outbacker factory uses the AEA antenna analyzer in their manufacturing processing, It was shown in one of the Outbacker videos sent to stores. Always use new batteries when climbing towers as both of them are pretty battery intensive. Be sure to check your new 249 or 259 analyzer closly when it arrives, I have seen an abnormally number that had problems right out of the box. If you don't quite have the budget for these, I have been using the Palomar Engineering Noise for years with great success.... John Douglas, N0ISL AX.25 N0ISL@KZ7I.#MSP.MN.USA.NOAM I'm in Minnesota only because I must be somewhere! From lwbyppp@epix.net Sat Mar 16 15:21:02 1996 From: Rolfe Tessem Newsgroups: rec.radio.amateur.antenna Subject: Antenna Analyzers: AEA vs. MFJ Date: Mon, 11 Mar 1996 14:58:15 -0500 Message-ID: <314485D7.4F4C@ldp.com> Does anyone have any thoughts on the relative merits of these two devices? The AEA appears to be better designed from an ergonomic standpoint, while the MFJ seems to have more features and beats AEA on price by a substantial margin. -- Rolfe Tessem | Lucky Duck Productions, Inc. rolfe@ldp.com | 96 Morton Street (212) 463-0029 | New York, NY 10014 From lwbyppp@epix.net Sat Mar 16 15:21:03 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: Antenna Analyzers: AEA vs. MFJ Date: Tue, 12 Mar 96 18:39:42 GMT Message-ID: <4i4gl6$eka@crash.microserve.net> References: <314485D7.4F4C@ldp.com> <4i35me$8lj@newsbf02.news.aol.com> parf@aol.com (Parf) wrote: >When I spoke to AEA about the accuracy I was told "that's >about what you should expect for a $400 instrument"- I sold it. The Autek analyzer doesn't cover VHF, but the price is certainly right ($130). Anyone know how it's construction, accuracy and features stack up against the other two? 73, Jack WB3U From lwbyppp@epix.net Sat Mar 16 15:21:04 1996 From: parf@aol.com (Parf) Newsgroups: rec.radio.amateur.antenna Subject: Re: Antenna Analyzers: AEA vs. MFJ Date: 12 Mar 1996 01:30:38 -0500 Message-ID: <4i35me$8lj@newsbf02.news.aol.com> References: <314485D7.4F4C@ldp.com> Reply-To: parf@aol.com (Parf) I have owned them both -The AEA VHF/UHF and the MFJ HF-VHF w/ resistance meter. I also own a brand new HP 8711B network analyzer that I used as a benchmark. The AEA was quite optimistic in its readings and became more so as the freq got higher. At 70cM it indicated 1:1 when the load was a precision 75 Ohm termination. The MFJ was more accurate at VHF (it does not do UHF). When I spoke to AEA about the accuracy I was told "that's about what you should expect for a $400 instrument"- I sold it. Dale WA2YPY From lwbyppp@epix.net Sat Mar 16 15:21:05 1996 From: jjo@tekla.fi (Jari Jokiniemi) Newsgroups: rec.radio.amateur.antenna Subject: Re: Antenna Analyzers: AEA vs. MFJ Date: 13 Mar 1996 06:32:50 GMT Message-ID: References: <314485D7.4F4C@ldp.com> <4i35me$8lj@newsbf02.news.aol.com> I have the Autek RF-1. A friend of mine who knows more about RF technology than I did pretty extensive testing of the device. Seems to be pretty accurate. There is one problem, though. The device may to produce a lot of harmonics when used in low temperatures (-10 degrees Celsius). This may be the reason for the fact that when used outside in winter the SWR readings are far too high. At least in our test case. Another friend has a MFJ. Autek sure has more features and is capable of more different measurements. In most common cases the MFJ is easier to use because it has analog readout instead of a digital one. -- Jari Jokiniemi, jari.jokiniemi@tekla.fi, OH2MPO, OH3BU Tekla Oy, Koronakatu 1, 02210 Espoo, 90-8879 474 From lwbyppp@epix.net Sat Mar 16 15:21:06 1996 From: kb6ojs@earthlink.net (Steve Silverwood) Newsgroups: rec.radio.amateur.antenna Subject: Re: Antenna for apartment Date: Tue, 12 Mar 1996 16:44:16 GMT Message-ID: <4i49nl$3fa@ecuador.it.earthlink.net> References: <4hicb8$msv@bolivia.it.earthlink.net> <4hmtb0$o67@crash.microserve.net> Reply-To: kb6ojs@earthlink.net jackl@pinetree.microserve.com (WB3U) wrote: >Seems to me your two biggest problems will be A) finding an >antenna that is both efficient and unobtrusive, and B) TVI/RFI. >The first could be solved reasonably well with a shortened dipole >made from magnet wire and fed with TV twinlead. If this was driven >by a 275 watt Johnson Matchbox (and if the run of line was reasonably >short), you could have a pretty efficient system. From the comments I've received elsewhere, this sounds like the best solution. Just out of curiosity, is there a real advantage between using twin-lead for the feed over using coax with a balun? >The severity of the second problem depends in large part on whether >your neighbors already know that you're a ham. Other than that, >TVI will be minimized by using a low pass filter at the output of the >rig. TVI and RFI will both be minimized by using a balanced antenna >that doesn't rely on earth ground to prevent unwanted radiation from >other parts of the system. Nobody at the apartment building knows about it, at least so far, so I'm not concerned about that. I'm also planning to run QRP so that should help minimize things as well. (And of course, no operating during the World Series and so forth, because (1) that tends to REALLY tick people off, (2) I'll be watching it myself, and (3) so will everyone else I would be talking to on the air! ;-) -- //Steve// Computer Associates CompuServe: 76703,3035 Fax: 714/557-1675 Internet: kb6ojs@earthlink.net Phone: 714/513-7236 America Online: KB6OJS Homepage: http://ourworld.compuserve.com/homepages/KB6OJS Personal homepage: http://www.earthlink.net/~kb6ojs From lwbyppp@epix.net Sat Mar 16 15:21:07 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: Antenna for apartment Date: Tue, 12 Mar 96 18:49:54 GMT Message-ID: <4i4h8a$eka@crash.microserve.net> References: <4hicb8$msv@bolivia.it.earthlink.net> <4hmtb0$o67@crash.microserve.net> <4i49nl$3fa@ecuador.it.earthlink.net> kb6ojs@earthlink.net (Steve Silverwood) wrote: >Just out of curiosity, is there a real advantage between using >twin-lead for the feed over using coax with a balun? A balun is likely to cause problems in this situation whether it's at the tuner (twinlead feeder) or at the antenna (coax feeder). In your situation, assuming the feedline is short, losses in the line will probably be secondary to problems that will potentially be generated by a balun. As Tom, W8JI, has pointed out, a choke balun is the most immune to the ill-effects of feeding a high impedance load. However, even if it doesn't consume power, it will can still lose balance. Given your situation and the need to keep RFI to an absolute minimum, a balanced tuner is the optimum solution. 73, Jack WB3U From lwbyppp@epix.net Sat Mar 16 15:21:08 1996 From: djones@ucs.ubc.ca (David Jones) Newsgroups: rec.radio.amateur.antenna Subject: Antenna or Mast Amp - which is better ? Date: 11 Mar 1996 21:14:16 GMT Message-ID: <4i2538$7di@nntp.ucs.ubc.ca> This is a VHF/UHF TV question, I know, but please bear with me - I couldn't find any newsgroups on Antennas other than this one... I live in Delta, B.C., about 120 miles north of Seattle, WA and wish to recieve more US TV channels... I have a roof mounted antenna which is capable of recieving one Tacoma station, albeit very noisy. I want to recieve Seattle stations, too, and wanted to know if it was better to buy a mast mounted "booster" amplifier (with say 20 to 30 dB gain) or replace my antenna with a "deep fringe" type. My antenna is about six feet long, with about 20 elements, I recall. Also, how can I find out what channels are available on UHF in my area ? Any input appreciated, -- Thanks, ...Dave ____________________________________________________________________________ David R. Jones, PEng The University of British Columbia From lwbyppp@epix.net Sat Mar 16 15:21:09 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: Antenna or Mast Amp - which is better ? Date: Tue, 12 Mar 96 23:22:15 GMT Message-ID: <4i5173$gir@crash.microserve.net> References: <4i2538$7di@nntp.ucs.ubc.ca> <826647990snz@microvst.demon.co.uk> mack@ncifcrf.gov "Joe Mack" wrote: >the lossy coax adds noise to the signal and it's about the same as >the loss. Does this mean that I could roll up 500' of lossy coax, terminate the unused end with a 50 ohm resistor, and use it as a wideband noise generator? 73, Jack WB3U From lwbyppp@epix.net Sat Mar 16 15:21:10 1996 Newsgroups: rec.radio.amateur.antenna From: mack@ncifcrf.gov (Joe Mack) Subject: Re: Antenna or Mast Amp - which is better ? Message-ID: References: <4i2538$7di@nntp.ucs.ubc.ca> Date: Tue, 12 Mar 1996 14:38:34 GMT In article <4i2538$7di@nntp.ucs.ubc.ca> djones@ucs.ubc.ca (David Jones) writes : >This is a VHF/UHF TV question, I know, but please bear with me - I couldn't >find any newsgroups on Antennas other than this one... > >I live in Delta, B.C., about 120 miles north of Seattle, WA and wish to >recieve more US TV channels... I have a roof mounted antenna which is >capable of recieving one Tacoma station, albeit very noisy. I want to >recieve Seattle stations, too, and wanted to know if it was better to buy a >mast mounted "booster" amplifier (with say 20 to 30 dB gain) or replace my >antenna with a "deep fringe" type. My antenna is about six feet long, with >about 20 elements, I recall. > >Also, how can I find out what channels are available on UHF in my area ? > >Any input appreciated, >-- >Thanks, ...Dave > >____________________________________________________________________________ >David R. Jones, PEng The University of British Columbia Well this is a good place to ask, most people here are looking for ways to receive as much signal as they can for the minimum price. There are 3 routes to getting a better signal at VHF low noise preamp on the mast bigger antenna higher antenna The coax is important too - it gets you twice - if you have 3db of loss in the coax your signal goes down 3db, but as well, the lossy coax adds noise to the signal and it's about the same as the loss. So your S/N goes down 6db. I would expect in your situation, you're running crappy TV grade coax with F-connectors and getting a lot of loss there. In the ham world, all weak signal people have mast mounted preamps and quite often converters on the tower to change the freq to something that will survive the trip through the coax. For $100 (or $200 if you add the converter) you get 6db more S/N with a preamp. You usually can't get 6db of S/N improvement with $100 of antenna or increase in height. Happy viewing Joe NA3T mack@ncifcrf.gov From lwbyppp@epix.net Sat Mar 16 15:21:11 1996 From: "Anthony R. Gold" Newsgroups: rec.radio.amateur.antenna Subject: Re: Antenna or Mast Amp - which is better ? Date: Tue, 12 Mar 96 16:26:30 GMT Message-ID: <826647990snz@microvst.demon.co.uk> References: <4i2538$7di@nntp.ucs.ubc.ca> Reply-To: tgold@microvst.demon.co.uk In article mack@ncifcrf.gov "Joe Mack" writes: > The coax is important too - it gets you twice - > if you have 3db of loss in the coax your signal goes > down 3db, but as well, the lossy coax adds noise > to the signal and it's about the same as the loss. > So your S/N goes down 6db. That's incredible! Regards, -- Tony - G3SKR / AA2PM email: tgold@panix.com tgold@microvst.demon.co.uk packet: g3skr@n0ary.#nocal.ca.usa.na From lwbyppp@epix.net Sat Mar 16 15:21:13 1996 From: davidc@scoot.NETis.COM (David, Michaela & Benjamin) Newsgroups: rec.radio.amateur.antenna Subject: Antenna or Mast Amp - which is better ? Date: 13 Mar 96 03:28:51 GMT Message-ID: <01BB1063.D8524E60@dns.netis.com.198.186.186.2> Date: 11 Mar 1996 21:14:16 GMT From: djones@ucs.ubc.ca (David Jones) Subject: Antenna or Mast Amp - which is better ? This is a VHF/UHF TV question, I know, but please bear with me - I = couldn't find any newsgroups on Antennas other than this one... I live in Delta, B.C., about 120 miles north of Seattle, WA and wish to recieve more US TV channels... I have a roof mounted antenna which is capable of recieving one Tacoma station, albeit very noisy. I want to recieve Seattle stations, too, and wanted to know if it was better to = buy a mast mounted "booster" amplifier (with say 20 to 30 dB gain) or replace = my antenna with a "deep fringe" type. My antenna is about six feet long, = with about 20 elements, I recall. >>>Dave: Either amp will just increase the level of noise. You need to = increase the ability of your antenna to focus closely on the target = signal to the exclusion of other sources of RF. The "deep fringe" = option sounds right. You may then capture a weak, but cleaner, signal = that is worth amplifying. Can't address the question about UHF stations in the area. Enjoy! 73, David AA1FA =20 Any input appreciated, Thanks, ...Dave _________________________________________________________________ David R. Jones, PEng The University of British Columbia From lwbyppp@epix.net Sat Mar 16 15:21:13 1996 From: mitch@primenet.com (mlmitchell) Newsgroups: rec.radio.amateur.antenna Subject: Re: Best 2M/70cm Mobile Antenna for Handheld Date: 10 Mar 1996 18:14:02 -0700 Message-ID: <31436f63.33846219@news.primenet.com> References: Reply-To: mitch@primenet.com lui@netcom.com (Stephen Lui) wrote: >What is the best 2M/70cm mobile antenna for a handheld, preferably a >magnetic mount? I visited stores and looked through catalogs and I was >inundated with countless choices! I already have a cellular phone antenna, >so I can't really install another through the glass antenna (which aren't >supposed to work that well anyways). > >Stephen Stephen, I have had the best luck with the ANLI, AT-2 and AT-2+ antennas They take an NMO mount, either permanent or other NMO mounts available. I feel that I have found the best antenna available for me and the uses that I demand from an antenna. 73 Bill (N0EVG) From lwbyppp@epix.net Sat Mar 16 15:21:15 1996 Newsgroups: rec.radio.amateur.antenna From: dstock@hpqmdla.sqf.hp.com (David Stockton) Subject: Re: Beveridge antennas Message-ID: Date: Fri, 15 Mar 1996 10:29:19 GMT References: <4i9uvp$j2v@clarknet.clark.net> Exiled on Main Street (fervor@clark.net) wrote: : Hello all... : I need to find out more about the construction of a beveridge antenna. : Anyone know where i can get some instructions on constructing a balun for : one? Please respond via email. Thanx! -Tim The Beveridge is an unbalanced antenna. You most certainly do not need a balun. It is a non-resonant antenna. length is not critical, the more the better. Try to get a few wavelengths, preferably several, at the lowest freq you want good performance (it's still useful at lower freqs) of wire supported in a straight line, at a fixed height above ground. Hit the ref books and calculate the characteristic Z of this dia wire at this height over groundplane. At the far end terminate with a resistor of same value as antenna line Z to ground. A reasonable ground system helps, but you don't need the sort of grounding array that a vertical antenna needs. Knowing the line Z, you can either use a classic antenna tuner design close to the feed end, or else use a broadband *unbalanced* matching transformer. The transformer approach makes the thing into a wideband no-tune antenna, though the antenna tuner does have an advantage if you want to push the LF limits a bit and use it where it's beginning to become more of a terminated longwire..... One very nice touch is a remote control to open the terminating resistor. This allows you to use it better as a longwire below it's "Beveridge" type frequencies, and can also give a choice of directional patterns above it. If you have a farm and a long hedgerow or fence, run one above it. Great height seems less necessary with these things than a lot of other types, 15 foot or so has been known to work fine. They have a rising gain with freq characteristic, as they become more and more sharply directional. Rotating one could be a bit of a problem....... Governments used to use fans of Beveridges (rarely) and fans of Rhombics (more often) to cover full HF and all directions. Cheers David GM4ZNX From lwbyppp@epix.net Sat Mar 16 15:21:16 1996 From: hamop@aztec.asu.edu (CHARLES J. MICHAELS) Newsgroups: rec.radio.amateur.antenna Subject: Re: Connector losses Date: 10 Mar 1996 05:09:26 GMT Message-ID: <4hto66$n8c@news.asu.edu> Jack, Your posting incorrectly ascribed the fololowing to me - >IMO, the most reliable answer anyone can give is "I don't know". >That's the one answer in life we can absolutely depend on being >correct. Unless they're lying. 73, Jack WB3U My quote of Thompson (Lord Kelvin) must be properly interpreted. I>E. If you can't put numbers on it you probably don't know what you are talking about. The emphesis must be on the YOP//// YOU , that is , it is a test you give yourself. Charlie, W7XC -- From lwbyppp@epix.net Sat Mar 16 15:21:17 1996 From: w8jitom@aol.com (W8JI Tom) Newsgroups: rec.radio.amateur.antenna Subject: Re: CTSVR vs. Voyager DX? Date: 14 Mar 1996 00:08:14 -0500 Message-ID: <4i89ju$5us@newsbf02.news.aol.com> References: In article , RMCCARTY@DELTANET.COM (Roger A. McCarty) writes: > >Anybody ever have the opportunity to do a heads up comparison between the >Uni-Hat CTSVR Vs. the GAP Voyager DX? ANy data is appreciated. > >Roger KD6CC > > They did a comparison of the two at a ham's house in Los Alamos NM. The Uni-Hat won. Tom From lwbyppp@epix.net Sat Mar 16 15:21:18 1996 From: purge@wintermute.co.uk (Jason) Newsgroups: rec.radio.amateur.antenna Subject: Cushcraft AP8A & APR18A SWR problem Date: Tue, 12 Mar 1996 19:43:37 GMT Message-ID: <4i4m77$3fn@Titania.wintermute.co.uk> Hi there, I have a cushcraft AP8A HF vertical antenna mounted on the gable end of my house and need to attach ground radials to it to get the SWR down to below 1:1.5 on all 8 bands. I have the cushcraft APR18A radial kit and was wondering if anyone has had experience with the positioning of the many radials in the same mounting position as mine. Obviously mounting the radials in one of the directions is impossible because there is no roof to support them. Have you had the same problem and if so how did you overcome it? Are there any designs of matching units which can be used at the base as in the R7 and R5 verticals which would do without the need for radials? Your comments would be most welocme. Many thanks in advance 73 Jason GM0VKQ QTH Aberdeen Scotland UK From lwbyppp@epix.net Sat Mar 16 15:21:18 1996 From: anibal@banana.speed.satlink.net (Anibal Aguirre) Newsgroups: rec.radio.amateur.antenna Subject: Re: Discone Radiation Patterns? Date: Wed, 6 Mar 96 20:44:59 EST Message-ID: <3b2cucn60.alamito@banana.speed.satlink.net> Reply-To: anibal@banana.speed.satlink.net References: <4hojru$qq2@newsbf02.news.aol.com> <4hphrs$4vua@info4.rus.uni-stuttgart.de> In <4hphrs$4vua@info4.rus.uni-stuttgart.de> moritz@ipers1.e-technik.uni-stuttgart.de () wrote: >>Can anyone out there tell me what type of radiation pattern a VHF/UHF >>discone exhibits? Is it roughly equal to a 1/4 wave or what? > >Hi Zack, > >The gain is roughly comparable to a 1/4 wave, but the pattern changs >in a peculiar way as you move from the lowest to the highest specified >frequency. I have seen an extensive set of diagrams in an professoional >antenna engineering handbook. > >73, Moritz DL5UH > > > > Zack:practically de discone gain is lowest than 1/4 wave. remember that gain*BW=CONST. -- --- E-mail: anibal@banana.speed.satlink.net Buenos Aires - Argentina From lwbyppp@epix.net Sat Mar 16 15:21:19 1996 From: moritz@ipers1.e-technik.uni-stuttgart.de () Newsgroups: rec.radio.amateur.antenna Subject: Re: Discone Radiation Patterns? Date: 8 Mar 1996 14:57:00 GMT Message-ID: <4hphrs$4vua@info4.rus.uni-stuttgart.de> References: <4hojru$qq2@newsbf02.news.aol.com> >Can anyone out there tell me what type of radiation pattern a VHF/UHF >discone exhibits? Is it roughly equal to a 1/4 wave or what? Hi Zack, The gain is roughly comparable to a 1/4 wave, but the pattern changs in a peculiar way as you move from the lowest to the highest specified frequency. I have seen an extensive set of diagrams in an professoional antenna engineering handbook. 73, Moritz DL5UH From lwbyppp@epix.net Sat Mar 16 15:21:20 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: FCC-Out of Control??? Please Read Date: Tue, 12 Mar 96 16:21:15 GMT Message-ID: <4i48hk$dvv@crash.microserve.net> References: <4i34k7$m9@news.internetmci.com> drbs.rick.eutsler@internetmci.com (Rick Eutsler) wrote: >Prepared to use force if necessary, federal police arrived at 8 AM on >March 7, 1996, to remove a small radio transmitter from the home of >A.L. Kobres, a long-time radio enthusiast. There is no question that the F.C.C.'s methods of allotment are wrong. Government does not own the magnetic spectrum any more than it owns all land, all personal property, or the heat from the sun. It is also evident that ideas transmitted over the air, regardless of format, fall under the Constitutionally-protected right to free speech. Nevertheless, and regardless of the sins of the F.C.C., the act of transmission on a frequency one does not own is trespass. Kobres was indeed exercising his right to free speech, but the F.C.C. did not infringe on that. They merely removed a trespasser from property that didn't belong to him. Kobres' actions are similar to someone who breaks into their neighbor's house, then claims they have a right to be there because they're talking. Ridiculous. 73, Jack WB3U From lwbyppp@epix.net Sat Mar 16 15:21:22 1996 From: Cecil Moore Newsgroups: rec.radio.amateur.antenna Subject: G5RV beam Date: 11 Mar 1996 19:17:33 GMT Distribution: world Message-ID: <4i1u8d$pu8@chnews.ch.intel.com> I've been experimenting with EZNEC and my 102 ft dipole trying to better the 40m radiation pattern. EZNEC says that a 66 ft reflector 10 ft away will give 9dbi gain over real ground with a TOA of 50 degrees and a horizontal beam width of 100 degrees. From my AZ location, that covers all the US east of N.Mex, the northern half of South America, most of Africa, and most of Europe. By using a 104 ft reflector 10 ft away, there's three powerful (10dbi+) lobes on 20m, one toward Europe, one toward South Africa, and one toward Mexico/South America. By using two 10 ft pieces of fiberglas, I can support the whole thing on 2 poles. By flipping the driven element and the reflector, I can reverse the direction to favor the west. I'm familiar with half-wave wire beams. Has anybody else explored the multi-lobed feature of a 3/2 WL wire beam? 73, Cecil, KG7BK, OOTC (not speaking for my employer) From lwbyppp@epix.net Sat Mar 16 15:21:22 1996 From: rval58@aol.com (Rval58) Newsgroups: rec.radio.amateur.antenna Subject: G5RV coax length Date: 15 Mar 1996 11:41:39 -0500 Message-ID: <4ic6k3$df7@newsbf02.news.aol.com> Reply-To: rval58@aol.com (Rval58) I have a pre-assembled G5RV that uses 300 Ohm twinlead and RG-8X coax. I hear that a varying COAX length can effect the match?? Currently, the SWR is about 4 or 5:1 on average across the bands. Not very pleased, obviously. I wonder if anyone has had success trimming or adding to the RG-8X to tweak SWR? The coax is just as it was currently. My lowest SWR is on 10M around 28.500 at 1.5:1. The antenna is up 45 feet. From lwbyppp@epix.net Sat Mar 16 15:21:23 1996 Newsgroups: rec.radio.amateur.antenna From: n4lq@iglou.com (Steve Ellington) Subject: Re: G5RV coax length Message-ID: References: <4ic6k3$df7@newsbf02.news.aol.com> Date: Fri, 15 Mar 1996 17:39:47 GMT Yes. The longer the coax the lower the swr appears due to loss in the feeder. If you make it at least 70ft of RG-58, your swr will appear quite low. I also found that if you wad the coax up and let it lay on the ground the swr appears even lower. All of this goes to show the how the G5RV was never intended to be a multiband antenna in the first place when fed with coax. Only 20 meters was originally considered. MR G5RV himself recommends using open wire feeders when used as a multiband antenna. Most antenna manuals have charts showing the effect of line loss on swr. A lossy coax can turn a 5:1 swr into an nice 1.2:1 if it is long enough. I suggest you either replace the coax with open line or just put up with the high swr and use a tuner. Remember, the better and shorter your coax is, the higher the swr will appear. Further, when a line has a mismatch like yours, the swr will appear to vary for different lengths of line on any given frequency. Sometimes a decent compromise can be achieved by experimenting with various short sections of coax added to your feeder. This is real easy on the higher bands where just a short 3ft jumper from the tuner to the rig can make a huge different in swr READINGS. Rval58 (rval58@aol.com) wrote: : I have a pre-assembled G5RV that uses 300 Ohm twinlead and RG-8X coax. I : hear that a varying COAX length can effect the match?? Currently, the SWR : is about 4 or 5:1 on average across the bands. Not very pleased, : obviously. I wonder if anyone has had success trimming or adding to the : RG-8X to tweak SWR? The coax is just as it was currently. My lowest SWR : is on 10M around 28.500 at 1.5:1. : The antenna is up 45 feet. -- Steve Ellington N4LQ@IGLOU.COM Louisville, Ky From lwbyppp@epix.net Sat Mar 16 15:21:25 1996 From: vfiscus@mcn.net (Vince Fiscus, KB7ADL) Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.equipment Subject: GAP Voyager DX vertical antenna. Date: Tue, 12 Mar 96 00:40:53 GMT Message-ID: <4i2h8i$r80@news.mcn.net> Is the GAP Voyager DX a good vertical ? From lwbyppp@epix.net Sat Mar 16 15:21:25 1996 Newsgroups: rec.radio.amateur.antenna From: zdanowsk@cybernex.net Subject: Re: Glass mount dualband antenna Message-ID: References: <4htn6p$oqr@newsbf02.news.aol.com> Date: Tue, 12 Mar 1996 07:14:50 GMT frankb2686@aol.com (FrankB2686) wrote: >Anyone have experience (good or bad) using a glass mount 2m/70cm antenna? >Comments on installation, manufactures, etc. would be appriciated. >73 Frank WD6AGS Does anyone have any experience using the glass mount, is the and difference to rx or tx as opposed to drilling a hole into my brand new car. Im using the Vertex 99 channel uhf model. Any make or model? From lwbyppp@epix.net Sat Mar 16 15:21:26 1996 From: burch@netline.net (Burch Akin) Newsgroups: rec.radio.amateur.antenna Subject: Re: Glass mount dualband antenna Date: Wed, 13 Mar 1996 14:10:39 GMT Message-ID: <4i6krq$fo2@tesla.netline.net> References: <4htn6p$oqr@newsbf02.news.aol.com> zdanowsk@cybernex.net wrote: >frankb2686@aol.com (FrankB2686) wrote: >>Anyone have experience (good or bad) using a glass mount 2m/70cm antenna? >>Comments on installation, manufactures, etc. would be appriciated. >>73 Frank WD6AGS >Does anyone have any experience using the glass mount, is the and >difference to rx or tx as opposed to drilling a hole into my brand new >car. Im using the Vertex 99 channel uhf model. >Any make or model? I have owned two glass mount antennas. The first one was an Antenna Specialist two meter antenna and I could never get the SWR below 3:1. I bought a Tucker 2 meter glass mount (that was about half the price of the Antenna Specialist) and it was able to get the SWR under 1.5:1. Most glass mounts are limited to 50 watts, although I have seen a couple that were rated at 100 watts. I have had pretty good luck with mine, of course it is not as good as a 5/8 wavelength wip (my glass mount is a 1/4 wave.) I own a Trans Am and didn't want to put a big antenna on the car and the glass mount was perfect. It even looks nice on the car (looks like a big cell phone antenna.) While driving I can reach most repeaters within a 30 mile range or so with 20-30 watts. Burch Akin KE4ZQV From lwbyppp@epix.net Sat Mar 16 15:21:27 1996 Newsgroups: rec.radio.amateur.antenna From: o10022@a81.corp.mot.com Subject: Re: Glass mount dualband antenna Date: Wed, 13 Mar 1996 19:08:04 GMT Message-ID: <1996Mar13.190804.23193@schbbs.mot.com> References: In article zdanowsk@cybernex.net writes: > frankb2686@aol.com (FrankB2686) wrote: > > >Anyone have experience (good or bad) using a glass mount 2m/70cm antenna? > >Comments on installation, manufactures, etc. would be appriciated. > > >73 Frank WD6AGS > > Does anyone have any experience using the glass mount, is the and > difference to rx or tx as opposed to drilling a hole into my brand new > car. Im using the Vertex 99 channel uhf model. > Any make or model? I've been very pleased with my Larsen KG2/70 glass mount. Tony kc7hdt From lwbyppp@epix.net Sat Mar 16 15:21:28 1996 From: charlie@netdepot.com (Charlie Fortner) Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew Subject: ground a 5/8 wave on a trunk lip mount? Date: Wed, 13 Mar 1996 21:12:15 -0500 Message-ID: I've got a trunk lip mount and I want to use a 5/8 wave antenna with it. If I attach a piece of wire running from the ground of the antenna to a suitable ground in the trunk, will this have the same affect as putting the antenna on the roof of my car? Thanks. Charlie Fortner KF4GJQ From lwbyppp@epix.net Sat Mar 16 15:21:29 1996 From: u00y0115@hsc.hac.COM Newsgroups: rec.radio.amateur.antenna Subject: Re: Ham-Ant Digest V96 #126 Date: 13 Mar 96 18:04:12 GMT Message-ID: <9603131804.AA10081@hscs008.hsc.hac.com> >I'm looking for a source for a 10M flexible rubber antenna for a SSB 10M >handheld. I tried getting one from Radio Shack that they sell for their >CB HT to cut it down a bit, but they never delivered on the special >order. I know this kind of antenna won't be efficient, but I am looking >for one just the same. >73 Dave WB0GAZ dgf@netcom.com Why don't you try Azden for a rubber duck, they sell a hand-held 10m rig and you could get the rubber duckie they use for that one. From lwbyppp@epix.net Sat Mar 16 15:21:30 1996 From: kr4tg@mindspring.com (mike del pozzo) Newsgroups: rec.radio.amateur.antenna Subject: help, mutual coupling... Date: Tue, 12 Mar 1996 12:10:50 GMT Message-ID: <4i3phc$mf1@B1FF.mindspring.com> Hello Guys, seems I have a new problem with my 4 element Quad coupling with my 160 mtr inverted V. only have this problem with 20 mtrs. would like to solve this short of moving the 160 antenna. Quad boom is at 80 ft. and 160 antenna is at 65 ft. and fed W/ open line for use on 80/40, though this will change to a 4 Square soon. Would like to solve problem w 160 antenna. Would going to 50 Ohm coax fix? Tnx in advance KR4TG, Mike From lwbyppp@epix.net Sat Mar 16 15:21:31 1996 From: pmarkham@sun.lssu.edu (Peter Markham) Newsgroups: rec.radio.amateur.antenna Subject: Re: HF dipole for VHF/UHF Date: Tue, 12 Mar 96 15:12:59 GMT Message-ID: <4i44b4$5d9@onramp.freeway.net> References: <4hsii6$1ct@news.asu.edu> I have wondered about the possibility and practicality of using a 75m dipole, center fed with 450 ladder (window?) line, on vhf/uhf. I have never seen the subject touched upon in my limited printed resources, or mentioned in this group articles for the month I have been reading them. Given high power computer analysis of antennas, matching networks, and operating environments coupled with the intellect evident among the postings, I suspect that someone has played with the idea. Anyone willing to share their insight or knowledge of the subject? Associated with this subject is that of building balanced vhf/uhf matching networks (tuners) and baluns for use with the above idea antenna, if practical. Pete, wa4hei From lwbyppp@epix.net Sat Mar 16 15:21:32 1996 From: cmoore@vegas.ch.intel.com (Cecil A. Moore~) Newsgroups: rec.radio.amateur.antenna Subject: HF Fractal Antennas? Date: 12 Mar 1996 15:13:06 GMT Distribution: world Message-ID: <4i44a2$112o@chnews.ch.intel.com> Communications Quarterly, Summer '95, carried an article on Fractal Antennas by Chip Cohen, N1IR. Looks like a great way to shrink an HF half-wave dipole for an attic installation. Has anybody tried an HF fractal antenna? 73, Cecil, KG7BK, OOTC (not speaking for my employer) From lwbyppp@epix.net Sat Mar 16 15:21:32 1996 From: Ellie Emmanuel Newsgroups: rec.radio.amateur.antenna Subject: HF Rhombic Antennas Date: 11 Mar 1996 21:57:53 GMT Message-ID: <4i27l1$1f5@express.ior.com> Can anyone help with some basic info on HF Rhombics. I have recently purchase sufficient land for a 2 wave on a side for 40M Rhombic or other higher band Rhombic. I am unable to find in depth info in ARRL Handbook, RSGB Handbook or others. Questions abound concerning angles at corners, heigth above ground, terminated vs unterminated etc etc etc. If someone has experience aned would be willing to share, please contact me at the following: Jim Smith - VJSH80A@prodigy.com I do not have newsgroup access at home and am using a friends computer to send this message. From lwbyppp@epix.net Sat Mar 16 15:21:34 1996 From: mluther@tamu.edu Newsgroups: rec.radio.amateur.antenna Subject: Re: HF Rhombic Antennas Date: 12 Mar 1996 07:37:47 GMT Message-ID: <4i39kb$ao0@news.tamu.edu> References: <4i27l1$1f5@express.ior.com> Reply-To: mluther@tamu.edu In <4i27l1$1f5@express.ior.com>, Ellie Emmanuel write s: >Can anyone help with some basic info on HF Rhombics. I have recently >purchase sufficient land for a 2 wave on a side for 40M Rhombic or other >higher band Rhombic. I am unable to find in depth info in ARRL Handbook, >RSGB Handbook or others. Questions abound concerning angles at corners, >heigth above ground, terminated vs unterminated etc etc etc. > >If someone has experience aned would be willing to share, please contact >me at the following: > > Jim Smith - VJSH80A@prodigy.com > >I do not have newsgroup access at home and am using a friends computer to >send this message. > Jasik's Antenna handbook has a VERY in-depth treatment of rhombics. The older W6SAI Radio Handbooks also have some information on them. Brian Beezley's MN and MNC antenna software packages come with a compromise rhombic starting point for design work with his antenna modeling package that produces the nicest complex radiation pattern display you ever saw in color. It also displays the rather interesting large number of narrow spike lobes in various directions both in the horizontal and vertical plane for you to see just how these antennae really radiate. A friend of mine that own a creosote plant for phone poles has played with them in east Texas for a long time. Here in tornado alley, he says they aren't all that good at all in summer QRN, because of the high angle spikes that pick up all the interference from every close range TRW that shows up in staticville. It rather reinforces the point that the rhombic is a wonderful antenna for fixed point to point circuits where the path length is also known so that one can optimize the plant for both the required single direction and desired takeoff angle. On these circuits, these antennae are wonderful. If you look carefully at this antenna, unless your amateur radio desires for a signal are eally confined to only a few directions, it can get mighty expensive putting up a number of them to fill in the holes around the compass. I have the space for a couple good ones. I gave up thinking about them when I started calculating the cost per DB per direction and what all it REALLY would take to put up a plant full. Besides, they are still the same old story about having to be at least 3/4 wave length above the ground at the desired frequency for the right takeoff angles. That, on 40 meters means up above 90 feet or so. And on 80, it means up around 160 feet or so. Just beecause you have the horizontal space, does not mean you have the money for LOTS of 180 foot towers. At least in MY case..... :) Mike W5WQN as a guest at leviathan.tamu.edu From lwbyppp@epix.net Sat Mar 16 15:21:35 1996 From: Ellie Emmanuel Newsgroups: rec.radio.amateur.antenna Subject: Re: HF Rhombic Antennas Date: 15 Mar 1996 16:04:55 GMT Message-ID: <4ic4f7$dsa@express.ior.com> References: <4i27l1$1f5@express.ior.com> <4i39kb$ao0@news.tamu.edu> To: MLUTHER@TAMU.EDU Thanks for the comeback. It does indeed seem you are confirming my suspicions. I agree that the cost to put such a critter in the air can be a whole lot. Another direct reply also suggested that for the same cost I could put up a whole farm full of wire antennas with just a few poles and pulleys. 73, Jim, KA7APJ VJSH80A@prodigy.com From lwbyppp@epix.net Sat Mar 16 15:21:36 1996 From: tracker@indirect.com (Mark Saunders) Newsgroups: rec.radio.amateur.antenna Subject: Re: Hygain 18AVT need help Date: Wed, 13 Mar 1996 22:52:09 UNDEFINED Message-ID: References: <3133CB76.5E7@deepcove.com> In article <3133CB76.5E7@deepcove.com> Earl Richardet writes: >I'm having trouble matching my recently acquired Hygain 18AVT antenna. I can 't get below 3-1 >SWR. Does anyone have the original starting measurements for this antenna an d or installation >instructions. >Desparate VE7MLJ EARL Hi Earl, I've got the information you need. Send me your snail mail address and I'll send it off to you. Mark Saunders - KJ7BS Glendale, AZ PACKET: KJ7BS@KC7Y.AZ.USA.NOAM INTERNET: tracker@indirect.com From lwbyppp@epix.net Sat Mar 16 15:21:37 1996 Newsgroups: rec.radio.amateur.antenna From: mack@ncifcrf.gov (Joe Mack) Subject: Re: is kraus alive? Message-ID: References: <031bkck60.alamito@banana.speed.satlink.net> <4hpsas$lbk@yuma.ACNS.ColoState.EDU> Date: Thu, 14 Mar 1996 15:12:06 GMT In article <4hpsas$lbk@yuma.ACNS.ColoState.EDU> drranu@holly.ACNS.ColoState.ED U (Emarit Ranu) writes: >Anibal Aguirre (anibal@banana.speed.satlink.net) wrote: >: i`d like to know if the autor of "the antenna bible" is alive today. >: please sorry...sorry for my ignorance. >: if he`s alive, i`d like write him. >: sorry again. >: 73, anibal. >: LU4DVJ > > My Electromagnetics book copyrighted 1992 by him says he is > "teaching while serving as a consultant to government and industry". > > >-- > -Emarit, KG0CQ 73's drranu@holly.ColoState.EDU > Electrical Engineering, Colorado State Univeristy > Packet: KG0CQ@KF0UW.#NECO.USA.NOAM > All generalizations are bad. Censorship: ###### > _._ __. _____ _._. __._ He has just been given some ham award for service to the (ham) community, which will be presented at the Dayton HamVention. I called up his (old) dept at the university a few years back, trying to find out about him. The secretary just told me to phone him at home. I said something about there must be people bothering him all day if people like me just phoned him up. She didn't seem to think it would be a problem. SO I called him up and said hello. I was trying to track down his book "The Big Ear", as it seemed to be out of print. He didn't know where I could get it. However I talked to the man himself. Quite something. (I later got the book through interlibrary loan via the county library - even later I foudn that CQ magazine (I think) bookstore has it) Joe NA3T mack@ncifcrf.gov From lwbyppp@epix.net Sat Mar 16 15:21:38 1996 From: tom_boza@ccm.ch.intel.com (WB7ASR) Newsgroups: rec.radio.amateur.antenna Subject: Re: ladder line and 6M antenna RESULTS? Date: 14 Mar 1996 16:20:39 GMT Distribution: world Message-ID: <4i9h0n$scm@chnews.ch.intel.com> References: <4i3r4u$g52@newsbf02.news.aol.com> denoid95x@aol.com (DeNoid95X) wrote: >I have a quick question, I was wondering if anyone was using ladder line >from their transceiver to an antenna and if so what type of antenna and >the results you have experienced. I am using a 6M two element quad and >was curious of the results of such a system with ladder line 300/450 Ohm. > >N9RLR/2 Im using my 40 meter roof mounted full size vertical which is base feed using 300 ohm ladder line and a 4:1 balum on 6 meters. The 4:1 balum connects via 50 ohm coax to a homebrew 6 meter antenna tuner, which gives me a 1:1 swr match to my 100 watt output xcvr. It has been working with quite good results, yealding me many DX station QSOs during pipeups against local guys who are running 3 ele beams. Per an antenna modeling software program, I have a 6.4db gain omni pattern with a take off angle of 64 deg. Tom... From lwbyppp@epix.net Sat Mar 16 15:21:39 1996 From: denoid95x@aol.com (DeNoid95X) Newsgroups: rec.radio.amateur.antenna Subject: ladder line and 6M antenna RESULTS? Date: 12 Mar 1996 07:36:46 -0500 Message-ID: <4i3r4u$g52@newsbf02.news.aol.com> Reply-To: denoid95x@aol.com (DeNoid95X) I have a quick question, I was wondering if anyone was using ladder line from their transceiver to an antenna and if so what type of antenna and the results you have experienced. I am using a 6M two element quad and was curious of the results of such a system with ladder line 300/450 Ohm. N9RLR/2 From lwbyppp@epix.net Sat Mar 16 15:21:41 1996 From: Dave Heil Newsgroups: rec.radio.amateur.antenna Subject: Re: ladder line and 6M antenna RESULTS? Date: Sat, 16 Mar 1996 16:59:09 +0000 Message-ID: <314AF35D.231@clinet.fi> References: <4i3r4u$g52@newsbf02.news.aol.com> DeNoid95X wrote: > > I have a quick question, I was wondering if anyone was using ladder line > from their transceiver to an antenna and if so what type of antenna and > the results you have experienced. I am using a 6M two element quad and > was curious of the results of such a system with ladder line 300/450 Ohm. > > N9RLR/2 In the early days of TV, when folks lived in a valley or other area shielded from good reception, it was common practice to place the antenna perhaps a couple of hundred feet away from the house, say on the side of a hill. Open wire line was run up the hill to the antenna and reception was good. Don't forget that 30 years ago, the most common TV lead-in was 300 ohm twin lead. If you use a balun at each end of the feed line to transform the impedances to 50 ohms, you'll end up with less loss than if you'd used coaxial cable. You'll need to use standoff insulators to keep the stuff away from the house and any nearby metal objects. Good luck. 73, Dave OH2/K8MN downtown Helsinki From lwbyppp@epix.net Sat Mar 16 15:21:42 1996 From: sabinw@crpl.cedar-rapids.lib.ia.us (Bill W0IYH) Newsgroups: rec.radio.amateur.antenna Subject: lowband antennas Date: 13 Mar 1996 19:07:31 GMT Distribution: world Message-ID: <4i76dj$vgc@flood.weeg.uiowa.edu> Reply-To: SABINW@crpl.cedar-rapids.lib.ia.us >I never thought it was preferable to ground the system at the base of >the vertical. A bit of misunderstanding, Jack. My assumption is that the radials are all returned to the braid of the coax. I did not suggest a ground rod at the antenna. The coax braid then returns to the xmtr, which is probably grounded to a good system ground of some kind. If the number of radials or length of radials is not adequate, *some* of the return current *at the antenna* may not be collected by the radials and may seek *another route* back to the xmtr via an *earth* path. For some time now I have suspected that may, in fact, be happening if the radial system is poor. I tried to word my post as carefully as possible so that there would be no misinterpretations. Apparently I was not careful enough (mea culpa). Also, I referred only to verticals that are at ground level (ground mounted). I would hope to restrict the scope to just the things that I mentioned. I am especially anxious not to get into another spool of thread on this topic. 73, Bill From lwbyppp@epix.net Sat Mar 16 15:21:43 1996 From: Mark Schoonover Newsgroups: rec.radio.amateur.antenna Subject: LW Antenna for Apartment Dweller Date: Wed, 13 Mar 1996 09:05:43 -0800 Message-ID: <31470067.42BE@cts.com> Thanks for reading! I'm looking for plans to build LW antennas for use in an apartment. My main goal is for DXing beacons and NAVTEXT broadcasts. Any pointers would be greatly appreciated! Thanks Again! Mark --KA6WKE From lwbyppp@epix.net Sat Mar 16 15:21:44 1996 From: n5zgt@swcp.com (Brian Mileshosky) Newsgroups: rec.radio.amateur.antenna Subject: Need Info on G5RV Antenna Date: Fri, 08 Mar 1996 02:07:58 GMT Message-ID: <4ho8ga$ici@sloth.swcp.com> Reply-To: n5zgt@swcp.com Hello Everybody, I am thinking of buying a G5RV antenna. Are these antennas pretty good? How about on 80 and 40? And I have heard they can be used on 160 meters. How does it to on that band? All information would be greatly appreciated! Thanks! Best of 73, Brian, N5ZGT... ________________________________________________________________________ Boy Scouts of America Amateur Radio J.A.S.M. - Troop 41 N5ZGT Albuquerque, NM Packet: N5ZGT @ KC5IZT.ALBQ.NM.USA.NA Great Southwest Council Internet: n5zgt@swcp.com O.A. Lodge 66 _______________________________________________________________________ From lwbyppp@epix.net Sat Mar 16 15:21:45 1996 From: rhstein@interaccess.com (Ronald H Steinberg) Newsgroups: rec.radio.amateur.antenna Subject: Need info on Heath B1 balun Date: 12 Mar 1996 11:31:13 GMT Message-ID: <4i3na1$10d@nntp.interaccess.com> Picked up an old Heath coil balun and would like a copy of the instruction/specs. Does this type of balun (air coil) offer any real advantages or disadvantages over the new torrid based units? RON K9IKZ From lwbyppp@epix.net Sat Mar 16 15:21:46 1996 From: cowanr@isma8.monmouth.army.mil Newsgroups: rec.radio.amateur.antenna Subject: OOTC Date: 11 Mar 96 14:23:44 GMT Message-ID: <4722BAED@MHS> Thanks Tom. You make it perfectly clear. I thought it was Old OSCAR Training Course or Old Olympiad Tiddiliewinks Character cul8tr 73, Roland >In article <4606E8C2@MHS>, cowanr@isma8.monmouth.army.mil writes: >Could someone tell me what an OOTC is? >Is that an EE on steriods or or what? >73, >Roland WF4P >Abbreviations cause QRK 1. Since I am not QRL at QTR 1:05pm, I thought I'd >QSP QTC-1. OOTC is the Old old timers club.. >It means the OM's been QRV since Hector was a pup, before the days of MTV >and even TTL. QSL? >BCNU, >Tom From lwbyppp@epix.net Sat Mar 16 15:21:47 1996 From: Jake Middlebrook Newsgroups: rec.radio.amateur.antenna Subject: Re: Organic verticals again Date: 13 Mar 1996 22:00:02 GMT Message-ID: <4i7gh2$juj@theopolis.orl.mmc.com> References: <313E4F7F@central.advance.com.au> <4hvmdk$suk@rover.ucs.ualberta.ca> To: rwa@cs.athabascau.ca I've heard of some lore that says a pine tree killed by lighting when the sap is high will affect antenna patterns but I never heard of anyone actually trying to drive one. I'll pay a quarter to watch him tune it by trimming the capacity hat with hedge clippers. HI. From lwbyppp@epix.net Sat Mar 16 15:21:48 1996 From: rwa@cs.athabascau.ca (Ross Alexander) Newsgroups: rec.radio.amateur.antenna Subject: Re: Organic verticals again Date: 14 Mar 1996 01:10:29 GMT Message-ID: <4i7rm5$d14@rover.ucs.ualberta.ca> References: <313E4F7F@central.advance.com.au> <4hvmdk$suk@rover.ucs.ualberta.ca> <1996Mar11.020108.7926@ke4zv.atl.ga.us> gary@ke4zv.atl.ga.us (Gary Coffman) writes: >In article <4hvmdk$suk@rover.ucs.ualberta.ca> rwa@cs.athabascau.ca (Ross Alex ander) writes: >>I just went out and measured the resistance between two plated 8" lag >>screws driven into a meter of green aspen, about 30 in cm diameter. >>It's well over 100 k ohms (sorry, didn't have a megger handy.) Maybe >>some other trees are better, but five or six orders of magnitude >>better? Highly unlikely. >At what frequency did you take this measurement? [...] Good point. Just went outside with my Autek RF analyst and did some more measurements. Got 1300 ohms at 3.5 Mhz, 550 ohms at 7.15 Mhz, 230-ish ohms at 20m. That's per foot. Although I did measure higher (90 ohms per foot indicated at 28.5 Mhz) I'm extremely suspicious of the results; the lead lengths start to get significant, and stray capacitance & body effects made the readings bounce all over. Does anyone here think that an 80m vertical built from 66 1k ohm resistors each having a pair of six inch leads would work well? :) I still think feedline radiation is the ticket. regards, Ross ve6pdq ps: so, does anyone else have numbers? Surely I'm not the only ham who owns a tree and a noise bridge. -- Ross Alexander, ve6pdq -- (403) 675 6311 -- rwa@cs.athabascau.ca From lwbyppp@epix.net Sat Mar 16 15:21:52 1996 From: Jake Middlebrook Newsgroups: rec.radio.amateur.antenna Subject: Re: Organic verticals again Date: 13 Mar 1996 22:00:17 GMT Message-ID: <4i7ghh$juj@theopolis.orl.mmc.com> References: <313E4F7F@central.advance.com.au> <4hvmdk$suk@rover.ucs.ualberta.ca> To: rwa@cs.athabascau.ca I've heard of some lore that says a pine tree killed by lighting when the sap is high will affect antenna patterns but I never heard of anyone actually trying to drive one. I'll pay a quarter to watch him tune it by trimming the capacity hat with hedge clippers. HI. From lwbyppp@epix.net Sat Mar 16 15:21:53 1996 From: aga@ssguest.west.sun.com (Tony Angerame - Sun SSE) Newsgroups: rec.radio.amateur.antenna Subject: OSCAR 2mt DwnLnk Date: 13 Mar 1996 17:12:07 GMT Distribution: world Message-ID: <4i6vl7$ddf@newsworthy.West.Sun.COM> Reply-To: aga@ssguest.west.sun.com I need some help choosing an antenna for the 2 meter downlink. I am trying to build a solid receiver setup at as low a cost as is reasonable. I allready have a Ye asu FT-101ZD receiver at 14mhz using an Ameco Nuvistor convertor. It's old but sur e seems to have plenty of gain and is a stable setup. I plan on making up for the conv ertors mediocre noise figure by installing a GasFet preamp at the antenna which will be only 20 feet or less away from the shack. I am contemplating a six turn helix but haven't worked out the mechanical details. (Need to get to Home Depot hihi). A s an alternative antenna I am thinking of the KLM,Hy-gain or M2 Circular polarized yagis. I have notice they make both a large and a smaller model (15ele vs 11 or so). Which one is my best bet? Should I go for the higher or lower gain model? I like the idea of switching RHCP and LHCP but I'm not sure how important it is? Slowly but sh urely and before the sunspots are back! TIA Tony WA6LZH From lwbyppp@epix.net Sat Mar 16 15:21:54 1996 Newsgroups: rec.radio.amateur.antenna From: webbte <> Subject: Paint on a Vertical Message-ID: Reply-To: (webbte) Date: Fri, 8 Mar 1996 18:48:14 GMT I'm about to move into a development with the usual antenna restrictions. Just wondered if anyone has had any luck applying a coat of dark colored paint to a vertical? I realize the paint would have to be a non-metalic type. It would serve to "hide" the antenna within a small stand of pine trees by blocking any reflections from the bright aluminum. Any ideas? 73 de Ted / AC4CS ted.webb@columbiasc.attgis.com From lwbyppp@epix.net Sat Mar 16 15:21:55 1996 Newsgroups: rec.radio.amateur.antenna From: bb840@scn.org (James Aeschliman) Subject: Re: Paint on a Vertical Message-ID: Reply-To: bb840@scn.org (James Aeschliman) References: Date: Mon, 11 Mar 1996 19:47:02 GMT In a previous article, (webbte) says: > >I'm about to move into a development with the usual antenna >restrictions. Just wondered if anyone has had any luck applying >a coat of dark colored paint to a vertical? I realize the paint >would have to be a non-metalic type. It would serve to "hide" >the antenna within a small stand of pine trees by blocking any >reflections from the bright aluminum. Any ideas? > It should work. It's been common practice for years to coat an aluminum antenna with clear lacquer to reduce corrosion. -- Jim Aeschliman bb840@scn.org Black Diamond, Washington KD7MK From lwbyppp@epix.net Sat Mar 16 15:21:57 1996 From: w5gyj@primenet.com (James E. Bromley) Newsgroups: rec.radio.amateur.antenna Subject: Re: Paint on a Vertical Date: 12 Mar 1996 14:42:01 -0700 Message-ID: References: <4i30c9$578@newsbf02.news.aol.com> In article ted.webb@columbiasc.attgis.com (Ted / AC4CS) writes: >I'm about to move into a development with the usual antenna >restrictions. Just wondered if anyone has had any luck applying >a coat of dark colored paint to a vertical? I realize the paint >would have to be a non-metalic type. It would serve to "hide" >the antenna within a small stand of pine trees by blocking any >reflections from the bright aluminum. Any ideas? I usually paint my 2m/440 verticals flat black. No problem at all with bare aluminum - it has the effect of shorting out any loss resistance the paint might exhibit. I don't paint the plastic insulators, since any resistance in the paint could degrade the antenna's performance at that point. However, most spray-on black paints seem to use small particles of amorphous carbon black for pigment. These particles are buried in the binder and are not in contact with each other. This seems to keep the paint resistance quite high from DC up to microwaves. So loss from this source may be a moot point. Lately, I have spray-painted a plastic-covered 2m/440 gain antenna and have not noticed any degradation in SWR or on-the-air performance with distant stations. A final note on color. Black seems to fade out of sight when against just about any background. Even against a bright blue sky, there is something about it that makes the eye look past it. Jim Bromley, W5GYJ Glendale, AZ From lwbyppp@epix.net Sat Mar 16 15:21:57 1996 From: johnn0isl@aol.com (John N0ISL) Newsgroups: rec.radio.amateur.antenna Subject: Re: Paint on a Vertical Date: 11 Mar 1996 23:59:53 -0500 Message-ID: <4i30c9$578@newsbf02.news.aol.com> References: Reply-To: johnn0isl@aol.com (John N0ISL) Comet Antennas produced a version of one of their antennas in Blue, hoping it would disapper into the sky and not be so obvious. It stood out like crazy. It is also no longer for sale. I have installed a couple of "stealth" antennas that were painted a ligh grey. They were not at all obivous and there were no side effects from painting them. John Douglas, N0ISL AX.25 N0ISL@KZ7I.#MSP.MN.USA.NOAM I'm in Minnesota only because I must be somewhere! From lwbyppp@epix.net Sat Mar 16 15:21:58 1996 From: tomb@lsid.hp.com (Tom Bruhns) Newsgroups: rec.radio.amateur.antenna Subject: Re: Paint on a Vertical Date: 13 Mar 1996 16:03:07 GMT Message-ID: <4i6rjr$hg7@hpcvsnz.cv.hp.com> References: webbte () wrote: : I'm about to move into a development with the usual antenna : restrictions. Just wondered if anyone has had any luck applying : a coat of dark colored paint to a vertical? I realize the paint : would have to be a non-metalic type. It would serve to "hide" : the antenna within a small stand of pine trees by blocking any : reflections from the bright aluminum. Any ideas? Barry Ornitz, a ham who used to post in these groups occasionally, and who's a chemical engineer at a plastics plant, once told me that acrylic paint is particularly good for antenna projects, because the paint has reasonably low RF loss and tends to be more weather (UV) resistant than other paints. I suspect most non-epoxy spray paints are acrylic, but check the labels. I miss Barry's postings; I could always rely on them for accuracy and thoughtfulness. -- Cheers, Tom tomb@lsid.hp.com From lwbyppp@epix.net Sat Mar 16 15:21:59 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: Paint on a Vertical Date: Wed, 13 Mar 96 17:45:43 GMT Message-ID: <4i71s3$mda@crash.microserve.net> References: <4i30c9$578@newsbf02.news.aol.com> w5gyj@primenet.com (James E. Bromley) wrote: >I usually paint my 2m/440 verticals flat black. No problem >at all with bare aluminum - it has the effect of shorting out >any loss resistance the paint might exhibit. Hi Jim, As you mentioned later in your post, the particular paint you're using may not be conductive at these frequencies. However, if it is, the aluminum surface of the vertical isn't likely to short out the resistance in the paint. Skin effect will force the current into the paint, and it will become all or part of the path. 73, Jack WB3U From lwbyppp@epix.net Sat Mar 16 15:22:00 1996 From: Mike James Newsgroups: rec.radio.amateur.antenna Subject: Portable HF ant. suggestions? Date: Tue, 12 Mar 1996 11:40:51 -0800 Message-ID: <3145D343.5946@best.com> Greetings, Can anyone suggest a good, portable HF antenna one could put into a backpack alogn with a QRP rig? It would be nice if the antenna could be made to work o n several bands. Thanks! Mike James KE0CH From lwbyppp@epix.net Sat Mar 16 15:22:01 1996 From: Jake Middlebrook Newsgroups: rec.radio.amateur.antenna Subject: Re: Q: How would a 80m Magnetic Loop antenna look like? Date: Mon, 11 Mar 96 19:51:57 -0500 Message-ID: References: <42386306@clobber.mos.unterland.de> <4hk7lq$d8l@hobbes.cc.uga.edu> .35 wave length loop .1 wave length diameter open one end and insert a cap to resonate use large copper type or 3 inch wide copper tape you can get a good guess at cap size by .36 uH per foot If you look under ftp.funnet.fi/pub/ham there is a program called miniloop.zip which gives you the results of a magnetic loop design feed the thing with a gamma match or a shielded loop 1/6 diameter of the large loop good luck Jake WB4HPF From lwbyppp@epix.net Sat Mar 16 15:22:02 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: QUESTION: RECV better than TXMT Date: Tue, 12 Mar 96 20:13:09 GMT Message-ID: <4i4m4f$f2d@crash.microserve.net> References: <4i1k2a$hhi@lambchop> Ron Thompson wrote: >A mobile unit 40 miles away transmitting on a simplex frequency can >be heard clearly, but the mobile unit cannot hear my radio until it >gets within 10 miles. Perhaps the directivity of your yagi is reducing some of the multiple reflections that would make your signal audible to the other station. Have you tried a vertical in that situation? 73, Jack WB3U From lwbyppp@epix.net Sat Mar 16 15:22:03 1996 Newsgroups: rec.radio.amateur.antenna From: gary@ke4zv.atl.ga.us (Gary Coffman) Subject: Re: QUESTION: RECV better than TXMT Message-ID: <1996Mar12.191239.17604@ke4zv.atl.ga.us> Reply-To: gary@ke4zv.atl.ga.us (Gary Coffman) References: <4i1k2a$hhi@lambchop> Date: Tue, 12 Mar 1996 19:12:39 GMT In article <4i1k2a$hhi@lambchop> Ron Thompson write s: >I have a unique situation that needs some help: > >I live in a valley, halfway up the hill on the north side. >All the contacts I want to make are to the north of me, >which is effectively blocked by the hill I live on. Across >the valley is a big mountain that faces north. > >I have a 50 W 2M radio with a 4 Element Yagi Beam antenna >with 10db gain. > >The beam is aimed south, directly towards the big mountain. >I am effectively bouncing my signal off of it to get over >the hill I am on. If I turned the beam around, it would >would be pointed directly into the hillside. > >The problem is, my signal reception is much better than >my signal going out. Tests I have done indicate that I >can hear signals about 4 times farther away than I can >with a 3db gain whip. The 3db whip puts out signals >that can be heard about twice as far away than the beam >though. A mobile unit 40 miles away transmitting on >a simplex frequency can be heard clearly, but the mobile >unit cannot hear my radio until it gets within 10 miles. >Strange. > >Does anyone have any idea why this would happen? Sounds like you are under illuminating your reflector. This is a common source of reduced gain with dish antennas, and would also seem to apply in this case. Try removing a director from your beam to widen its main lobe. The reason the behavior appears non-reciprocal is due to the fact that the mountain isn't a focusing reflector, but rather is a scattering reflector due to its rough surface. Thus on receive, where the mountain is fully illuminated by the expanded wave from the distant station, scatter is letting more of the signal combine at your antenna than is the case for the focused beam fed toward only part of the mountain. Gary -- Gary Coffman KE4ZV | You make it, | Due to provider problems Destructive Testing Systems | we break it. | with previous uucp address es 534 Shannon Way | Guaranteed! | Email to ke4zv@radio.org Lawrenceville, GA 30244 | | From lwbyppp@epix.net Sat Mar 16 15:22:04 1996 From: "Anthony R. Gold" Newsgroups: rec.radio.amateur.antenna Subject: Re: QUESTION: RECV better than TXMT Date: Tue, 12 Mar 96 20:29:26 GMT Message-ID: <826662566snz@microvst.demon.co.uk> References: <4i1k2a$hhi@lambchop> <1996Mar12.191239.17604@ke4zv.atl.ga.us> Reply-To: tgold@microvst.demon.co.uk In article <1996Mar12.191239.17604@ke4zv.atl.ga.us> gary@ke4zv.atl.ga.us "Gary Coffman" writes: > The reason the behavior appears non-reciprocal is > due to the fact that the mountain isn't a focusing > reflector, but rather is a scattering reflector due > to its rough surface. I do not follow this. And indeed to be frank, I just don't believe it. Are you saying that this appears to be non-reciprocal but isn't. Or are you saying that this particular antenna configuration, hills and all, IS non-reciprocal. And either way, could you explain your theory with a numerical example? Regards, -- Tony - G3SKR / AA2PM email: tgold@panix.com tgold@microvst.demon.co.uk packet: g3skr@n0ary.#nocal.ca.usa.na From lwbyppp@epix.net Sat Mar 16 15:22:05 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: QUESTION: RECV better than TXMT Date: Wed, 13 Mar 96 14:32:49 GMT Message-ID: <4i6mih$lf7@crash.microserve.net> References: <4i1k2a$hhi@lambchop> <1996Mar12.191239.17604@ke4zv.atl.ga.us> <4i6iq8$g92@nadine.teleport.com> w7el@teleport.com (Roy Lewallen) wrote: >If the antenna beam were so narrow that it hits only a part of the >mountain when transmitting, wouldn't it then receive signals >only from that same part of the mountain? If so, it wouldn't matter >how much of the rest of the mountain were illuminated by the other >transmitter. I can't speak for Gary, but in my response to this I was thinking about the distant signal also being refracted/reflected near its own location. As a result of that, multiple waves might strike the mountain from various angles. If the waves arrive reasonably in-phase, and they converge at the yagi after being reflected from the mountain, the result could be the noted effect. When the yagi is used to transmit though, that effect would not necessarily be reciprocal for the distant mobile receiver. The narrow beam of the yagi would prevent the transmit signal from spreading out and would limit its chances of reflecting back to the mobile from multiple points. The mountain may simply not be reflecting the transmit signal in the correct direction to be received by the mobile, or a straight line drawn from the yagi to the mountain, and then to the mobile, may be blocked by side of the hill that the QTH is on. This is why I suggested trying a vertical. 73, Jack WB3U From lwbyppp@epix.net Sat Mar 16 15:22:07 1996 From: Ron Thompson Newsgroups: rec.radio.amateur.antenna Subject: QUESTION: RECV better than TXMT Date: 11 Mar 1996 16:23:38 GMT Message-ID: <4i1k2a$hhi@lambchop> I have a unique situation that needs some help: I live in a valley, halfway up the hill on the north side. All the contacts I want to make are to the north of me, which is effectively blocked by the hill I live on. Across the valley is a big mountain that faces north. I have a 50 W 2M radio with a 4 Element Yagi Beam antenna with 10db gain. The beam is aimed south, directly towards the big mountain. I am effectively bouncing my signal off of it to get over the hill I am on. If I turned the beam around, it would would be pointed directly into the hillside. The problem is, my signal reception is much better than my signal going out. Tests I have done indicate that I can hear signals about 4 times farther away than I can with a 3db gain whip. The 3db whip puts out signals that can be heard about twice as far away than the beam though. A mobile unit 40 miles away transmitting on a simplex frequency can be heard clearly, but the mobile unit cannot hear my radio until it gets within 10 miles. Strange. Does anyone have any idea why this would happen? Thanks! ron.thompson@bglobal.com From lwbyppp@epix.net Sat Mar 16 15:22:08 1996 From: w7el@teleport.com (Roy Lewallen) Newsgroups: rec.radio.amateur.antenna Subject: Re: QUESTION: RECV better than TXMT Date: Wed, 13 Mar 96 13:33:51 GMT Message-ID: <4i6iq8$g92@nadine.teleport.com> References: <4i1k2a$hhi@lambchop> <1996Mar12.191239.17604@ke4zv.atl.ga.us> In article <1996Mar12.191239.17604@ke4zv.atl.ga.us>, gary@ke4zv.atl.ga.us (Gary Coffman) wrote: >. . . >The reason the behavior appears non-reciprocal is >due to the fact that the mountain isn't a focusing >reflector, but rather is a scattering reflector due >to its rough surface. Thus on receive, where the >mountain is fully illuminated by the expanded wave >from the distant station, scatter is letting more >of the signal combine at your antenna than is the >case for the focused beam fed toward only part of >the mountain. Pardon my ignorance. If the antenna beam were so narrow that it hits only a part of the mountain when transmitting, wouldn't it then receive signals only from that same part of the mountain? If so, it wouldn't matter how much of the rest of the mountain were illuminated by the other transmitter. It seems to me that antenna operation would be reciprocal. There are, of course, other explanations for non-reciprocity in VHF transmitting and receiving -- different amounts of transmit power and different receiver noise figures. These sound more likely to me. Roy Lewallen, W7EL From lwbyppp@epix.net Sat Mar 16 15:22:09 1996 From: John Fleming Newsgroups: rec.radio.amateur.antenna Subject: RadioAdventure Web Site Date: Tue, 12 Mar 1996 13:12:54 +0500 Message-ID: <31453206.5F52@mailbox.mcs.net> There is a new web site, http://www.far.net/radioadventure which contains articles and info about a variety of antenna types. John Fleming From lwbyppp@epix.net Sat Mar 16 15:22:10 1996 From: Dave Perkins Newsgroups: rec.radio.amateur.antenna Subject: Replacement Antenna for Yaesu FT-411E Date: 14 Mar 1996 01:28:44 GMT Message-ID: <4i7soc$gqh@news2.cts.com> I lost the antenna that my Yaesu came with a while ago...I have an antenna for it now but I hate it..Does anyone know how I can get a replacement one...The one that the radio came with...Also, does anyone know how much it will cost..??? Please reply via email-davep@cts.com Thanx, Dave in San Diego From lwbyppp@epix.net Sat Mar 16 15:22:11 1996 Newsgroups: rec.radio.amateur.antenna From: bb840@scn.org (James Aeschliman) Subject: Re: RFI with stereo: need filter advice/RFI from AM xmtr, what to do? Message-ID: Reply-To: bb840@scn.org (James Aeschliman) References: Date: Sat, 16 Mar 1996 03:35:37 GMT In a previous article, psoper@encore.com (Pete Soper) says: > >I'm considering building low pass filters for each of the >five speaker outputs but before I build and test the first >one I thought I'd check with the collective wisdom of those >readers who have "been there, done that". My first cut would be >a series inductor of perhaps 20 microhenries and a small >cap of perhaps .01ufd to ground (numbers from memory). . . . I believe I read in a recent QST not to put by-pass capacitors on speakers connected to a solid state amplifier, because they may cause a runaway situation and burn up the amplifier. I could be wrong or not remembering correctly, but I suggest checking it out first. Apparently solid state is real touchy. -- Jim Aeschliman bb840@scn.org Black Diamond, Washington KD7MK From lwbyppp@epix.net Sat Mar 16 15:22:12 1996 From: rheiss@tuba.aix.calpoly.edu (Robert Everitt Heiss) Newsgroups: rec.radio.amateur.antenna Subject: Re: RG6, 58,59 Cable Data Date: 13 Mar 1996 22:40:23 -0800 Message-ID: <4i8f0n$213b@tuba.aix.calpoly.edu> References: <4i28tk$ggq@senator-bedfellow.MIT.EDU> In article <4i28tk$ggq@senator-bedfellow.MIT.EDU>, Chris Farrell wrote: > >The following information was extracted from the Times Fiber Communications, [...] >Dielectric Material for all the above cables is Polyethylene Solid PE dielectric in RG6 and RG59, that's interesting. All the suppliers around here sell foam dielectric RG6 and RG59. I have noticed both solid and foam cable labeled RG8, both foam and semi-solid RG62 as well. Buyer beware. I started to notice the dielectrics after learning to use Q sections and stubs for antenna matching, where velocity factor is important. The Times coax you described has VF=.66 which is typical of solid PE. Here is the formula I used to determine VF from impedance Z ohms and capacitance C pf/ft: VF=1016/(Z*C) The dielectric also determines the center conductor size for the desired impedance. The center conductor for foam is larger than for solid PE, and since most of the loss is due to skin resistance of the center conductor, foam-type coax should have lower loss than solid PE. Power and peak voltage handling is generally much higher with solid dielectric than with foam. The cost-effective RG8X and RG59 foam types, which aren't rated to handle a kilowatt plus, are never recommended by ham authorities. The mechanical properties of the dielectric could also be important. Foam coax is lighter than it looks, an advantage for portable stations. Solid PE dielectric is more resistant to abuse such as soldering heat, stepping on it, or tightly coiling it into a choke. Coax is so simple -- only four parts, and we just discussed one -- okay, off the soapbox for now. 73, Rob KO6KA rheiss@tuba.calpoly.edu P.S. Food for thought: golf balls have dimples; hardline is corrugated. From lwbyppp@epix.net Sat Mar 16 15:22:13 1996 From: derek.scherer@rmin.net (Derek Scherer) Newsgroups: rec.radio.amateur.antenna Subject: Re: Rombic Ant Date: Wed, 13 Mar 1996 19:36:00 GMT Message-ID: <9603140218323723@rmin.net> Distribution: world I'm looking for info to build a Rombic ant for TV or HF --- * OLX 2.2 TD * It's only a hobby ... only a hobby ... only a From lwbyppp@epix.net Sat Mar 16 15:22:14 1996 From: sabinw@crpl.cedar-rapids.lib.ia.us (Bill W0IYH) Newsgroups: rec.radio.amateur.antenna Subject: s meters Date: 11 Mar 1996 14:23:00 GMT Distribution: world Message-ID: <4i1d04$pmu@flood.weeg.uiowa.edu> Reply-To: SABINW@crpl.cedar-rapids.lib.ia.us A calibrated S meter, in a rcvr whose gain and AGC properties are accurately known (within a couple of dB or so), would provide information that many operators will learn to utilize, once it is available and trustworthy. The ability to measure weak signals and noise levels with fair accuracy and *precision* gives a rcvr a certain instrumentation capability. If it can be done easily and economically there can't be all that much wrong with it. Radio amateurs are becoming more sophisticated as technology becomes more sophisticated. They will welcome the chance to get better quantitative evaluations. One quick example might be the evaluation of an HF data channel in the presence of noise and fading. From lwbyppp@epix.net Sat Mar 16 15:22:15 1996 From: w8jitom@aol.com (W8JI Tom) Newsgroups: rec.radio.amateur.antenna Subject: Re: Shielded Coax Pair Dipole Feed Date: 12 Mar 1996 08:42:53 -0500 Message-ID: <4i3v0t$h5u@newsbf02.news.aol.com> References: <4i3799$c5j@crash.microserve.net> Hi Ron, rvr@pacifier.com (Ron Ries) wrote: > >When using a pair of coax to feed a dipole, i.e., using the center >conductors in each coax as a differential feeder (also using a 4:1 >balun), OK, that doubles the loss when the system is matched in both cases. > . . . I am concerned about the loading on 20 where the Rr is >approximately 4Kohms and high SWR. Rr is a hundred ohms or so. The *feedpoint* R is a few thousand ohms. Losses in the feeder will be very high. I'd worry also! >BTW, I am using a tuner with this setup. Why do you want to use that feeder? Why not open wire line? 73 Tom From lwbyppp@epix.net Sat Mar 16 15:22:16 1996 From: rvr@pacifier.com (Ron Ries) Newsgroups: rec.radio.amateur.antenna Subject: Shielded Coax Pair Dipole Feed Date: 12 Mar 1996 02:13:20 GMT Message-ID: <4i2mk1$8a3@news.pacifier.com> When using a pair of coax to feed a dipole, i.e., using the center conductors in each coax as a differential feeder (also using a 4:1 balun), does one gain the advantage of half the lossiness of a single coax in a non-resonant configuration and twice the resistance to breakdown with SWR of greater than 5? The example is called the "Spencer" antenna mentioned in Lew McCoy's antenna book. The dipole is cut for 40-about 32.5 ft. per side and works fine on 40 eliminating a lot of the local QRN but I am concerned about the loading on 20 where the Rr is approximately 4Kohms and high SWR. BTW, I am using a tuner with this setup. Any comments or suggestions? -- Arizona Dreamin' From lwbyppp@epix.net Sat Mar 16 15:22:17 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: Shielded Coax Pair Dipole Feed Date: Tue, 12 Mar 96 06:53:44 GMT Message-ID: <4i3799$c5j@crash.microserve.net> References: <4i2mk1$8a3@news.pacifier.com> rvr@pacifier.com (Ron Ries) wrote: >When using a pair of coax to feed a dipole, i.e., using the center >conductors in each coax as a differential feeder (also using a 4:1 >balun), > . . . I am concerned about the loading on 20 where the Rr is >approximately 4Kohms and high SWR. > >BTW, I am using a tuner with this setup. I haven't seen the article this appeared in, but it sounds reasonable to expect good performance as long as the antenna is resonant. The problem when you use it on 20M isn't so much the feedline, it's the fact that now you're driving a very high impedance antenna system with a balun that's not designed to work into that type of load. With a 4K ohm load, it's extremely unlikely the balun is performing properly. At best, it's probably losing balance. At worst, it's consuming a significant percentage of your transmitter's power. In general, there are only two efficient configurations of balanced feeder antenna systems - those that present the balun with an impedance within the proper range, and those that are tuned with a balanced L/C network (not a balun). 73, Jack WB3U From lwbyppp@epix.net Sat Mar 16 15:22:18 1996 From: w8jitom@aol.com (W8JI Tom) Newsgroups: rec.radio.amateur.antenna Subject: Re: Shielded Coax Pair Dipole Feed Date: 15 Mar 1996 10:23:19 -0500 Message-ID: <4ic217$c8t@newsbf02.news.aol.com> References: <31470AE8.48D3@arrl.org> In article <31470AE8.48D3@arrl.org>, Zack Lau writes: > >Measurements and computer simulations I've done seem to >indicate little difference in loss with matched transmission >lines, assuming you accurately match the electrical lengths. > >Zack KH6CP/1 What you say is absolutely true, if the line is matched the loss is the same....no better no worse. I corrected it. I hope it got posted. 73 Tom From lwbyppp@epix.net Sat Mar 16 15:22:19 1996 From: kovar@zeus.ia.net (Jack Kovar KE0AX) Newsgroups: rec.radio.amateur.antenna Subject: Should I buy: Cushcraft ARX-270 antenna? Date: 12 Mar 1996 19:03:38 GMT Message-ID: <4i4hqb$ncm@hera.ia.net> ARX-270 Cushcraft 70cm/2mtr base antenna. Rated at 12db/9db gain uhf/vhf. Are these figures the dbd or the tricking dbi references? I would like to here from anyone that has installed and used this Dualband base station antenna. I have already ordered it and hoping for positive but honest comments. Does it have dc grounded coupling for static and lightning protection? Setting the money cost aside for now what is the best omni highgain dualband antenna offered to the Ham market? If you are also wondering about this antenna then give me a month to install it and email me for a comparison to my existing ringo 1 antenna. I have been very happy with my HF Antenna A3S and hope the ARX-270 will fullfill my needs too. Please reply with comments to: Jack Kovar ke0ax@ia.net THANKS, Jack From lwbyppp@epix.net Sat Mar 16 15:22:20 1996 From: Timothy E. Nagle Newsgroups: rec.radio.amateur.antenna Subject: Re: shuttle communication on 2 meter Date: 13 Mar 1996 17:11:59 GMT Message-ID: <4i6vkv$mi9@bb6k35.BB.Unisys.Com> What kind of report did you get back? Have you made many contacts? Just curious, Tim From lwbyppp@epix.net Sat Mar 16 15:22:21 1996 From: Jake Middlebrook Newsgroups: rec.radio.amateur.antenna Subject: Re: Strange Phenonomon on G5RV Date: Mon, 11 Mar 96 19:20:40 -0500 Message-ID: References: <4h3433$2nb@news.fwi.com> <1996Mar1.151643.22032@ke4zv.atl.ga.us> you may have run into something Tesla discribed as standing waves in the earth . He reported lighting as electrically detected waxing and waneing as thunderstorms moved off he belived he was seeing standing waves which were being set up in the ea rth as a large but finite object reguardless the effect is real take the advice of someone from the thunder storm capatol of the world orlando and ground that antenna if you even think a storm might come by sometime soon goodluck Jake From lwbyppp@epix.net Sat Mar 16 15:22:22 1996 From: raiar@inlink.com (Gary V. Deutschmann, Sr.) Newsgroups: rec.radio.amateur.antenna Subject: Re: Super J-Pole antenna Date: Thu, 14 Mar 1996 14:52:39 GMT Message-ID: <4i9bdi$p6o@news1.inlink.com> References: <4ho8js$881@ns1.thpl.lib.fl.us> kwhite@scfn.thpl.lib.fl.us (Ken White) wrote: >Just built myself a nifty 2-meter J-Pole antenna called the "Copper >Cactus", but I hear that there is another one called the "Super J-Pole" >that might be a little better. Better or not, I'd like to build one. >Trouble is - I can't find the construction details. >Has anyone run across this antenna? >Thanks, Ken - KE4WIS Pictures someday maybe! Hi Ken Besides the Copper Cactus J-Poles on my home page, I also have Stacked-Js and Mirror Image Js... The Stacked J is 1-1/4 wavelengths tall overall and the mirror image J is 1-1/2 wavelengths long. By using spring steel stainless wire, the antenna can be made almost invisible or even go mobile... http:/www.inlink.com/~raiar/amateur.html Gary From lwbyppp@epix.net Sat Mar 16 15:22:22 1996 From: jbenson@inmind.com (john d benson) Newsgroups: rec.radio.amateur.antenna Subject: test Date: Thu, 14 Mar 96 00:22:49 GMT Message-ID: <4i7sjo$hjl@mujibur.inmind.com> test From lwbyppp@epix.net Sat Mar 16 15:22:23 1996 From: Rick Wilson Newsgroups: rec.radio.amateur.antenna Subject: test - ignore Date: 12 Mar 1996 12:41:09 GMT Message-ID: <4i3rd5$664@babylon5.glenqcy.glenayre.com> test - ignore -- Rick Wilson | e-mail: rdw@glenqcy.glenayre.com fax 217 221 6259 | voice 217 221 6137 | ham call W0KT se habla espan~ol | ich spreche deutsch | si parla italiano From lwbyppp@epix.net Sat Mar 16 15:22:25 1996 From: kr4tg@mindspring.com (mike del pozzo) Newsgroups: rec.radio.amateur.antenna Subject: Re: Tower Guy Spacing Date: Tue, 12 Mar 1996 12:00:45 GMT Message-ID: <4i3p1h$a25@firebrick.mindspring.com> References: <4hpihd$r8i@kelly.iaonline.com> kg9cc@iaonline.com (Jim Rowley) wrote: >Hello all. This is my first time posting so I hope I do it right. >I remember reading somewhere that if you are limited on space that >you can reduce the distance from the tower base to guy anchor point >from the recomended 80% of tower height to something like 50% by >going to 4 guys spaced 90 degrees. Rohn shows this in their catalog >but only for the foldover towers. I plan to install 70ft of Rohn 45G >and would like to space the guy anchors between 35 and 40 ft from the >base. Anyone out there know about this or has used this method? >Thanks and 73 >Jim, KG9CC Hello Jim, yup , I have a 70 ft. Rohn 25 W/ a 4 el Quad on top . Previously had all three Hygain Long Johns on top ( 5 el. 10/15/20 beams). It seems to be a nice arrangement , especially if ground space is somewhat limited. My guys are at 90 deg. intervals and located at 20ft , 40ft , and 65 ft. The material used is of 5/16 dia stranded . The tower has been hit with better than 70 MPH wind with the beams on top and did not even budge. I will suggest however that you put some serious work into the guy anchors ( cement embedded screw anchors or similliar ). My anchor points are 45 & 50 feet from the base and are the above arrangement. Gud luck es 73 de KR4TG ,Mike From lwbyppp@epix.net Sat Mar 16 15:22:26 1996 From: w7el@teleport.com (Roy Lewallen) Newsgroups: rec.radio.amateur.antenna Subject: Re: W6KKT VISALIA HF MOBILE ANTENNA "SHOOTOUT" INFO Date: Mon, 11 Mar 96 19:16:29 GMT Message-ID: <4i1u4i$rjq@nadine.teleport.com> References: <4hc0ac$leq@ns.kern.com> <4hhego$8np@newsbf02.news.aol.com> <4i13pu$128@ionews.ionet.net> In article <4i13pu$128@ionews.ionet.net>, Hank Blackstock wrote: >bart@wb6hqk.ampr.org (Bart Rowlett) wrote: > ;>The purpose of the contest is to compare the DX performance of various 75M ;>mobile antenna installations by measuring the ratio of low angle vertically ;>polarized radiation to the power actually delivered to the antenna. Power ;>delivered to the antenna is assumed to be the difference between the measured ;>forward and reverse power indicated with a Bird wattmeter. ;Where did they come up with that assumption? Someone needs to ;read Reflections by M. Walter Maxwell, W2DU. If they use this ;method it is going to give the bugcatcher guys an even greater ;advantage (if they put their matching network at the ;transmitter rather than the antenna). Could you please direct us to the place in Walt's book where it says that this isn't a valid way to measure power? Roy Lewallen, W7EL From lwbyppp@epix.net Sat Mar 16 15:22:27 1996 From: Garry Foster Newsgroups: rec.radio.amateur.antenna Subject: Re: W6KKT VISALIA HF MOBILE ANTENNA "SHOOTOUT" INFO Date: Tue, 12 Mar 1996 11:18:22 -0800 Message-ID: <3145CDFE.545E@cpcnet.com> References: <4hc0ac$leq@ns.kern.com> <4hhego$8np@newsbf02.news.aol.com> <4i13pu$128@ionews.ionet.net> <4i1u4i$rjq@nadine.teleport.com> Roy Lewallen wrote: > In article <4i13pu$128@ionews.ionet.net>, Hank Blackstock wrote: >bart@wb6hqk.ampr.org (Bart Rowlett) wrote: > > ;>The purpose of the contest is to compare the DX performance of various > 75M > ;>mobile antenna installations by measuring the ratio of low angle > vertically > ;>polarized radiation to the power actually delivered to the antenna. > Power > ;>delivered to the antenna is assumed to be the difference between the > measured > ;>forward and reverse power indicated with a Bird wattmeter. > > ;Where did they come up with that assumption? Someone needs to > ;read Reflections by M. Walter Maxwell, W2DU. If they use this > ;method it is going to give the bugcatcher guys an even greater > ;advantage (if they put their matching network at the > ;transmitter rather than the antenna). > > Could you please direct us to the place in Walt's book where it says that > this isn't a valid way to measure power? > > Roy Lewallen, W7EL Well If I remimmber right Walt says that all the power gets radiated after it bounces atound enough. Minus feed line loses of course but I don't remimber what he says about indicated power. Or is indicated power on a Bird real power. Actually this brings me back to a point that is made in a series of HP tapes I saw, that would say that the feed line on a mobile at 80 meters is not a transmission line and therefore transmission line theory doesn't apply. The simple statement was that "Transmission line rules don't apply untill you have a transmissiom line. To have a transmission line it has to be long enough that the signal is flowing in both directions at the same time.(ie. 1/8 wavelength minimum.)" Anything under this length is just a lead and measuring instruments based on the lines charistic impedence are of no use, and you have to use e,i,and phase angle measurements to determine what is going on. However the article in QST about on of the shootouts showed antennas winning that should acording to antenna lore. From lwbyppp@epix.net Sat Mar 16 15:22:29 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: W6KKT VISALIA HF MOBILE ANTENNA "SHOOTOUT" INFO Date: Tue, 12 Mar 96 20:09:37 GMT Message-ID: <4i4ltr$f2d@crash.microserve.net> References: <4hc0ac$leq@ns.kern.com> <4hhego$8np@newsbf02.news.aol.com> Cecil Moore wrote: >Bart Rowlett writes: > >>the near field remaining at the test distance. Since the antenna >>heights are all about the same (13.5 feet maximum), it is assumed >>the near field > >Is there any limit on length of the antenna as long as the 13.5 ft >height limit is observed? Could the antenna, for instance, be a 40 ft >loop from front bumper to rear bumper as long as it didn't get above >13.5 ft in height? How about the diameter of the mast? Would it be permissable to be, say, slightly larger that the diameter of a 3-500Z? I've heard large masts like that often result in much greater field strength, although no one's sure exactly why. ;) Cecil, if you'll bring a loop, I'll bring two of my "super efficient" masts to support it. Say, what's the prize for winning this shootout? 73, Jack WB3U From lwbyppp@epix.net Sat Mar 16 15:22:31 1996 Newsgroups: rec.radio.amateur.antenna From: gary@ke4zv.atl.ga.us (Gary Coffman) Subject: Re: W6KKT VISALIA HF MOBILE ANTENNA "SHOOTOUT" INFO Message-ID: <1996Mar12.192810.17705@ke4zv.atl.ga.us> Reply-To: gary@ke4zv.atl.ga.us (Gary Coffman) References: <4hc0ac$leq@ns.kern.com> <4hhego$8np@newsbf02.news.aol.com> <4i13pu$128@ionews.ionet.net> <4i1u4i$rjq@nadine.teleport.com> <3145CDFE.545E@cpcnet.com> Date: Tue, 12 Mar 1996 19:28:10 GMT In article <3145CDFE.545E@cpcnet.com> Garry Foster write s: >Roy Lewallen wrote: > > In article <4i13pu$128@ionews.ionet.net>, > Hank Blackstock wrote: > >bart@wb6hqk.ampr.org (Bart Rowlett) wrote: > > ;>The purpose of the contest is to compare the DX performance of various > > 75M > > ;>mobile antenna installations by measuring the ratio of low angle > > vertically > > ;>polarized radiation to the power actually delivered to the antenna. > > Power > > ;>delivered to the antenna is assumed to be the difference between the > > measured > > ;>forward and reverse power indicated with a Bird wattmeter. > > ;Where did they come up with that assumption? Someone needs to > > ;read Reflections by M. Walter Maxwell, W2DU. If they use this > > ;method it is going to give the bugcatcher guys an even greater > > ;advantage (if they put their matching network at the > > ;transmitter rather than the antenna). > > > > Could you please direct us to the place in Walt's book where it says that > > this isn't a valid way to measure power? > >Well If I remimmber right Walt says that all the power gets radiated after it >bounces atound enough. Minus feed line loses of course but I don't remimber >what he says about indicated power. Or is indicated power on a Bird real >power. Walt's right about all the power getting radiated (minus line losses), but you're misinterpreting what you read with the Bird. The *forward* power that you read on a line with non-unity VSWR will be *greater* than the power output of the transmitter due to the way the forward and reflected waves interact on the line. When you subtract the reverse power reading (also fictitious) you'll have the net power output of the transmitter, IE the actual power out. All of that, again minus line losses and antenna efficiency losses, will be radiated by the antenna. >Actually this brings me back to a point that is made in a series of HP >tapes I saw, that would say that the feed line on a mobile at 80 meters is >not a transmission line and therefore transmission line theory doesn't apply. >The simple statement was that "Transmission line rules don't apply untill you >have a transmissiom line. To have a transmission line it has to be long >enough that the signal is flowing in both directions at the same time.(ie. >1/8 wavelength minimum.)" I don't think they have a leg to stand on saying that. It's true that a standing wave needs a place to stand, but it can stand on tippy toe, so it doesn't need a big hulking length of line. In fact, only the little bit inside the meter is what's measured. To prove that, you only have to place a 100 ohm resistor on the output connector of the meter, and you'll read a 2:1 VSWR with *no* line present other than the little section inside the meter. Gary -- Gary Coffman KE4ZV | You make it, | Due to provider problems Destructive Testing Systems | we break it. | with previous uucp address es 534 Shannon Way | Guaranteed! | Email to ke4zv@radio.org Lawrenceville, GA 30244 | | From lwbyppp@epix.net Sat Mar 16 15:22:32 1996 From: Cecil Moore Newsgroups: rec.radio.amateur.antenna Subject: Re: W6KKT VISALIA HF MOBILE ANTENNA "SHOOTOUT" INFO Date: Mon, 11 Mar 96 21:07:58 -0500 Message-ID: References: <4hc0ac$leq@ns.kern.com> <4hhego$8np@newsbf02.news.aol.com> Bart Rowlett writes: >the near field remaining at the test distance. Since the antenna heights >are all about the same (13.5 feet maximum), it is assumed the near field Is there any limit on length of the antenna as long as the 13.5 ft height limit is observed? Could the antenna, for instance, be a 40 ft loop from front bumper to rear bumper as long as it didn't get above 13.5 ft in height? thanks and 73, Cecil, KG7BK, OOTC From lwbyppp@epix.net Sat Mar 16 15:22:34 1996 From: w7el@teleport.com (Roy Lewallen) Newsgroups: rec.radio.amateur.antenna Subject: Re: W6KKT VISALIA HF MOBILE ANTENNA "SHOOTOUT" INFO Date: Wed, 13 Mar 96 13:20:37 GMT Message-ID: <4i6i1b$g92@nadine.teleport.com> References: <4hc0ac$leq@ns.kern.com> <4hhego$8np@newsbf02.news.aol.com> <4i4ltr$f2d@crash.microserve.net> Some things take a while to sink in. (Actually, more and more are taking longer and longer. . .) Did I hear that the measurement was done with a magnetic field detector in the near field? And did someone ask if a loop (e.g., a whip top connected back to the car) was allowed? A setup like that ought to put out a terrifically big magnetic near field compared to a whip, even if the far field intensity were the same, if it was oriented right. Also, I wonder how much influence the shape of the car body has on the near field impedance (the ratio of E/H)? Some car bodies might do better than others. Sounds like an interesting modeling project if I ever get time. . . Roy Lewallen, W7EL From lwbyppp@epix.net Sat Mar 16 15:22:35 1996 From: w8jitom@aol.com (W8JI Tom) Newsgroups: rec.radio.amateur.antenna Subject: Re: W6KKT VISALIA HF MOBILE ANTENNA "SHOOTOUT" INFO Date: 14 Mar 1996 12:44:36 -0500 Message-ID: <4i9lu4$h7q@newsbf02.news.aol.com> References: <4i4ltr$f2d@crash.microserve.net> In article <4i4ltr$f2d@crash.microserve.net>, jackl@pinetree.microserve.com (WB3U) writes: > >How about the diameter of the mast? Would it be permissable to be, >say, slightly larger that the diameter of a 3-500Z? I've heard large >masts like that often result in much greater field strength, although >no one's sure exactly why. ;) > >Cecil, if you'll bring a loop, I'll bring two of my "super efficient" >masts to support it. Say, what's the prize for winning this shootout? > >73, >Jack WB3U If I was going to do that, I'd use a thin mast with a very large hat at the tip. Current distribution over the mast would be even, and the radiation resistance would be the highest value possible. If I wanted to have a weaker signal, I'd use a thicker mast with the same size hat. ;-) 73 Tom From lwbyppp@epix.net Sat Mar 16 15:22:36 1996 From: Kevin Schmidt Newsgroups: rec.radio.amateur.antenna Subject: Re: W6KKT VISALIA HF MOBILE ANTENNA "SHOOTOUT" INFO Date: 12 Mar 1996 19:50:31 GMT Message-ID: <4i4ki7$m52@theory.tc.cornell.edu> References: <4hc0ac$leq@ns.kern.com> <4hhego$8np@newsbf02.news.aol.com> <4i13pu$128@ionews.ionet.net> <4i1u4i$rjq@nadine.teleport.com> <3145CDFE.545E@cpcnet.com> Garry Foster wrote: >Actually this brings me back to a point that is made in a series of HP >tapes I saw, that would say that the feed line on a mobile at 80 meters is >not a transmission line and therefore transmission line theory doesn't apply. >The simple statement was that "Transmission line rules don't apply untill you >have a transmissiom line. To have a transmission line it has to be long >enough that the signal is flowing in both directions at the same time.(ie. >1/8 wavelength minimum.)" > >Anything under this length is just a lead and measuring instruments based on >the lines charistic impedence are of no use, and you have to use e,i,and >phase angle measurements to determine what is going on. > This is not correct. The only time the standard transmission line rules don't apply is if there are other modes besides the standard TEM ones. For coax, the cutoff wave length is of order the circumference of the coax, for HF frequencies these other modes are severely attenuated on this same scale, so once the cable is longer than a few circumferences the standard rules apply just fine. Actually it is rather hard to excite the other modes so for even shorter lines the "rules" work fine. On the other hand the definition of a "lead" and the rules that it follows are unknown, at least to me. It is clear that you don't need to have a long transmission line if you simply derive the equations. While your at it, you will also see that the power output is the difference between the forward and reverse powers indicated on a directional coupler. Like Roy, I don't believe that Walt Maxwell got this wrong. Kevin Schmidt w9cf@ptolemy.la.asu.edu From lwbyppp@epix.net Sat Mar 16 15:22:38 1996 Newsgroups: rec.radio.amateur.antenna From: wa2ise@netcom.com (Robert Casey) Subject: Re: Wanted plans for 440 J-pole/300 ohm wire Message-ID: References: <4i0f2j$me1@mark.ucdavis.edu> Date: Wed, 13 Mar 1996 00:14:13 GMT In article <4i0f2j$me1@mark.ucdavis.edu> szhall@bullwinkle.ucdavis.edu (Jeff H all) writes: > I have plans for a 2 meter j-pole which is made from 300 Ohm TV lead..I >am looking for the same plans for a 440...I want to take it on a trip..I >have looked in all my antenna books and I can't find the >plans...Thanks..73es..Jeff All you really need do is take the 2M antenna dimensions and multuply them by the ratio 146/445 and that should get you pretty close. The width of the 300 ohm twinlead stays the same, just the lengths change. Don't forget the ferrite bead or a few turns of feedline coax at the feedpoint, to keep RF off the feedline. From lwbyppp@epix.net Sat Mar 16 15:22:39 1996 From: w7el@teleport.com (Roy Lewallen) Newsgroups: rec.radio.amateur.antenna Subject: Wanted: Low-band modeling case studies Date: Wed, 13 Mar 96 13:10:23 GMT Message-ID: <4i6he8$g92@nadine.teleport.com> I'm giving a talk on low-band antenna modeling at the Visalia DX convention next month, and would like a couple of case studies to use as illustrations. What I'm looking for is examples of antennas which were modeled, then constructed and tested. Ones that didn't work as predicted are of interest as well as ones that did. Or, an antenna that was modified based on modeling predictions then tested. I'll give full credit to the source unless anonymity is requested. Thanks! Roy Lewallen, W7EL w7el@teleport.com From lwbyppp@epix.net Sat Mar 16 15:22:40 1996 From: Michael J Wooding Newsgroups: alt.radio.scanner,alt.radio.pirate,rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc,rec.radio.scanner,rec.radio.shortwave,uk.radio.amateur Subject: Re: Weird Radio Problem Date: Sat, 16 Mar 1996 11:45:09 +0000 Distribution: world Message-ID: References: In article <4idjm1$f0c@madeline.INS.CWRU.Edu>, David Mark writes >What's happening is your radio is probably tuned to an FM station >near the upper end of the band (around 107-108mhz) and you're >probably under a flight path. When a plane is nearby (there's >that word again) and the pilot transmits on one of the lower >airline frequencies, your radio's less than discriminating tuner >picks it up. Whilst that is very feasible, due to the low powers transmitted by aircraft (RX levels of the order of less than -90dBm even with the sorts of aerials and masts etc., that we use in the CAA !) then I would imagaine that the aircraft must be relatively low when overflying his property to cause these signals to be strong enough to swamp the radio. Mike Michael J Wooding vhf-comm@g6iqm.demon.co.uk - CompuServe: 100441,377 WWW: http://www.eolas.co.uk/ag/vhfcomm.htm (hambits.htm & hamclip.htm) WWW: http://www.clearlight.com/~vhfcomm Tel: (0)1788 890365 Fax: (0)1788 891883 KM Publications, 5 Ware Orchard, Barby, Nr.Rugby, CV23 8UF, UK VHF Communications Magazine - Especially Covering VHF, UHF and Microwaves From lwbyppp@epix.net Sat Mar 16 15:22:42 1996 Newsgroups: rec.radio.amateur.antenna From: dstock@hpqmdla.sqf.hp.com (David Stockton) Subject: Where do S reports go to, anyway ? Message-ID: Date: Mon, 11 Mar 1996 12:59:49 GMT All this fuss over S meter readings... Most just get written onto cardboard then ignored... A few people want to change things and get some quantitative measurement of the effect of the change. This seems a reasonable enough request to me. Absolute calibration either of receiver and of receiving antenna are not necessary, though a TX end antenna change could affect the angle of approach and polarisation of the incoming signal which could make RX antenna characteristics affect the result. I usually have a decent spectrum analyser in the shack that I can use on the antenna or on the IF out of a receiver. With this, and an oscilloscope, I can make useful measurements of relative signal strength as well as modulation and keying, limited chiefly by the stability of propagation conditions. This doesn't seem to help with comparative reports as sometimes my "Your signal rose by 8.5 dB" gets met by "What's that in S-points ?" Everyone seems to want an S report, but so few seem to know just what they're worth.... I second Roy's plea for front end step-attenuators, though if the S-meters are anything to go by, if the manufacturers saw them as a competitive lead, we'd get them, but they'd see no need for any greater accuracy of the steps than our current S meters... Cheers David (hang on, if I switch the pre-amp on, I can give you a better report) GM4ZNX From lwbyppp@epix.net Sat Mar 16 15:22:43 1996 From: kg5u@hal-pc.org (Dale L. Martin) Newsgroups: rec.radio.amateur.antenna Subject: Re: Where do S reports go to, anyway ? Date: Tue, 12 Mar 1996 12:07:37 GMT Message-ID: <4i3pav$124@news.hal-pc.org> References: dstock@hpqmdla.sqf.hp.com (David Stockton) wrote: > All this fuss over S meter readings... Most just get written onto >cardboard then ignored... > A few people want to change things and get some quantitative >measurement of the effect of the change. This seems a reasonable enough >request to me. Absolute calibration either of receiver and of receiving >antenna are not necessary, though a TX end antenna change could affect >the angle of approach and polarisation of the incoming signal which could >make RX antenna characteristics affect the result. > I usually have a decent spectrum analyser in the shack that I can >use on the antenna or on the IF out of a receiver. With this, and an >oscilloscope, I can make useful measurements of relative signal strength >as well as modulation and keying, limited chiefly by the stability of >propagation conditions. This doesn't seem to help with comparative reports >as sometimes my "Your signal rose by 8.5 dB" gets met by "What's that in >S-points ?" > Everyone seems to want an S report, but so few seem to know just what >they're worth.... > I second Roy's plea for front end step-attenuators, though if the >S-meters are anything to go by, if the manufacturers saw them as a >competitive lead, we'd get them, but they'd see no need for any greater >accuracy of the steps than our current S meters... > Cheers > > David (hang on, if I switch the pre-amp on, I can give you a better >report) GM4ZNX David, Maybe the manufacturers will see it as a marketing opportunity and include a digital readout adjacent to or within the face of the analog meter. They could add a button and it would freeze the display so the operator would not forget what it was. As to your question: "Where do S reports go to, anyway?" I don't know if things are that much different in Scotland, but here in the U.S.A., there is probably not a ham among us who doesn't know from grade school that there is what is called a 'permanent' record. Everything you ever do in your life goes into your 'permanent' record. I can't recall the number of times the threat of something I did or was planning to do going into my 'permanent' record at school was used by a teacher or the principal. Of course, it was a real letdown to find out that there was no such thing....Oh, the lost opportunities to do some neat things but didn't for fear of it going into your permanent record!! Anyway, I suspect if S reports had to go somewhere, that's where they would go, right? 73 and have fun!!! Dale Houston, TX From lwbyppp@epix.net Sat Mar 16 15:22:44 1996 Newsgroups: rec.radio.amateur.antenna From: Dperrin Subject: Who makes HD Aluminum towers? Message-ID: <3147B8EA.57D6@CONKNET.COM> Date: Wed, 13 Mar 1996 22:12:58 -0800 Hi: Who makes good quality heavy duty aluminum towers? I am trying to replace one 50 foot tall that has a base 20" per leg. Thanks for any info or leads. Dave From lwbyppp@epix.net Sat Mar 16 15:22:46 1996 From: graham@southlin.demon.co.uk (Graham Seale) Newsgroups: rec.radio.amateur.antenna Subject: Re: Why long wire TVI Date: Thu, 07 Mar 1996 23:26:14 GMT Distribution: world Message-ID: <19960307.232614.94@southlin.demon.co.uk> References: <19960306.083826.89@southlin.demon.co.uk> <4hm1oc$255@newsbf02.news.aol.com> Reply-To: graham@southlin.demon.co.uk In message <4hm1oc$255@newsbf02.news.aol.com> W8JI Tom wrote: > Hi Graham, > > In article <19960306.083826.89@southlin.demon.co.uk>, > graham@southlin.demon.co.uk (Graham Seale) writes: > > >The trouble is a coax is an unbalanced structure,(snips) > > The problem is just as large with balanced line. Coax or open wire, BOTH > lines require equal and 180 degree out of phase currents on the conductors > to prevent radiation. > > Assuming that rule is followed at the load and source, *and coax is not > subject to field induced currents*, we can do anything we like to the > outside of the braid without changing the internal current balance. We can > run the coax underground, against other conductors, and through the fish > tank without upsetting the current balance inside the line. > > Not so with the balanced line. We have to keep that line several conductor > spacings away from other objects (even dielectrics) or be sure that the > external effect is applied equally to both conductors. And definitely out > of the fish tank. Hi Tom Tee Hee - I can just hear you quitting a ragchew ... "Gotta go fellas, the guppies are starting to pant and I'm steamin' up the shack - 73s" Yeah - I used to do that too. I made dozens of 50mm (err..2 inch) PVC conduit standoffs for my balanced line. (I favour 300 ohm or 450 ohm window slotted waxy polythene type.) But my experiences with balanced line do not mimic yours. For me, the TVI and "live" shack were instantly cured! We found that, within reason, you can treat it almost like coax. Sure I did a whole load of experiments with it - looking for leaks and fields, and I would not tape it hard up against a metal mast, or try to bury it! Yet it is surprisingly tolerant. You can hang it up a mast and if it touches a few places, it will not matter unless you are doing something else to seriously unbalance it. I even stapled the stuff straight across a cellar ceiling, then through a duct tube to the outside. I tried to keep it clear of other conductors, but it did not seem to care. Even through a pile coiled up in a heap on the patio, it was fine. I just made *very* sure that I fed it balanced, and I used common mode chokes to ensure it stayed that way. 73s G4WNT -- Graham Seale From lwbyppp@epix.net Sat Mar 16 15:22:47 1996 From: Cecil Moore Newsgroups: rec.radio.amateur.antenna Subject: Re: Windom comparisons Date: 15 Mar 1996 20:36:43 GMT Message-ID: <4ickcr$stt@itnews.sc.intel.com> References: <4ic6nh$2at@hp5.online.apple.com> n4lq@iglou.com (Steve Ellington) wrote: >Even a dipole has directional >qualities but not as severe as an 80 meter dipole or windom on 15 meters! >You will experience dead zones. ..and you will experience live zones. The four lobes on my 102ft dipole each has more gain than a resonant dipole on any HF band above 20m. If one understands radiation patterns, one can turn it into an advantage. I have the four lobes aimed at the world's land masses while the dead zones are aimed mostly at open water. >: I'm considering putting up a windom-type antenna, >:Finally, any comparisons between these type antennas and a G5RV? IMO, an antenna should start radiating at its highest point. That usually means a balanced antenna. My 102ft dipole has a low SWR and low losses and is resonant on all HF Ham frequencies. Radio Adventure is publishing a series of articles on the subject. 73, Cecil, KG7BK, OOTC (not speaking for my employer) From lwbyppp@epix.net Sat Mar 16 15:22:48 1996 From: mtaintor@eworld.com (MTaintor) Newsgroups: rec.radio.amateur.antenna Subject: Windom comparisons Date: 15 Mar 1996 08:43:29 -0800 Message-ID: <4ic6nh$2at@hp5.online.apple.com> Reply-To: mtaintor@eworld.com (MTaintor) I'm considering putting up a windom-type antenna, ie an off-center fed dipole. I've seen three different companies that advertise them: Antennas West, Fritzel, and Radio Works. Has anyone done a comparison of these? Is there much difference between them? I do know that RadioWorks has a vertical radiator that is part of there antenna. Does that make much difference? Finally, any comparisons between these type antennas and a G5RV? Thanks for any info you can share about these antennas. 73, Mark, N0YRW From lwbyppp@epix.net Sat Mar 16 15:22:49 1996 From: Kent Winrich Newsgroups: rec.radio.amateur.antenna Subject: WTB:Kiwa Loop Date: Mon, 11 Mar 1996 16:39:54 -0800 Message-ID: <3144C7DA.82D@execpc.com> I am looking for someone that wants to sell a KIWA MW Loop. Anyone out there?? Kent Winrich Waukesha, WI From lwbyppp@epix.net Thu Mar 21 13:39:57 1996 From: w8jitom@aol.com (W8JI Tom) Newsgroups: rec.radio.amateur.antenna Subject: Re: "floating" the output of a tuner. Date: 12 Mar 1996 20:40:49 -0500 Message-ID: <4i5931$2rn@newsbf02.news.aol.com> References: <4i1lsf$6vj@hpcvsnz.cv.hp.com> In article <4i1lsf$6vj@hpcvsnz.cv.hp.com>, tomb@lsid.hp.com (Tom Bruhns) writes: >Depends on the configuration of the tuner. As Gary C pointed out, a >"T" (or for that matter any configuration with one terminal common >to both input and output) is "unbalanced". If you perfectly floated >the source as well as the tuner, the output could be "balanced". > > Hi Tom, It's important to remember if the center of the balanced network isn't connected to ground, there is either no or very little transformation of common mode voltages. So choking effectiveness of a current balun isn't improved by the move. If someone is going to go through all that grief, they might as well build a link coupled tuner and be done with it all! Then they could have unbalanced output and a choice of balanced voltage or balanced current outputs. 73 Tom From lwbyppp@epix.net Thu Mar 21 13:39:59 1996 From: dcole@weaver.guilford.k12.nc.us (Derrick Cole) Newsgroups: rec.radio.amateur.antenna Subject: "Hamstick" dipole troubles Date: 16 Mar 1996 17:49:59 GMT Message-ID: <4iev07$amc@inxs.ncren.net> Greetings! At the Charlotte HamFest last weekend, I purchased two 40M "HamStick" antennas (HF mobile whips?) consisting of a coiled mast and an extendable metal "whip", which, when adjusted, supposedly allow for tuning for a certain center frequency. I also bought a mounting bracket so as to create a dipole from the two 'sticks. Suffice to say, I've not had much luck. Initially, with the whips fully extended, I could only achieve 3+:1 across 40M except for the upper 30KHz, where I could get 1-8-2:1. Wanting a lower SWR in the lower 100KHz, I set out to actually read the confusing instructions about the whip and tuning for a certain frequency. Choosing a frequency of 7.1MHz, this implies an exposed whip length of 39". I cut both whips to 39.5" (39" of which was exposed), tightened everything up, tuned up on 7.1MHz, and now enjoy 5:1 SWR everywhere. Obviously, I've done something wrong. Can anyone offer ANY advice on such a contraption? Where might I obtain replacement whips (which were originally 48.25" long)? What should I do? Thanks and 73, Derrick From lwbyppp@epix.net Thu Mar 21 13:39:59 1996 From: Will Flor Newsgroups: rec.radio.amateur.antenna Subject: Re: "Hamstick" dipole troubles Date: 17 Mar 1996 00:33:28 GMT Message-ID: <4ifmko$ml5@news.inc.net> References: <4iev07$amc@inxs.ncren.net> n4lq@iglou.com (Steve Ellington) wrote: >No but when you do, let me know. I use Hamsticks on the van and have to >use small capacitors to bring the swr down. They go from the antenna to >ground right at the feed point. My understanding is that a shortend >antenna should have a very low impedance thus the need for the capacitor. >Perhaps the same is necessary on your dipole arrangement. Yes; the Hamstick or any other short vertical does indeed have a low impedance - much lower than 50 ohms. This is in contrast with a long random wire, which has a really high impedance. To tune a short vertical like a hamstick I use a random-wire antenna tuner *backwards* - i.e. I feed it through the "antenna" terminal and connect the "transciever" terminal to the antenna, achieving a similar effect to yours. 73 de Will KB9JTT willf@rrgroup.com From lwbyppp@epix.net Thu Mar 21 13:40:00 1996 Newsgroups: rec.radio.amateur.antenna From: n4lq@iglou.com (Steve Ellington) Subject: Re: "Hamstick" dipole troubles Message-ID: References: <4iev07$amc@inxs.ncren.net> Date: Sat, 16 Mar 1996 21:02:30 GMT No but when you do, let me know. I use Hamsticks on the van and have to use small capacitors to bring the swr down. They go from the antenna to ground right at the feed point. My understanding is that a shortend antenna should have a very low impedance thus the need for the capacitor. Perhaps the same is necessary on your dipole arrangement. : Wanting a lower SWR in the lower 100KHz, I set out to actually read the : confusing instructions about the whip and tuning for a certain frequency. : Choosing a frequency of 7.1MHz, this implies an exposed whip length of : 39". I cut both whips to 39.5" (39" of which was exposed), tightened : everything up, tuned up on 7.1MHz, and now enjoy 5:1 SWR everywhere. : Obviously, I've done something wrong. Can anyone offer ANY advice on such : a contraption? Where might I obtain replacement whips (which were originall y : 48.25" long)? What should I do? : Thanks and 73, : Derrick -- Steve Ellington N4LQ@IGLOU.COM Louisville, Ky From lwbyppp@epix.net Thu Mar 21 13:40:01 1996 From: Cecil Moore Newsgroups: rec.radio.amateur.antenna Subject: Re: "Hamstick" dipole troubles Date: Sat, 16 Mar 96 17:51:08 -0500 Message-ID: References: <4iev07$amc@inxs.ncren.net> Derrick Cole writes: >Obviously, I've done something wrong. Can anyone offer ANY advice on such >a contraption? Where might I obtain replacement whips (which were originally Don't know what you mean by 1-8-2:1 Doesn't sound reasonable for 1:1, 8:1, and 2:1 to all happen within 30KHz. First check continunity from base to stinger. Then check for no continunity from section to section. Then find out where the thing is resonant using a grid-dip meter or an unlocked transceiver. If you have the thing wired up properly, my guess is that you need longer stingers than came with the sticks. BTW, you need to tune it before you add transmission line to it. The transmission line itself can cause confusing readings. Good Luck. 73, Cecil, KG7BK, OOTC (not speaking for my employer) From lwbyppp@epix.net Thu Mar 21 13:40:02 1996 From: ksprouse Newsgroups: rec.radio.amateur.antenna Subject: Re: "Hamstick" dipole troubles Date: 17 Mar 1996 13:41:13 GMT Message-ID: <4ih4pp$aqr@harbour.awod.com> dcole@weaver.guilford.k12.nc.us (Derrick Cole) writes: > Greetings! > > At the Charlotte HamFest last weekend, I purchased two 40M "HamStick" antenn as > (HF mobile whips?) consisting of a coiled mast and an extendable metal "whip ", > which, when adjusted, supposedly allow for tuning for a certain center > frequency. I also bought a mounting bracket so as to create a dipole from > the two 'sticks. > > Suffice to say, I've not had much luck. Initially, with the whips fully > extended, I could only achieve 3+:1 across 40M except for the upper 30KHz, > where I could get 1-8-2:1. > > Wanting a lower SWR in the lower 100KHz, I set out to actually read the > confusing instructions about the whip and tuning for a certain frequency. > Choosing a frequency of 7.1MHz, this implies an exposed whip length of > 39". I cut both whips to 39.5" (39" of which was exposed), tightened > everything up, tuned up on 7.1MHz, and now enjoy 5:1 SWR everywhere. > > Obviously, I've done something wrong. Can anyone offer ANY advice on such > a contraption? Where might I obtain replacement whips (which were originall y > 48.25" long)? What should I do? > > Thanks and 73, > Derrick From lwbyppp@epix.net Thu Mar 21 13:40:04 1996 From: ksprouse Newsgroups: rec.radio.amateur.antenna Subject: Re: "Hamstick" dipole troubles Date: 17 Mar 1996 13:46:36 GMT Message-ID: <4ih53s$aqr@harbour.awod.com> dcole@weaver.guilford.k12.nc.us (Derrick Cole) writes: > Greetings! > > At the Charlotte HamFest last weekend, I purchased two 40M "HamStick" antenn as > (HF mobile whips?) consisting of a coiled mast and an extendable metal "whip ", > which, when adjusted, supposedly allow for tuning for a certain center > frequency. I also bought a mounting bracket so as to create a dipole from > the two 'sticks. > > Suffice to say, I've not had much luck. Initially, with the whips fully > extended, I could only achieve 3+:1 across 40M except for the upper 30KHz, > where I could get 1-8-2:1. > > Wanting a lower SWR in the lower 100KHz, I set out to actually read the > confusing instructions about the whip and tuning for a certain frequency. > Choosing a frequency of 7.1MHz, this implies an exposed whip length of > 39". I cut both whips to 39.5" (39" of which was exposed), tightened > everything up, tuned up on 7.1MHz, and now enjoy 5:1 SWR everywhere. > > Obviously, I've done something wrong. Can anyone offer ANY advice on such > a contraption? Where might I obtain replacement whips (which were originall y > 48.25" long)? What should I do? > > Thanks and 73, > Derrick Hi Derrick, I have encountered several problems where the "hamstick" antennas were not mounted with the insulating washer isolating the center lead-fed antenna from the ground or shield side of the coax. I would not overlook the simple fixes. As far as replacement whips, you can order them directly from the manufacturer in Anderson, SC...WD4BUM...Also I personally would not recommend trimming the whips, I would just slide them in or out for the proper adjustment. My experi ence with these antennas have been great considering the small investment that you have to make. GOOD LUCK!! and 73. Kellan Sprouse AD4QE From lwbyppp@epix.net Thu Mar 21 13:40:05 1996 From: aa5mt@gate.kc5aug.ampr.ORG Newsgroups: rec.radio.amateur.antenna Subject: (none) Date: 17 Mar 96 17:12:43 GMT Message-ID: <71722@gate.kc5aug.ampr.org> Reply-To: 44.42.200.20@gate.kc5aug.ampr.org Does the receiver range really equal the transmitter range of an antenna? ie...Are the receive and the transmit of an antenna reciprocal? As the size of the antenna decreases, the load factor increases. So, at full size(free space length), the load factor is 0, and for a zero length antenna(isotropic)the load factor is infinity. The transmit field strength is based on an area measurement of the cross section of the antenna field, at a given distance, giving a strength to distance figure. The receive measurement is based on the area cross- section of the antenna. The more 'capture area' the higher the received signal. In optics, it's called aperture. For a full size antenna with no shortening/loading, the receive cross- section gives a value which fulfills a formula meant to explain field strength. And yes, at full size(free space length), the receive and transmit strengths are truly reciprocal. The same number of stations heard can be contacted that can be heard. With a much shortened antenna, the area is less on receive, but on transmit almost the same field strength can be generated. So, for a station over the horizon, the S-meter reading is somewhat less than a half-wave full size dipole. As the size of the antenna approaches a point-source size(isotropic), the distant station will see the S-meter drop the equivalent of 2.13 db less than the dipole. At the shortened antenna station, transmit is somewhat better than receive. If you've used a Super/Iso loop antenna, this is very obvious. For the fully shortened antenna(isotropic), the station will hear zero stations, because he now has a capture area of zero. The transmit field strength becomes the -2.13 dbd received by the distant station. So, my conclusion about the reciprocal effect? Most of us use loaded beams or traps somewhere along the way. Any free space size dipoles? With that in mind, I would have to say... I don't think so. From lwbyppp@epix.net Thu Mar 21 13:40:06 1996 From: ve7rdl@ve7rdl.ampr.ORG Newsgroups: rec.radio.amateur.antenna Subject: (none) Date: 16 Mar 96 23:27:25 GMT Message-ID: <229@ve7rdl.ampr.org> subscribe ve7duc.ampr.org ham-ant From lwbyppp@epix.net Thu Mar 21 13:40:07 1996 From: efl@interaccess.COM (EFL) Newsgroups: rec.radio.amateur.antenna Subject: (none) Date: 14 Mar 96 08:50:54 GMT Message-ID: <199603140250.UAA14515@flowbee.interaccess.com> subscribe From lwbyppp@epix.net Thu Mar 21 13:40:08 1996 From: Martin Hibbs Newsgroups: rec.radio.amateur.antenna Subject: Re: 10 Mtr Yagi on a 40-2CD?? Date: 14 Mar 1996 20:09:19 GMT Message-ID: <4i9udf$tim@express.ior.com> References: -- Martin Hibbs --- A Subscriber at Internet On-Ramp, Inc. I laced three fairly closely spaced 10 meter elements on my Hygain 2 element 40 and it seemed to work just fine. I noticed no degradation on 40 (very slight VSWR change) and 10 meters performed as I expected. Ran it for 2 years before changing the entire antenna farm. Give it a try. You'll probably like it. Marty WB7RBJ From lwbyppp@epix.net Thu Mar 21 13:40:08 1996 From: pelt@vt.edu (Ranson J. Pelt) Newsgroups: rec.radio.amateur.antenna Subject: 10 Mtr Yagi on a 40-2CD?? Date: 12 Mar 1996 22:41:28 GMT Message-ID: Has anyone interlaced a 10 Mtr Yagi on a 40-2CD?? Would appreciate any comments from anyone who's tried this. Tnx -- Ranson Pelt pelt@vt.edu nz4i From lwbyppp@epix.net Thu Mar 21 13:40:09 1996 From: charlie@netdepot.com (Charlie Fortner) Newsgroups: rec.radio.amateur.antenna Subject: 2m antenna for travel Date: Mon, 18 Mar 1996 18:51:39 -0500 Message-ID: I am going on a trip with the local Boy Scout troop out west this summer and I want some opinions on what antenna(s) I should bring for the times we are in a building (a hotel of some sort). I have an Icom IC-T22A handheld with a Larsen 5/8 wave mag mount (to use on the van when we are mobile - I really don't want to have to take it off the van for use inside). I was thinking about making a J-Pole out of copper pipe and using that, but it would be bigger than I would like it to be. Any ideas, suggestions, or the like would be greatly appreciated. BTW - any mods for an IC-2000H would also be appreciated! Thanx! -- Ted Fortner Wozniac@netdepot.com KF4GJR From lwbyppp@epix.net Thu Mar 21 13:40:10 1996 From: Geir Newsgroups: rec.radio.amateur.antenna Subject: 6 meter high gain yagis Date: Fri, 15 Mar 1996 02:09:07 +0100 Message-ID: <3148C333.3D37@telepost.no> Hello and thanks for reading this. I am looking for addresses and prices for big 6 meter yagis. I have seen one 11 element yagi for sale in scandinavia. But the price is doubled compared to a 6 element from the same factory. The 11 el. is just not worth all the money they want for it. So I plan to import one from the U.S. If any of you have some infos i.e. addresses, numb. of elements, lenght, gain and prices, it will be really appreciated. 73 de Geir / LA6LU From lwbyppp@epix.net Thu Mar 21 13:40:11 1996 From: Simon gw7soz Newsgroups: rec.radio.amateur.antenna Subject: 6m beam dimensions?? Date: 17 Mar 1996 11:10:29 GMT Message-ID: <4igrv5$ia0@osfb.aber.ac.uk> Hi Does anyone have the dimensions for a 3 ele 6m beam?? 73 de Simon srj5@aber.ac.uk http://www.aber.ac.uk/~srj5 From lwbyppp@epix.net Thu Mar 21 13:40:12 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: >"floating" the output of a tuner Date: Sun, 17 Mar 96 15:17:30 GMT Message-ID: <4ihanf$pvl@crash.microserve.net> References: <4i4lp3$bhd@babylon5.glenqcy.glenayre.com> <4ic25e$809@chnews.ch.intel.com> Cecil Moore wrote: >I suspect, as long as the load remains resistive, a well-designed 4:1 >balun should work at even higher resistive loads. If I remember >right, inter-winding capacitance is the limiting factor with high >resistive loads. It depends on the frequency. On 160 and 80 meters, the problem usually relates to the inability of the device to maintain minimum required inductance relative to the load Z. On 40 meters and above, it's usually the interwinding capacitance that effects the transmformer as the load Z rises. These two characteristics also limit the frequency response of the device when it's driving the proper load. 73, Jack WB3U From lwbyppp@epix.net Thu Mar 21 13:40:13 1996 From: shssci@li.net Newsgroups: rec.radio.amateur.antenna Subject: adhesive copper tape Date: Sun, 17 Mar 96 11:45:35 PDT Message-ID: Greetings to all - Has anyone tried making an antenna or counterpoise from the self-adhesive copper foil tape intended for stained glass projects? It is "dead soft" copper with an adhesive backing. You can solder directly to it. This tape is the stuff they wrap around the border of each piece of glass to solder it to the next piece of glass. It comes in various widths - I think up to 1/2 inch, and in several thicknesses - thickest I saw in catalog was 1.5 mil. It comes in 36 yard rolls for around $5 - $7 a roll (cheaper in quantity, but 108 feet seems plenty of quantity!) It is intended to be soldered and the adhesive backing seems to hold up to the heat. Seems it might be an ideal material for appartments - stick it right to the wall (adds a whole new meaning to "ceiling beams"!) - and applications where you might want to make the antenna less obvious. My own application is installing a counterpoise system inside a fiberglass sail boat for an automatic antenna tuner working the 40M to 15M bands. (250W PEP?) The antenna is the backstay which, on my boat, puts the tuner in a bad spot for a direct-to-the-water ground of sufficient area. (Plus potential for electrolysis problems.) So, I'm going to use counterpoise system below water line. I don't want to use loose wires for that and attaching them or regular copper foil to the hull would be an adventure with all the structural stuff in the way. The self-adhesive feature might solve this, too. I would like to hear from anyone who has tried this stuff for an antenna or counterpoise, or has any _constructive_ suggestions about it. Thanks for your help - have fun 73 - KD2FT Frank Fitz... and the crew of the mighty Draco shssci@li.net P.S. If this turns out to be a good idea for anyone, thank my wife - she's the stained glass craftsperson. From lwbyppp@epix.net Thu Mar 21 13:40:14 1996 Newsgroups: rec.radio.amateur.antenna From: griffin@jgfl1.allcon.com (Jens Goerke) Subject: Re: adhesive copper tape Message-ID: References: Date: Mon, 18 Mar 1996 20:25:43 GMT shssci@li.net wrote: [...] > My own application is installing a counterpoise system inside a fiberglass > sail boat for an automatic antenna tuner working the 40M to 15M bands. (250 W > PEP?) The antenna is the backstay which, on my boat, puts the tuner in a bad > spot for a direct-to-the-water ground of sufficient area. (Plus potential f or > electrolysis problems.) So, I'm going to use counterpoise system below wate r > line. I don't want to use loose wires for that and attaching them or regula r > copper foil to the hull would be an adventure with all the structural stuff in > the way. The self-adhesive feature might solve this, too. [...] How about a metal rudder IMHO this would make a rather good ground connection. What about the keel? On smaller sailing boats they are usually made from lead, so that would be another possibility. Just my $.02, Jens, DB9LL -- Missing coffee error - operator halted. This message may not be distributed via the Microsoft Network. From lwbyppp@epix.net Thu Mar 21 13:40:15 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: adhesive copper tape Date: Mon, 18 Mar 96 08:42:33 GMT Message-ID: <4ij7v4$7b7@crash.microserve.net> References: shssci@li.net wrote: >It comes in 36 yard rolls for around $5 - $7 a roll (cheaper in >quantity, but 108 feet seems plenty of quantity!) I need a small quantity of 1/8" or 1/4" tape, but I had given up on the idea because of Newark's prices. Your quote is MUCH less expensive though, so now I'm aware that there might be a more affordable source. Do you know if this is available without the adhesive backing? 73, Jack WB3U From lwbyppp@epix.net Thu Mar 21 13:40:18 1996 From: Cliff Soderback Newsgroups: rec.radio.amateur.antenna Subject: Re: adhesive copper tape Date: Wed, 20 Mar 1996 18:56:53 -0800 Message-ID: <3150C575.201B@cris.com> References: To: shssci@li.net shssci@li.net wrote: > > In Article, write: > > Newsgroups: rec.radio.amateur.antenna > > Path: li.net!news5.ner.bbnplanet.net!news.ner.bbnplanet.net!howland.reston .ans.net!Germany.EU.net!Frankfurt.Germany.EU.net!news.maz.net!news.allcon.net! jgfl1 > > From: griffin@jgfl1.allcon.com (Jens Goerke) > > Subject: Re: adhesive copper tape > > X-Newsreader: TIN [version 1.2 PL2] > > Organization: Private Multi-Site > > Message-ID: > > References: > > Date: Mon, 18 Mar 1996 20:25:43 GMT > > Lines: 23 > > > > shssci@li.net wrote: > > [...] > > > My own application is installing a counterpoise system inside a fibergla ss > > > sail boat for an automatic antenna tuner working the 40M to 15M bands. (250W > > > PEP?) The antenna is the backstay which, on my boat, puts the tuner in a bad > > > spot for a direct-to-the-water ground of sufficient area. (Plus potenti al for > > > electrolysis problems.) So, I'm going to use counterpoise system below water > > > line. I don't want to use loose wires for that and attaching them or re gular > > > copper foil to the hull would be an adventure with all the structural st uff in > > > the way. The self-adhesive feature might solve this, too. > > [...] > > > > How about a metal rudder > > IMHO this would make a rather good ground connection. > > What about the keel? On smaller sailing boats they are usually made > > from lead, so that would be another possibility. > > > > Just my $.02, > > Jens, DB9LL > > -- > > Missing coffee error - operator halted. > > > > This message may not be distributed via the Microsoft Network. > > de KD2FT > > Hi, Jens - thanks for the thoughts on grounding. Normally, these would > be worthy possibilities, but the specifics of my boat preclude me from > making effective electrical contact with either. > > In building my boat (35' double-ended cutter, 6' draft), I had to cast my > own keel. It is 6300 pounds of lead, but it is all internal, down in the > molded fiberglass keel cavity. To manage that job, I cast it in three layer s > of many separate blocks each. Each block was carefully cast to match the > shape of the keel cavity at the place where that block would go, and in a si ze > that I could carry up into the boat and back down into the hull (no internal > structures yet) and position properly in the keel cavity, without getting > killed. These blocks run about 100 to 150 pound each. After a layer of > blocks was positioned, I "potted" the blocks in resin and than fiberglassed > over the whole layer as both a securing agent for that layer, a base for the > next layer and to form a water-tight layer in the (hopefully unlikely) event > that I ground the boat and cause the existing bottom of the fiberglass keel to > leak. Then the next layer was cast, installed, potted and glassed over, etc . > The net result is that the keel is now composed of many separate and > electrically isolated blocks. > > As for the rudder, I also made that. It has a large, very rugged "core" of > stainless plate and the rudder stock, but it is inside a fiberglass shell > filled with microballoons. The rudder stock runs through a trunk made of > fiberglass tube from the hull to deck-level. At deck-level, it enters the > tiller-head. It would probably be OK as a capacitively-coupled ground, but > the result here is that it, too, is electrically unaccessable. The only > moving connection I could envision would be some kind of brush or wiper > contacting the rudder stock through the fiberglass rudder trunk. I don't > think this would be a good connection for long. > > Net result is that I believe I have to consider another method than the rudd er > or the balast. That leads me to the counterpoise system, and thence to the > installation problems of regular (wide) copper foil, now that all the interi or > structures and systems are in the way. There-in lies the reason for inquiri ng > about foil counterpoise systems in general, and the self-adhesive, thin foil > tape in specific. > > Thanks very much for your thoughts - all help is greatly appreciated as it > helps me avoid "reinventing the wheel". > > 73 KD2FT > Frank Fitz... and the crew of the mighty Draco > shssci@li.net Frank: It has been a few years since I installed radios on seagoing boats. Here a few suggestion on counterpoises which I have used in the past. If you are hand with fiber-glass resin you can do this. Procure some copper screen, the gauge or spacing is not important, if the bilge is still fairly clean, lay down the copper screen in the bilge and solder the edges where the screen overlaps. Cover as much of the bilge and up the sides of the hull as possible. This will be the ships countpoise. Copper foil in the bilge as works about as well. Ground all the ships machinery, including the negative side of the battery banks to this counter-poise. Only use a battery charger that has a low leakage transformer, no cheap auto ones. If you have a sailboat a back stay antenna will work fine. You will need a good antenna tuner if you use Ham gear as commercial transmitters usually have provisions for tuning seperate channels. You can use a running back-stay for you antenna also, just keep it as far from the other rigging as possible. Be sure to ground the stays to your ships ground. As you can see a good radio installation takes some doing. You have no idea the fun we had when fiber-glass boats came out. The next real challange will be to get all the noise out of the various equipment. Happy Sailing Cliff, W7VVA From lwbyppp@epix.net Thu Mar 21 13:40:19 1996 From: tiburch@halcyon.com (Terry Burch) Newsgroups: rec.radio.amateur.antenna Subject: AM antennas??? Date: Thu, 14 Mar 1996 05:58:10 GMT Message-ID: <4i8cbj$jo7@news.halcyon.com> Hi all, I tried posting this to the rec.audio.opinion group, but unlike most matters in that group :-), I have yet to get any opinions. Does anyone in this group have any advice? I have severe static-like interference on the low end of the AM band. I have tried the "long wire" AM antenna method and with an antenna 50 feet long the reception still has not improved . What I think I need is a selective AM antenna which will ignore some of the static I am picking up. I have been looking at the Terk AM FM Q and the Terk PI, as well as the Parsec Model 2000 AM/FM. Has anyone had any experience with these antennas? Have they made a difference in the reduction of AM static that you were getting? Terry tiburch@halcyon.com From lwbyppp@epix.net Thu Mar 21 13:40:20 1996 From: parf@aol.com (Parf) Newsgroups: rec.radio.amateur.antenna Subject: Re: Antenna Analyzers: AEA vs. MFJ Date: 15 Mar 1996 19:25:04 -0500 Message-ID: <4id1p0$mrp@newsbf02.news.aol.com> References: Reply-To: parf@aol.com (Parf) Hi Bill, Probably not many- of course my point was that the MFJ was "more accurate" than the AEA piece and considerably less expensive. In addition, V.S.W.R. or return loss is only a small fraction of what the hP will do. Then again, it's a bitch to haul up the tower! 73, Dale WA2YPY From lwbyppp@epix.net Thu Mar 21 13:40:21 1996 From: raiar@inlink.com (Gary V. Deutschmann, Sr.) Newsgroups: rec.radio.amateur.antenna Subject: Re: Antenna Analyzers: AEA vs. MFJ Date: Wed, 13 Mar 1996 22:48:41 GMT Message-ID: <4i7itu$g19@news1.inlink.com> References: <314485D7.4F4C@ldp.com> <4i35me$8lj@newsbf02.news.aol.com> <4i4gl6$eka@crash.microserve.net> I worked for some time at a well known antenna manufacturer, as well as designed several antennas myself. To date, I know of know device sold as an antenna analyzer that is functional or accurate throught the range claimed as it's parameters. I will give MFJ credit for manufacturing a low cost unit that performs better than some high priced models, although it is limited in usage. There are so many external factors that affect an antenna, that antenna tuning is an art best left to the end user and the associated problems of installation locations selected by the user, should not reflect on the manufacturers as to the viability of the claims they make concerning their antenna which can be assured, was tested under the most ideal of conditions. TTUL Gary From lwbyppp@epix.net Thu Mar 21 13:40:22 1996 From: Bill@halcyon.com Newsgroups: rec.radio.amateur.antenna Subject: Re: Antenna Analyzers: AEA vs. MFJ Date: Wed, 13 Mar 96 19:17:17 PDT Message-ID: References: <314485D7.4F4C@ldp.com> <4i35me$8lj@newsbf02.news.aol.com> In Article<4i35me$8lj@newsbf02.news.aol.com>, write: > I have owned them both -The AEA VHF/UHF and the MFJ HF-VHF w/ resistance > meter. I also own a brand new HP 8711B network analyzer that I used as a > benchmark. The AEA was quite optimistic in its readings and became more so > as the freq got higher. At 70cM it indicated 1:1 when the load was a > precision 75 Ohm termination. The MFJ was more accurate at VHF (it does > not do UHF). When I spoke to AEA about the accuracy I was told "that's > about what you should expect for a $400 instrument"- I sold it. > > Dale WA2YPY Dale, How many HP 8711Bs do you think HP would sell at $10,000 if the AEA and MFJ units were as accurate? Bill From lwbyppp@epix.net Thu Mar 21 13:40:23 1996 From: irwin@nai.net (Wayne Irwin) Newsgroups: rec.radio.amateur.antenna Subject: Re: Antenna Analyzers: AEA vs. MFJ Date: 13 Mar 1996 22:17:21 GMT Message-ID: <4i7hhh$h6u@a3bsrv.nai.net> References: <314485D7.4F4C@ldp.com> X-Newsreader: WinVN 0.92.6+ In article <314485D7.4F4C@ldp.com>, Rolfe Tessem says: > >Does anyone have any thoughts on the relative merits of these >two devices? The AEA appears to be better designed from an >ergonomic standpoint, while the MFJ seems to have more features >and beats AEA on price by a substantial margin. > >-- >Rolfe Tessem | Lucky Duck Productions, Inc. >rolfe@ldp.com | 96 Morton Street >(212) 463-0029 | New York, NY 10014 I dont have the AEA, but I did buy the MFJ a while back. Don't know I ever did without it. Tells you almost as much as a noise bridge, but its more convenient for an experimenter. Wayne, WA1RRZ From lwbyppp@epix.net Thu Mar 21 13:40:24 1996 Newsgroups: rec.radio.amateur.antenna From: n4lq@iglou.com (Steve Ellington) Subject: Re: Antenna for an IC-706 Message-ID: References: <4i98e7$8io@news.onramp.net> Date: Thu, 14 Mar 1996 15:00:09 GMT I've seen several questions lately about this. I too have an IC-706 but never considered trying to find an antenna to match the rig. I think the idea here is to find one antenna that does everything, like the rig. If this is the case, I don't think anyone makes an antenna that covers 160 through 6 meters. Even if they did, it would be a tremendous compromise on many bands and I don't recommend it. Otherwise, the Butternut with the 160mtr loading coil plus something else for 6 meters with a 2 position antenna switch may be your best choice of the multiband verticals. GAP antennas have a reputation of spotty performance. That is, they seem to work for some people and others have trashed them. Check the April Fool ad in this months new QST. The all band vertical that is only 17 inches tall! Also consider Icom's Auto tuner for the 706. I have heard some good reports on this little gadget. One guy I qsoed was using it in his car with an 8ft whip and could work all bands. : I am seeking information and opinions on an antenna to match with the ICOM 7 06. : I am considering the GAP Challenger DX vertical and the Butternut HF9VX (pl us : a separate 2 meter). Opinions and experieinces would be most appreciated. : tnx es 73, John : KC5RYQ -- Steve Ellington N4LQ@IGLOU.COM Louisville, Ky From lwbyppp@epix.net Thu Mar 21 13:40:25 1996 From: jcleland@onramp.net (John cleland) Newsgroups: rec.radio.amateur.antenna Subject: Antenna for an IC-706 Date: 14 Mar 1996 13:54:15 GMT Distribution: world Message-ID: <4i98e7$8io@news.onramp.net> Reply-To: jcleland@onramp.net I am seeking information and opinions on an antenna to match with the ICOM 706 . I am considering the GAP Challenger DX vertical and the Butternut HF9VX (plus a separate 2 meter). Opinions and experieinces would be most appreciated. tnx es 73, John KC5RYQ From lwbyppp@epix.net Thu Mar 21 13:40:25 1996 From: rupfold@white.lambton.on.ca (Rod Upfold) Newsgroups: rec.radio.amateur.antenna Subject: Antenna Help - don't be mad Date: 18 Mar 1996 08:55:01 -0500 Message-ID: <4ijpvl$mb8@white.lambton.on.ca> Please do not get mad..... I have looked for other antenna groups but could not find one..... My problem is with a television antenna. I have a combination head hooked up to an antenna pre-amp. My question is: can connect via a 300 ohm flat wire another uhf head to the combination head...and both go through the pre-amp.... I relly could use the help....local sellers do not know "dick" and I need help from an expert. Thank you Rod Upfold -- From lwbyppp@epix.net Thu Mar 21 13:40:30 1996 From: Rod Upfold Newsgroups: rec.radio.amateur.antenna Subject: Re: Antenna Help - don't be mad Date: Tue, 19 Mar 1996 10:14:51 -0500 Message-ID: References: <4ijpvl$mb8@white.lambton.on.ca> Sorry...the word that I think you concerned with...wasn't ment in a profane manner. I used it to mean that they could not answer any of my question. I apologize again.... Rod Upfold On Tue, 19 Mar 1996 armond@delphi.com wrote: > Rod Upfold writes: > > >I relly could use the help....local sellers do not know "dick" and I need > > This may come as a big suprise to you but profanity will sharply reduce > the offers to help you. > > From lwbyppp@epix.net Thu Mar 21 13:40:31 1996 Newsgroups: rec.radio.amateur.antenna From: n4lq@iglou.com (Steve Ellington) Subject: Re: Antenna Help - don't be mad Message-ID: References: <4ijpvl$mb8@white.lambton.on.ca> Date: Tue, 19 Mar 1996 20:48:48 GMT Ok. I'm an expert. Whats a UHF head???? What your are doing isn't quite clear. Sorry. Rod Upfold (rupfold@white.lambton.on.ca) wrote: : Please do not get mad..... : I have looked for other antenna groups but could not find one..... : My problem is with a television antenna. I have a combination head hooked : up to an antenna pre-amp. : My question is: can connect via a 300 ohm flat wire another uhf head to : the combination head...and both go through the pre-amp.... : I relly could use the help....local sellers do not know "dick" and I need : help from an expert. : Thank you : Rod Upfold : -- -- Steve Ellington N4LQ@IGLOU.COM Louisville, Ky From lwbyppp@epix.net Thu Mar 21 13:40:32 1996 From: aa0yt@mo.net (Colin Wright) Newsgroups: rec.radio.amateur.antenna Subject: Re: Antenna or Mast Amp - which is better ? Date: Sat, 16 Mar 1996 03:37:39 GMT Message-ID: <314a3727.1277720@news.mo.net> References: <4i2538$7di@nntp.ucs.ubc.ca> On 11 Mar 1996 21:14:16 GMT, djones@ucs.ubc.ca (David Jones) wrote: <...snip...> >Also, how can I find out what channels are available on UHF in my area ? Hi Dave. I keep a listing of AM/TV/FM stations on my web site. They are listed by grid field (CM, CN, etc.) and then subsorted by grid sqaure for the US and some of Canada and Mexico. The address is: http://walden.mo.net/~aa0yt Hope this helps! 73! Colin, AA0YT Colin R. Wright, AA0YT Certified OS/2 Engineer http://walden.mo.net/~aa0yt From lwbyppp@epix.net Thu Mar 21 13:40:33 1996 From: "Ian White, G3SEK" Newsgroups: rec.radio.amateur.antenna Subject: Re: Antenna or Mast Amp - which is better ? Date: Tue, 12 Mar 1996 17:12:24 +0000 Distribution: world Message-ID: References: <4i2538$7di@nntp.ucs.ubc.ca> In article , Joe Mack wrote among lots of good advice: > The coax is important too - it gets you twice - >if you have 3db of loss in the coax your signal goes >down 3db, but as well, the lossy coax adds noise >to the signal and it's about the same as the loss. That's hardly ever true, unless both the receiver noise and the noise picked up by the antenna are very low. >So your S/N goes down 6db. Usually it's little worse than 3dB, but that's important enough to make good coax worthwhile! Put in another way: if you have 3dB of loss in the coax, it's like you sawed your antenna in half (but please don't ask which half :-) 73 from Ian G3SEK Editor, 'The VHF/UHF DX Book' 'In Practice' columnist for RadCom (RSGB) Professionally: IFW Technical Services Clear technical English - anywhere. From lwbyppp@epix.net Thu Mar 21 13:40:34 1996 From: "Ian White, G3SEK" Newsgroups: rec.radio.amateur.antenna Subject: Re: Antenna or Mast Amp - which is better ? Date: Wed, 13 Mar 1996 07:09:09 +0000 Distribution: world Message-ID: <8KfT9CAVSnRxEwDk@ifwtech.demon.co.uk> References: <4i2538$7di@nntp.ucs.ubc.ca> In article <4i5173$gir@crash.microserve.net>, WB3U wrote: > mack@ncifcrf.gov "Joe Mack" wrote: > >>the lossy coax adds noise to the signal and it's about the same as >>the loss. > >Does this mean that I could roll up 500' of lossy coax, terminate >the unused end with a 50 ohm resistor, and use it as a wideband noise >generator? > Even though the original statement wasn't quite right, the answer is Yes. The coax will generate thermal noise equivalent to its physical temperature - but so too will the 50 ohm resistor. 73 from Ian G3SEK Editor, 'The VHF/UHF DX Book' 'In Practice' columnist for RadCom (RSGB) Professionally: IFW Technical Services Clear technical English - anywhere. From lwbyppp@epix.net Thu Mar 21 13:40:35 1996 Newsgroups: rec.radio.amateur.antenna From: mack@ncifcrf.gov (Joe Mack) Subject: Re: Antenna or Mast Amp - which is better ? Message-ID: References: <826647990snz@microvst.demon.co.uk> <4i5173$gir@crash.microserve.net> Date: Wed, 13 Mar 1996 17:02:02 GMT In article <4i5173$gir@crash.microserve.net> jackl@pinetree.microserve.com (WB 3U) writes: > mack@ncifcrf.gov "Joe Mack" wrote: > >>the lossy coax adds noise to the signal and it's about the same as >>the loss. > >Does this mean that I could roll up 500' of lossy coax, terminate >the unused end with a 50 ohm resistor, and use it as a wideband noise >generator? > >73, >Jack WB3U This was all a surprise to me when I realised that lossy coax also generated noise, but from what I know, what you're proposing will do exactly that. It will be a perfect noise generator at approx 300degK. Most noise diodes have an equivelent noise temp of several 1000 def K. 73 de Joe NA3T mack@ncifcrf.gov X From lwbyppp@epix.net Thu Mar 21 13:40:35 1996 From: Brunob@glo.be (Bruno Beckers) Newsgroups: rec.radio.amateur.antenna Subject: Re: Antenna or Mast Amp - which is better ? Date: Wed, 13 Mar 1996 22:42:51 GMT Message-ID: <4i7j99$pb7@rhea.glo.be> References: <4i5173$gir@crash.microserve.net> In my opinion, a mast amp is better, because when you ampify the mast, it gets bigger and higher wich results in a lower radiation angle for you antenna. On the other hand, if you amplify your antenna, it will be hopelessly out of tune... :-) Bruno Beckers Brunob@glo.be From lwbyppp@epix.net Thu Mar 21 13:40:36 1996 From: parf@aol.com (Parf) Newsgroups: rec.radio.amateur.antenna Subject: Re: Antenna or Mast Amp - which is better ? Date: 13 Mar 1996 17:43:58 -0500 Message-ID: <4i7j3e$or2@newsbf02.news.aol.com> References: <01BB1063.D8524E60@dns.netis.com.198.186.186.2> Reply-To: parf@aol.com (Parf) Hi Dave, The mast mounted preamp (assuming a decent noise figure such as the Winegard low noise pieces) would at the very least establish the noise floor for your system. Without it the noise figure would be the noise figure of the front end of the TV receiver ( typically 5 dB VHF and maybe as much as 8dB UHF)+ the loss in the coax. Forget about the "focusing effect" of a larger antenna. Antennas for VHF and or VHF/UHF do not have clean side lobes and will always p/u man made noise despite their gain. Go with the preamp. Winegard used to make balanced input preamps. These were great because they didn't need a balun and its attendant 3-4 dB loss at UHF and probably a dB or 2 at VHF. They are no longer available new but can be found at MATV shops occasionally. 73, Dale WA2YPY From lwbyppp@epix.net Thu Mar 21 13:40:37 1996 From: jgkamm@mis.net Newsgroups: rec.radio.amateur.antenna Subject: Any experience with Loop Antennas? Date: 14 Mar 1996 01:01:29 GMT Message-ID: <4i7r59$okd@netnews.mis.net> I need to get a low profile 20 meter antenna and am looking at the IsoLoop from AEA, MFJ has one also. does anyone have any experience with these? +/- experience? JOHN KF4GBV From lwbyppp@epix.net Thu Mar 21 13:40:38 1996 From: BFLETCHE@MAIL.STATE.WI.US Newsgroups: rec.radio.amateur.antenna Subject: BCB antenna Date: 13 Mar 96 15:34:03 GMT Message-ID: <0003800003174410000004*@MHS> I need help locating companies that make BCB outdoor loop antennas with preamp. Thanks. Bill Fletcher AF9B bfletche@mail.state.wi.us From lwbyppp@epix.net Thu Mar 21 13:40:39 1996 From: davidc@scoot.NETis.COM (David, Michaela & Benjamin) Newsgroups: rec.radio.amateur.antenna Subject: Best No Gnd Radial HF Vertical Date: 16 Mar 96 19:07:09 GMT Message-ID: <01BB134D.C7A1CD60@dns.netis.com.198.186.186.2> Help! I have chosen to scale my station way back as it won't get much use for the next 2 years. I want to put up an HF vertical that works reasonably well without ground radi als or guy wires. 80-10 including WARC is a pipe dream, 40-10 including WARC nice (esp. if full band coverage), 20-10 including WARC (must be full band coverage) ok. The Cushcraft R-5 appears to meet the latter requirement, the R-7 trims 20, 30 & 40. I don't know about the GAP Titan, the Butternut HF9V-X, or the new Cushcraft R-7000. Am I missing any antennas that belong on this list? Thanks in advance for any guidance here. No point in putting up something that won't cut it, but want something simple and clean for now. 73, David AA1FA From lwbyppp@epix.net Thu Mar 21 13:40:40 1996 From: fervor@clark.net (Exiled on Main Street) Newsgroups: rec.radio.amateur.antenna Subject: Beveridge antennas Date: 14 Mar 1996 20:19:05 GMT Message-ID: <4i9uvp$j2v@clarknet.clark.net> Hello all... I need to find out more about the construction of a beveridge antenna. Anyone know where i can get some instructions on constructing a balun for one? Please respond via email. Thanx! -Tim From lwbyppp@epix.net Thu Mar 21 13:40:41 1996 From: vfiscus@mcn.net (Vince Fiscus, KB7ADL) Newsgroups: rec.radio.amateur.antenna Subject: Re: BUTTERNUT HF9V & Counterpoise - Advice Pse Date: Thu, 21 Mar 96 01:06:53 GMT Message-ID: <4iqa5g$ofa@news.mcn.net> References: <4im5di$a8d$1@sydney.DIALix.oz.au> Keywords: Antenna Vertical I ground-mounted my vertical and buried the radials, works great. 73 de KB7ADL In article <4im5di$a8d$1@sydney.DIALix.oz.au>, rhg@sydney.DIALix.oz.au (Robin Gandevia) wrote: > RE: BUTTERNUT HF9V and BUTTERNUT COUNTERPOISE > > I am in a dilemma and would appreciate your opinion as to the > merits of the Butternut counterpoise kit compared to radials. > > I would like to buy the Butternut HF9V - the all HF band > vertical antenna. I currently have an R5 for 20 through 10, and > a base loaded home-brew ground plane for 80, 40 and 30 metres. > > I must "clear up the mess". The new antenna would have to be > mounted on the side of the house - up to 10 feet above the roof. > Radials for 8 HF bands are impractical. I have a tin roof but > unfortunately it has "color-bonding" together with silicone > between sheets. Conductivity between sheets is minimal. The > other problem is the shape of the roof. The house is typical > "terrace" design - an "A" frame at the front with a long > scillion rear roof. The mounting point is midway in the rear > section. My poor drawing skills... > > | > | > | . > | / \ > | / \ > ______________________ / \ > | | E------W > | | > rear | side | front > | | > |__________________________________| > < c. 50' > > > The obvious answer seems the Butternut counterpoise. But is it? > I am reticent to use the roof as a counterpoise for a few > reasons... > > - Poor connections between sheets may cause TVI with the diode > effect. > > - If the antenna base is mounted at the roof level, the "A" > frame section 20 feet away will be higher than it. > > - The antenna will be mounted at the SIDE of the roof - thus > only a 50% coverage of roof below. > > I would be interested in your opinion. I'd be especially > grateful to hear from anyone who has any experience with the > Butternut counterpoise. I haven't seen one, nor do I know anyone > who even has the Butternut antenna, though I understand it is > very good. To be honest, I've not been happy with the R5. But if > the Butternut and its counterpoise will not be as good then I > might see if I can persuade the powers to be to let it stay! > > It is kind of you to read me request for assistance - thank you. > > Robin Gandevia VK2VN > > > From lwbyppp@epix.net Thu Mar 21 13:40:42 1996 From: dbwillia@uci.edu (Brian Williams) Newsgroups: rec.radio.amateur.antenna Subject: Re: Car AM Antennas to 2 Meter Date: 17 Mar 1996 15:25:13 GMT Message-ID: <4ihasp$r3v@news.service.uci.edu> References: <4ibpqg$1jq@ns.oar.net> In article <4ibpqg$1jq@ns.oar.net>, jaeschke@cordmc.dnet.etn.com says... >Last December WA6ILQ posted a reply to a question about >disguise antennas. He said that the "big name" in these >antennas was/is STICO. I have tried to find the phone number >of this firm and have not been able to locate them. I don't have STICO's phone number, but I know that Antenna Specialists makes disguise antennas and couplers for disguise antennas. I use a Hustler 2meter antenna on my '67 Mustang in the normal antenna location (a cowl mount) and the coupler allows reception on FM real well (AM reception is not good). The location (fender) isn't the best location, but it really don't look like a transmitting antenna to most people. Brian From lwbyppp@epix.net Thu Mar 21 13:40:43 1996 From: rval58@aol.com (Rval58) Newsgroups: rec.radio.amateur.antenna Subject: Carolina Windom 80 Question Date: 20 Mar 1996 14:40:33 -0500 Message-ID: <4ipmvh$slg@newsbf02.news.aol.com> Reply-To: rval58@aol.com (Rval58) I've heard some good things about the Carolina Windom 80 from Radio Works. Haven't seen much in this group about the antenna. Anyone have one? I was wondering in addition to it's performance, what kind of SWR and RFI can be expected? Using a G5RV now. - Thanks. From lwbyppp@epix.net Thu Mar 21 13:40:45 1996 Newsgroups: rec.radio.amateur.antenna From: gary@ke4zv.atl.ga.us (Gary Coffman) Subject: Re: Comet GP9-N vs Diamond X500HNA Message-ID: <1996Mar17.173850.11632@ke4zv.atl.ga.us> Reply-To: gary@ke4zv.atl.ga.us (Gary Coffman) References: <313D20CB.7FAF@intermediainc.com> <313D33A4.46B3@intermediainc.com> Date: Sun, 17 Mar 1996 17:38:50 GMT In article <313D33A4.46B3@intermediainc.com> Jeff DePolo WN3A writes: >Has anyone had the chance to compare these two antennas? At one of my >repeater sites, I'm going to be replacing VHF and UHF monoband antennas >with a single dual-band antenna, and am trying to decide which. I have >a Diamond X500HNA that I used for a while on the 2m and 440 remote bases >tied to a repeater, and, although it was OK, it's performance on UHF >didn't compare favorably to single-band UHF antennas that I've A/B >compared it to at the same site (Celwave PD-455, Diamond F718A, etc.), >so I'm wondering if the Comet GP9-N is a better alternative. Other than I think that the Comet antennas use a better electrical construction than the Diamond, I'm not sure there are any major performance differences, IE the Comets tolerate lightning strikes better than the Diamonds due to the fact there are no series capacitors to rupture in the element stack. Phasing is done by "linear loading". But I have noticed something else. The UHF vertical pattern profiles of either of these dual banders is not as desirable as the vertical profile of a single band antenna. These antennas are optimized for proper phasing at 2m, not at the high end of 70cm. 3x146=438, and these antennas have good patterns at 438 MHz, but not at 448 MHz. We'd like a bit of electrical downtilt for a repeater antenna, but the dualbanders give us a bit of electrical uptilt instead. That's fine for working aircraft, or warming birds, but it's not much use to us as a high site repeater antenna. Gary -- Gary Coffman KE4ZV | You make it, | Due to provider problems Destructive Testing Systems | we break it. | with previous uucp address es 534 Shannon Way | Guaranteed! | Email to ke4zv@radio.org Lawrenceville, GA 30244 | | From lwbyppp@epix.net Thu Mar 21 13:40:46 1996 From: aa6eg@tmx.COM (Pat Barthelow) Newsgroups: rec.radio.amateur.antenna Subject: Discone Radiation Patterns Date: 13 Mar 96 15:37:34 GMT Message-ID: A design article on discones exists in the June 1955 Electronics Buyers Guide, by J.J. Nail. Reference Sheet, R-27. This article references 3 other articles in the literature, which are: A.G Kandolan, "Three New Antenna Types and their Applications Proc IRE, 34, p. 70 W Feb. 1946 A.G. Kandolan, W. Sichak, R.A. Felsenheld, "Elecronic Communication", 25, P. 139, June 1948 J.M. Bower, "Discone - 40 to 500 Mc. Skywire", CQ, 5, p. 11, July 1950 Mack Seybold, "The Low frequency Discone", CQ 6, p. 13, July 1950 To summarize the Nail article, Impedance plots show that for Flare angles (the complete inside angle of the cone) between 25 and 60 degrees, SWRs to a 50 ohm feed, of 1.5 to 2 to one, exist until the lower frequency limit is reached, then a rather steep climb in SWR occurs. The lower frequency limit is defined by the length of the sloping side of cone becoming a 1/4 wavelength. Slight variations in impedance occur up through 3F, but are inconsequential. At the upper frequency limits, (5 or more F) patterns and impedance are mostly influenced by the dimensions at the pointy end of the cone, and to a degree, by the flare angle. It appears that best performance occurrs when the cone vertex is as pointy as possible and spaced as close as possible to the center of the disk. Free space pattern plots in the vertcal plane at the lower frequencies look like a vertical dipole. As the frequency gets higher, the dipole pattern gets squeezed at the bottom quarter, so that it looks like a pair of commas, back to back, at 3F. The gain at the horizon is -3.3 dbd at 3.75F, and - 2.5 dbd at 4.85 F. Someone should use Lewallen's modelling program to verify these early computed plots. I would like to know if you can minimize the numbers of wires you model, to the point of using only a 2 dimensional model, requiring fewer segments of wire, and assumptions being made that the pattern is the same omnidirectionally. Bottom line is, consider the discone to be about like a 1/4 wave ground plane with an upper F limit of up to 10 times F min. i.e. a discone with a cone length of 20 inches should perform well, from 2 meters to well above 1.2 gHz, if the junction area is constructed properly. BTW, if you are ever in Monterey, contact me, for a looksee at our 80-10 METER discone, courtesy of the US Army, at our new club station, the former Army MARS station at Ft. Ord. Works DX like gangbusters from 80 through 10 meters. 73, DX, de Pat, aa6eg@tmx.com Monterey CA From lwbyppp@epix.net Thu Mar 21 13:40:47 1996 From: "Ian White, G3SEK" Newsgroups: rec.radio.amateur.antenna Subject: Re: European 4 to 5 wavelength boom 144 MHz Yagis? Date: Sat, 16 Mar 1996 08:29:12 +0000 Distribution: world Message-ID: <4Efc5GAYvnSxEw73@ifwtech.demon.co.uk> References: <3149089A.1771@nmp.nokia.com> Ilkka Kontola wrote: >Is there European manufacturers for four to five wavelength >boom 144 MHz Yagi antennas? Yes, Eagle Antennas in the UK manufacture antennas under license from DJ9BV, similar to the designs published in DUBUS. Contact Vine Antennas (GW3YDX) on +44 1691 831111, fax +44 1691 831386 or by mail at: Vine Antenna Products The Vine Llandrinio Powys SY22 6SH United Kingdom (Yes, Llandrinio does begin with two Ls, same as the Lewallen family name used to!) >If any is there any references concerning their usability >in four or six yagi EME arrays? > Plenty of good experience worldwide! 73 from Ian G3SEK Editor, 'The VHF/UHF DX Book' 'In Practice' columnist for RadCom (RSGB) Professionally: IFW Technical Services Clear technical English - anywhere. From lwbyppp@epix.net Thu Mar 21 13:40:49 1996 From: mcewenjv@songs.sce.COM (MCEWEN, JAMES) Newsgroups: rec.radio.amateur.antenna Subject: Feeding a helical wound antenna Date: 13 Mar 96 17:57:44 GMT Message-ID: <9602138267.AA826739998@ccgate.songs.sce.com> Resend of msg 3/8/96 Hello to the list. Like a lot of others, I have a severe space problem and want to get by with one reasonable antenna. I am considering an 80 meter helical wound antenna across the ceiling of the shack. The Handbook sez use 1 wavelength of wire, largest size practical, spacing of the turns isn't important to performance. So OK. Now here is the problem. How do I feed the thing to get all band (or most band) performance? The handbook sez this will have a low feedpoint impedance. It suggests using a few turns of wire as a primary transformer winding (link Coupling), with a variable cap in series to resonate the coil, into 50 ohm coax. But this is for only 1 band. How do I connect broadband? A MFJ949D is available for matching and a dip meter for tuning. One idea was to make a short length of open wire, like this: ___________----------- _______----------- 450 ohm openwire antenna ~20 ohm spacing to spacing to input at end -------___________ MFJ 949D "coil link" -----------___________ or another idea: Use a tapped coil link to make impedance transformations, at the antenna: / \ / ant \ link / coil (10-20 turns?) 80 \ \- / /_ ____________________ meter\ \_ / / To Openwire input 200 \ \_Taps MFJ 949D turns/ /_ -------------------- \ \- / \ Comments & suggestions, please TIA Jim McEwen KA6TPR starsekr@cnsii.com From lwbyppp@epix.net Thu Mar 21 13:40:50 1996 From: Cecil Moore Newsgroups: rec.radio.amateur.antenna Subject: fiberglas rods/pipe Date: 13 Mar 1996 19:21:04 GMT Distribution: world Message-ID: <4i7770$jvk@chnews.ch.intel.com> I've been asked where to get some. Got mine at Ryan Herco in Tempe, AZ. They also have 6 offices in N/S CA, Albuquerque, Portland, Seattle, Austin, and Houston. 73, Cecil, KG7BK, OOTC (not speaking for my employer) From lwbyppp@epix.net Thu Mar 21 13:40:51 1996 From: thompson@atl.mindspring.com (David L. Thompson) Newsgroups: rec.radio.amateur.antenna Subject: Re: Force 12 info request Date: Mon, 18 Mar 1996 02:35:35 GMT Message-ID: <4iihmi$3cc@firebrick.mindspring.com> References: <5MAR199612334184@ubvms.cc.buffalo.edu> Reply-To: thompson@atl.mindspring.com oopdavid@ubvms.cc.buffalo.edu (D.RODMAN) wrote: >Can anyone give me a number or address for Force 12 antennas? I am >looking for specific information on 20 m monobanders. Thanks, Dave. Force 12 has ads in virtually all ham mags. Dave K4JRB From lwbyppp@epix.net Thu Mar 21 13:40:52 1996 From: kkoelman@ix.netcom.com(Koert Koelman ) Newsgroups: rec.radio.amateur.antenna Subject: Free Tower/Antenna Mountain View CA Date: 16 Mar 1996 06:00:12 GMT Message-ID: <4idldc$o1k@ixnews2.ix.netcom.com> A friend of mine just bought a house in Mountain View, CA and the previous owner left a tower/antenna behind. It is yours free for the asking, if you take the tower down, take both the antenna and the tower and haul it yourself. * 40-feet crank-up Tristao tower * Tri-bander yagi * Possibly also a 2-meter antenna (I am not sure about this) If you are interested, act fast as he wants to clear up his yard. Call Tim at 415-960-0430 or send him an e-mail at ttpole@dbc.com. 73/Koert KC6WCI From lwbyppp@epix.net Thu Mar 21 13:40:54 1996 From: w8jitom@aol.com (W8JI Tom) Newsgroups: rec.radio.amateur.antenna Subject: Re: G5RV coax length Date: 15 Mar 1996 15:54:21 -0500 Message-ID: <4icldt$i20@newsbf02.news.aol.com> References: <4i7itu$g19@news1.inlink.com> In article , n4lq@iglou.com (Steve Ellington) writes: >I also found that if you wad the coax up and let it lay on the >ground the swr appears even lower. If that happens, the feedline has common mode currents, either from lack of a choke balun or improper feedline routing. >All of this goes to show the how the G5RV was never intended to be a multiband >antenna in the first place when fed with coax. Only 20 meters was originally >considered. MR G5RV himself recommends using open wire feeders when used as a >multiband antenna. Something very nice occurs, intentionally or not. On 80 meters the 30 ft high Z line adds inductive reactance that cancels capacitive reactance caused by the antenna being too short. On 40 meters, the 30 ft high Z line acts like 1/4 wl transmission line transformer, and reduces the very high center impedance to a reasonable value. On 20 meters, the 30 ft high Z line repeats the impedance at the antenna, which is low. My G5RV has a resonable SWR on 80, 40, and 20. It's also easy to match with a tuner. Very few randomly constructed open wire fed antennas are easy to match on all bands, even though they use a tuner. Disadvantages attributed to G5RV's are more rumor than fact. >A lossy coax can turn a 5:1 swr into an nice 1.2:1 if it is long enough. Well, just how long is long enough??? To reduce VSWR from 5:1 to 1.2:1 requires 8.65 dB of cable loss. A typical RG-58 cable I looked up would be around 300 feet long on ten meters, or over 500 feet long on 40 meters to provide that much loss. RG-8X would have to be much longer. >Further, when a line has a mismatch like yours, the swr will appear to >vary for different lengths of line on any given frequency. Not so at all !!! SWR remains constant except for the reduction of SWR caused by attenuation unless: 1.) The feedline is improperly installed. 2.) The bridge or line have different design impedances. >Sometimes a decent compromise can be achieved by experimenting with various >short sections of coax added to your feeder. This is real easy on the higher >bands where just a short 3ft jumper from the tuner to the rig can make a >huge different in swr READINGS. If changing the length of the 50 ohm line changes the SWR measured by a 50 ohm VSWR meter, one of the above rules is being broken. Either repair the meter, buy a real 50 ohm line, re-route the feedline as it leaves the antenna, or de-couple the feedline with a choke balun. Something is very wrong, OTHER than line matching or SWR". 73 Tom From lwbyppp@epix.net Thu Mar 21 13:40:54 1996 From: gpt@qni.com (George P. Thomas, Jr.) Newsgroups: rec.radio.amateur.antenna Subject: GAMMA-MATCH FOR 2M YAGI Date: Sun, 17 Mar 1996 16:38:27 GMT Message-ID: <4ih96m$665@suba01.suba.com> Does anyone have or know where I can find DETAILS regarding building a gamma-match for a 3 element 2m yagi? Thank You and 73's...KB0QVT From lwbyppp@epix.net Thu Mar 21 13:40:56 1996 From: moritz@ipers1.e-technik.uni-stuttgart.de () Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.equipment Subject: Re: GAP Voyager DX vertical antenna. Date: 15 Mar 1996 08:55:22 GMT Message-ID: <4ibb9q$1k38@info4.rus.uni-stuttgart.de> References: <4i2h8i$r80@news.mcn.net> In article <4i2h8i$r80@news.mcn.net>, Vince Fiscus, KB7ADL wrote: > >Is the GAP Voyager DX a good vertical ? Well, it depends what you call a good vertical. it is quite expensive and looks impressive, However, performance is similar to a dummy load. It is easily beat by a dipole at the same height. A good vertical comes with a ground plane. 73, Moritz DL5UH From lwbyppp@epix.net Thu Mar 21 13:40:56 1996 From: jayw@pnn.com (Jay Whitworth) Newsgroups: rec.radio.amateur.antenna Subject: Re: Glass mount dualband antenna Date: Wed, 13 Mar 96 02:32:22 GMT Message-ID: <4i5c3m$buk_002@t1.pnn.com> References: <4htn6p$oqr@newsbf02.news.aol.com> In article <4htn6p$oqr@newsbf02.news.aol.com>, frankb2686@aol.com (FrankB2686) wrote: >Anyone have experience (good or bad) using a glass mount 2m/70cm antenna? >Comments on installation, manufactures, etc. would be appriciated. > >73 Frank WD6AGS > I have been using a Larson dual band Kulglass antenna for about a year. It wor ks resonably well. I have been told that glass mount antennas don't work with some dark tinted wi ndows. Be careful in positioning the antenna base on the outside of the window, becau se once it makes contact with the glass it is STUCK! 73, Jay Whitworth, WB7NNA From lwbyppp@epix.net Thu Mar 21 13:40:57 1996 From: parf@aol.com (Parf) Newsgroups: rec.radio.amateur.antenna Subject: Re: Glass mount dualband antenna Date: 15 Mar 1996 19:16:16 -0500 Message-ID: <4id18g$mkh@newsbf02.news.aol.com> References: <4i5c3m$buk_002@t1.pnn.com> Reply-To: parf@aol.com (Parf) Hi Frank, Iwas the original designer and patent holder of the on-glass series (now owned by Antenna Specialists). Our design was an end fed 1/2 wave whic worked well because it did not want to seek a counterpoise. The coax was cold enough that V.S.W.R. did not vary at all as cable was routed or moved. Haven't inspected the Larsens's for years but they used to be a curren fed design w/ a minimal exterior counterpoise and fed by 2 capacity plates at the 50 Ohm level thru the glass. The feedline was reasonably hot w/ RF. The window tints are death to any of the on glass- probably more so to my design because of the relatively hi end Z- 500 Ohms or so @2M. You need to "open an area w/ a 1/2" boarder around the foot. The A.S. antennas showed slight gain over roof mounted quarter waves when the antenna was mounted near the top of the window. The pattern was quite omni and the gain may have resulted from the fact that the current loop was almost a quarter wave higher up than the roof mounted monopole. 73, Dale WA2YPY From lwbyppp@epix.net Thu Mar 21 13:40:59 1996 From: tom_boza@ccm.ch.intel.com (WB7ASR) Newsgroups: rec.radio.amateur.antenna Subject: Re: Glass mount dualband antenna Date: 14 Mar 1996 15:31:09 GMT Distribution: world Message-ID: <4i9e3t$mbe@chnews.ch.intel.com> References: <4htn6p$oqr@newsbf02.news.aol.com> zdanowsk@cybernex.net wrote: >frankb2686@aol.com (FrankB2686) wrote: > >>Anyone have experience (good or bad) using a glass mount 2m/70cm antenna? >>Comments on installation, manufactures, etc. would be appriciated. > >>73 Frank WD6AGS > >Does anyone have any experience using the glass mount, is the and >difference to rx or tx as opposed to drilling a hole into my brand new >car. Im using the Vertex 99 channel uhf model. >Any make or model? > I have the Larson dual-band glass mount antenna. When I first installed it, the SWR was high on the high end of two meters band and HIGH across the intire 70cm band. I called Larson on the telephone and they sent me a new whip, which is longer above the center loading coil. This fixed my SWR problem on both bands. Its should be noted, the reason why the other shorter whip had a higher SWR, was because of the metal film window tinting. Window tinting causes the capatance to change between the two glass mount sections, thus shorting the electrical length of the whip. Hope this info helps, Tom... From lwbyppp@epix.net Thu Mar 21 13:40:59 1996 From: Cliff Soderback Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew Subject: Re: ground a 5/8 wave on a trunk lip mount? Date: Thu, 14 Mar 1996 18:43:41 -0800 Message-ID: <3148D95D.389F@cris.com> References: To: Charlie Fortner Charlie Fortner wrote: > > I've got a trunk lip mount and I want to use a 5/8 wave antenna with it. > If I attach a piece of wire running from the ground of the antenna to a > suitable ground in the trunk, will this have the same affect as putting > the antenna on the roof of my car? Thanks. > > Charlie Fortner > KF4GJQ Charlie: The wire wouldn't do anything because the 5/8 ant in grounded in the mount. If you have a fiberglass car then only a 1/2 wave would work, because you have no ground. Note: a 1/4 wave on top of the car will work better than any antenna mounted on the trunk. Cliff, W7VVA From lwbyppp@epix.net Thu Mar 21 13:41:01 1996 From: Jim Devenport Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew Subject: Re: ground a 5/8 wave on a trunk lip mount? Date: Thu, 14 Mar 1996 13:40:32 -0700 Message-ID: <31488440.5629@lanl.gov> References: To: Charlie Fortner Hardly. Your ground normally takes place through the screws that you tighten under the trunk mount to hold it in place, they are supposed to pierce the paint and make a ground connection. For your ground wire to have any useful effect it would have to be a more direct connection than that to ground. Plus, mounting the antenna in or on the vehicle roof not only gives it the benefit of the surrounding roof surface as a ground plane but elevates it another foot or more, plus the pattern will be more omnidirectional since there should be no other metal obstructions in the near field of the antenna. In actual operation it may often be difficult to notice any improvement from trunk to roof mounting. -- |-------------------------------------------------------| |Jim Devenport WB5AOX | |All Standard Disclaimers Disclaimed | |My views rarely (if ever) reflect those of my employers| |HTTP://nis-www.lanl.gov/~jdport/ | |-------------------------------------------------------| From lwbyppp@epix.net Thu Mar 21 13:41:02 1996 Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew From: gary@ke4zv.atl.ga.us (Gary Coffman) Subject: Re: ground a 5/8 wave on a trunk lip mount? Message-ID: <1996Mar15.023820.29750@ke4zv.atl.ga.us> Reply-To: gary@ke4zv.atl.ga.us (Gary Coffman) References: Date: Fri, 15 Mar 1996 02:38:20 GMT In article charlie@netdepot.co m (Charlie Fortner) writes: >I've got a trunk lip mount and I want to use a 5/8 wave antenna with it. >If I attach a piece of wire running from the ground of the antenna to a >suitable ground in the trunk, will this have the same affect as putting >the antenna on the roof of my car? Thanks. No. For the current mirror to be effective, it has to be directly under the antenna. The only way to get top of the car performance is to mount the antenna on the top of the car. Mounting on the trunk will result in directional properties because the signal will be shielded by the cabin to the front, and because the groundplane under the antenna will be asymmetric. Running a wire inside the car will have no effect on the antenna pattern. The antenna is already "grounded" by the trunk lip mount. THe trunk lid is its groundplane (such as it is). Gary -- Gary Coffman KE4ZV | You make it, | Due to provider problems Destructive Testing Systems | we break it. | with previous uucp address es 534 Shannon Way | Guaranteed! | Email to ke4zv@radio.org Lawrenceville, GA 30244 | | From lwbyppp@epix.net Thu Mar 21 13:41:06 1996 From: jmaynard@admin5.hsc.uth.tmc.edu (Jay Maynard, K5ZC) Newsgroups: rec.radio.amateur.misc,rec.radio.amateur.antenna,rec.radio.amateur.digital.misc,rec.radio.amateur.equipment,rec.radio.amateur.homebrew,rec.radio.amateur.policy,rec.radio.amateur.space,rec.radio.cb,rec.radio.info,rec.answers,news.answers Subject: Guide to the Personal Radio Newsgroups Date: 16 Mar 1996 07:05:20 GMT Distribution: world Message-ID: Reply-To: jmaynard@admin5.hsc.uth.tmc.edu (Jay Maynard, K5ZC) Summary: This article provides an overview of the newsgroups devoted Keywords: faq radio amateur ham cb netiquette Posted-By: auto-faq 3.1.1.2 Archive-name: radio/personal-intro Revision: 2.1 1994/11/01 03:50:23 Posting-Frequency: posted on the 15th of each month This message describes the rec.radio.amateur.*, rec.radio.cb, rec.radio.info, and rec.radio.swap newsgroups, as well as their Internet mailing list counterparts and complements. It is intended to serve as a guide for the new reader on what to find where. Questions and comments may be directed to the author, Jay Maynard, K5ZC, by Internet electronic mail at jmaynard@admin5.hsc.uth.tmc.edu. This message was last changed on 31 October 1994 to add the discussion of non-Usenet mailing lists and streamline most of the history discussion, and to change the moderator information for rec.radio.info. History ======= Way back when, before there was a Usenet, the Internet hosted a mailing list for hams, called (appropriately enough) INFO-HAMS. Ham radio discussions were held on the mailing list, and sent to the mailboxes of those who had signed up for it. When the Usenet software was created, and net news as we now know it was developed, a newsgroup was created for hams: net.ham-radio. The mailing list and the newsgroup were gatewayed together, eventually. Over the years, as the net grew, the volume of discussion became progressively higher. First one by one, and then as part of two reorganizations, what was once one group became many. In the process, developments elsewhere on the net were reflected in the groups as they were created, most notably the change to place all of the ham radio groups in one hierarchy. The collection of newsgroups continues to grow as more people join the net, and as more topics of discussion gain volume, I expect to see more groups be created as well. This follows what is happening on the rest of the net. Nearly all of the radio newsgroups have corresponding mailing lists, the notable exception being rec.radio.swap. There are also a few mailing lists that don't have newsgroups. The Current Groups ================== It's important to post messages to the group that's appropriate for them, and not to the groups that aren't. The whole idea of having different newsgroups is so that folks who aren't interested in, say, homebrewing, don't have to wade through messages about homebrewing on the way to read about Field Day. Posting appropriately is just good etiquette. The rec.radio.amateur.misc group is the catchall. It is what rec.ham-radio was renamed to during the first major reorganization. Any message that's not more appropriate in one of the other groups belongs here, from contesting to DX to ragchewing on VHF to information on becoming a ham. The group rec.radio.amateur.digital.misc is for discussions related to (surprise!) digital amateur radio. This doesn't have to be the common two-meter AX.25 variety of packet radio, either; some of the most knowledgeable folks in radio digital communications can be found here, and anything in the general area is welcome. The name was changed to emphasize this, and to encourage discussion not only of other text-based digital modes, such as AMTOR, RTTY, and Clover, but things like digital voice and video as well. The former group, rec.radio.amateur.packet, was removed on September 21st, 1993. It is obsolete, and you should use .digital.misc instead (or the appropriate new mailing list, mentioned below). The group has .misc as part of the name to allow further specialization if the users wish it, such as .digital.tcp-ip. The swap group is rec.radio.swap. This recognizes a fact that became evident shortly after the original group was formed: Hams don't just swap ham radio gear, and other folks besides hams swap ham equipment. If you have radio equipment, or test gear, or computer stuff that hams would be interested in, here's the place. Equipment wanted postings belong here too. Discussions about the equipment generally don't; if you wish to discuss a particular posting with the buyer, email is a much better way to do it, and the other groups, especially .equipment and .homebrew, are the place for public discussions. There is now a regular posting with information on how to go about buying and selling items in rec.radio.swap; please refer to it before you post there. To answer a frequently asked question: No, there is no mailing list that goes along with this group. If you can't read Usenet news directly, you're out of luck. The group rec.radio.amateur.policy was created as a place for all the discussions that seem to drag on interminably about the many rules, regulations, legalities, and policies that surround amateur radio, both existing and proposed. Recent changes to the Amateur Radio Rules (FCC Part 97) have finally laid to rest the Great Usenet Pizza Autopatch Debate - it's now legal to order a pizza on the autopatch, if you're not in the pizza business - as well as complaints about now-preempted local scanner laws hostile to amateurs, but plenty of discussion about what a bunch of rotten no-goodniks the local frequency coordinating body is, as well as the neverending no-code debate, may still be found here. The group rec.radio.cb is the place for all discussion about the Citizens' Band radio service. Such discussions have been very inflammatory in rec.ham-radio in the past; please do not cross-post to both rec.radio.cb and rec.radio.amateur.* unless the topic is genuinely of interest to both hams and CBers - and very few topics are. The rec.radio.info group is just what its name implies: it's the place where informational messages from across rec.radio.* may be found, regardless of where else they're posted. As of this writing, information posted to the group includes Cary Oler's daily solar progagation bulletins, ARRL bulletins, the Frequently Asked Questions files for the various groups, and radio modification instructions. This group is moderated, so you cannot post to it directly; if you try, even if your message is crossposted to one of the other groups, your message will be mailed to the moderator, who is currently David Dodell, WB7TPY. The email address for submissions to the group is rec-radio-info@stat.com. Inquires and other administrivia should be directed to rec-radio-info-request@stat.com. For more information about rec.radio.info, consult the introduction and posting guidelines that are regularly posted to that newsgroup. The groups rec.radio.amateur.antenna, .equipment, .homebrew, and .space are for more specialized areas of ham radio: discussions about antennas, commercially-made equipment, homebrewing, and amateur radio space operations. The .equipment group is not the place for buying or selling equipment; that's what rec.radio.swap is for. Similarly, the .space group is specifically about amateur radio in space, such as the OSCAR program and SAREX, the Shuttle Amateur Radio EXperiment; other groups cover other aspects of satellites and space. Homebrewing isn't about making your own alcoholic beverages at home (that's rec.crafts.brewing), but rather construction of radio and electronic equipment by the amateur experimenter. Except for rec.radio.swap and rec.radio.cb, all of these newsgroups are available by Internet electronic mail in digest format; send a mail message containing "help" on a line by itself to listserv@ucsd.edu for instructions on how to use the mail server. All of the groups can be posted to by electronic mail, though, by using a gateway at the University of Texas at Austin. To post a message this way, change the name of the group you wish to post to by replacing all of the '.'s with '-'s - for example, rec.radio.swap becomes rec-radio-swap - and send to that name@cs.utexas.edu (rec-radio-swap@cs.utexas.edu, for example). You may crosspost by including multiple addresses as Cc: entries (but see below). This gateway's continued availability is at the pleasure of the admins at UT-Austin, and is subject to going away at any time - and especially if forgeries and other net.abuses become a problem. You have been warned. Mailing Lists ============= In addition to the mailing lists that mirror the Usenet newsgroups, there also are a few that stand alone. These cover specific areas of ham radio, and discussion is focused on just those areas. The cq-contest mailing list is for discussions of contesting in ham radio. To join, send email with the word "subscribe" on a line by itself to cq-contest-request@tgv.com. The DX mailing list covers the finer points of DXing. This one is also joined by mailing "subscribe" on a line by itself, this time to dx-request@unbc.edu. There's also a VHF mailing list, for VHF operators of the weak signal persuasion. You can join this one be sending "subscribe vhf" on a line by itself to vhf-request@w6yx.stanford.edu. All of the following mailing lists are sponsored to the Boston Amateur Radio Club, as well as some others of local interest. Thanks to N1IST for the information. qrp-l: This is the qrp mailing list, previously maintained by Bruce Walker at Think.com. It is for discussions about the design, construction, and use of qrp (low power) radios and related equipment. arrl-ve-list: This is a one-way list, run by Bart Jahnke of the ARRL VEC, for announcements to VEs and VE teams. w1aw-list: ARRL bulletins, news, and information newsline-list: Redistribution of Amateur Radio Newsline letter-list: Redistribution of the ARRL Letter fox-list: Fox hunting and Radio Direction Finding fieldorg-l: ARRL field organization discussions ham-tech: Technical discussions and questions about Amateur Radio arrl-exam-list: amateur radio license examinations scheduled in the US and in some foreign areas. To sign up or inquire about these lists, send mail to listserv@netcom.com with the following in the body (subject is ignored) of the message. is the name of the list to subscribe to. To subscribe: subscribe To unsubscribe: unsubscribe For more information: help To post (to the two-way lists), send your message to @netcom.com Please do NOT send subscription requests to the mailing lists themselves; that doesn't work very often, and is very annoying to those on the list. Also, please keep your electronic mail address current with any mailing lists you subscribe to, as dealing with returned email is a nuisance for the person maintaining the mailing list. A Few Words on Crossposting =========================== Please do not crosspost messages to two or more groups unless there is genuine interest in both groups in the topic being discussed, and when you do, please include a header line of the form "Followup-To: group.name" in your article's headers (before the first blank line). This will cause followups to your article to go to the group listed in the Followup-To: line. If you wish to have replies to go to you by email, rather than be posted, use the word "poster" instead of the name of a group. Such a line appears in the headers of this article. One of the few examples of productive cross-posting is with the rec.radio.info newsgroup. To provide a filtered presentation of information articles, while still maintaining visibility in their home newsgroups, the moderator strongly encourages cross-posting. All information articles should be submitted to the rec.radio.info moderator so that he may simultaneously cross-post your information to the appropriate newsgroups. Most newsreaders will only present the article once, and network bandwidth is conserved since only one article is propagated. If you make regular informational postings, and have made arrangements with the moderator to post directly to the group, please cross-post as appropriate. -- Jay Maynard, EMT-P, K5ZC, PP-ASEL | Never ascribe to malice that which can jmaynard@admin5.hsc.uth.tmc.edu | adequately be explained by stupidity. "All is strange and vague." "Are we dead?" "Or is this Ohio?" -- Yakko and Dot Warner From lwbyppp@epix.net Thu Mar 21 13:41:07 1996 From: irwin@nai.net (Wayne Irwin) Newsgroups: rec.radio.amateur.antenna Subject: half wave verticals Date: 18 Mar 1996 21:35:18 GMT Message-ID: <4ikkum$9pf@a3bsrv.nai.net> Just wondering, has anybody made a comparison between the Cushcraft R7 and the Hy-gain DX-77? I'm thinking of getting one of these since many people have had very good luck with them, but want to get some feedback before making a decision. Any comments welcome From lwbyppp@epix.net Thu Mar 21 13:41:08 1996 From: Your Real Name Newsgroups: rec.radio.amateur.antenna Subject: Re:Hamstick" dipole Problems Date: 17 Mar 1996 19:22:51 GMT Message-ID: <4ihoqb$f22@grouper.Exis.Net> References: <4iev07$amc@inxs.ncren.net> dcole@weaver.guilford.k12.nc.us (Derrick Cole) wrote: > > Greetings! > > At the Charlotte HamFest last weekend, I purchased two 40M "HamStick" antenn as > (HF mobile whips?) consisting of a coiled mast and an extendable metal "whip ", > which, when adjusted, supposedly allow for tuning for a certain center > frequency. I also bought a mounting bracket so as to create a dipole from > the two 'sticks. > > Suffice to say, I've not had much luck. Initially, with the whips fully > extended, I could only achieve 3+:1 across 40M except for the upper 30KHz, > where I could get 1-8-2:1. > > Wanting a lower SWR in the lower 100KHz, I set out to actually read the > confusing instructions about the whip and tuning for a certain frequency. > Choosing a frequency of 7.1MHz, this implies an exposed whip length of > 39". I cut both whips to 39.5" (39" of which was exposed), tightened > everything up, tuned up on 7.1MHz, and now enjoy 5:1 SWR everywhere. > > Obviously, I've done something wrong. Can anyone offer ANY advice on such > a contraption? Where might I obtain replacement whips (which were originall y > 48.25" long)? What should I do? > > Thanks and 73, > Derrick I have done a lot of work with mobile whip used as very short dipoles. On 40 meters, it is possible to get a reasonable SWR (<2:1) over a bandwidth of abou t 35 KHz. My best results were with ProAm (Valor) whips, which include a matc hing capacitor in the package. The two whips used to make up the dipole are ea ch insulated from the mounting bracket. The anenna is fed with the 17-feet of coax as specified in the whips instruction sheet. Changing the length of the coax had a profound effect on matching as did the value of capacitor. I did find other lenght of coax which would permit a good match at a specific freque ncy. CW coverage on 80 for 40 meters was not possible with the whips supplied. They were far too short. Better, low SWR, bandwidth was observed on all the h igher band since the antennas were electrically longer. Now for the good news: When I got the whips tuned, the 40 meter antenna did a respectable job for a 16-foot dipole. Good luck with the project. Jim, W4THU jim@exix.net From lwbyppp@epix.net Thu Mar 21 13:41:09 1996 From: Zack Lau Newsgroups: rec.radio.amateur.antenna Subject: Re: HF dipole for VHF/UHF Date: Wed, 13 Mar 1996 13:17:13 -0500 Message-ID: <31471129.14E2@arrl.org> References: <4hsii6$1ct@news.asu.edu> <4i44b4$5d9@onramp.freeway.net> To: Peter Markham Peter Markham (WA4HEI)wrote: > > I have wondered about the possibility and practicality of using a > 75m dipole, center fed with 450 ladder (window?) line, on vhf/uhf. I > have never seen the subject touched upon in my limited printed resources, I had a similar system that seemed to work--I ran open wire (2 inch) to an 86 foot dipole strung above my 2nd floor apartment (one tree I used has since been cut down :-( ). Although the tuner was principally designed for 80 meters, it seemed to work on 6 meters, as it took only 15 months to collect the QSLs for VUCC running 3 watts PEP. I even worked a few double hop E skip contacts to the West Coast from New England. Zack KH6CP/1 From lwbyppp@epix.net Thu Mar 21 13:41:10 1996 From: Cecil Moore Newsgroups: rec.radio.amateur.antenna Subject: Re: HF dipole for VHF/UHF Date: 14 Mar 1996 22:50:28 GMT Distribution: world Message-ID: <4ia7rk$uaq@chnews.ch.intel.com> References: <4hsii6$1ct@news.asu.edu> <4i44b4$5d9@onramp.freeway.net> pmarkham@sun.lssu.edu (Peter Markham) wrote: >Anyone willing to share their insight or knowledge of the subject? > Hi Pete, An HF dipole on vhf/uhf would be extremely bi-directional. Most of the radiated power is off the ends with not much broadside coverage. It would be like having a beam that you can't rotate. 73, Cecil, KG7BK, OOTC (not speaking for my employer) From lwbyppp@epix.net Thu Mar 21 13:41:11 1996 From: Isaac Kohn Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.equpiment,rec.radio.amateur.misc,rec.radio.amateur.homebrew Subject: HF, multiband antenna, etc. for beginner -- PLEASE HELP! Date: Sun, 17 Mar 1996 20:00:51 -0600 Message-ID: <314CC3D3.347D@vertex.ucls.uchicago.edu> Greetings all, I am new to the world of ham radio (don't even have my license yet), and I'm working on setting up a station. I'm gonna need an antenna to work at least the entire HF range, and maybe thru 2m. I live on the second floor of a 2-flat, and space outside is limited... I've been figuring I'd put up a loop around my ceiling (approx. 12'x12') or on one wall (similar dimensions), use a transmatch, and hope for the best. Maybe someone out there has a better idea... It would be convenient if there were a way I could wire something up in my room or (for lower frequencies) outside my window... It may not be practical to raise anything up above the top of the building -- will this affect propagation in the HF range?? I _may_ be able to find a way to set up a horizontal dipole that is supported a few inches above the edge of the roof, so that obstructions are less of a problem. Anyone have any suggestions?? Also, I will need plans for a versatile, INEXPENSIVE Transmatch. I can probably tolerate somewhat high levels of SWR, if it will reduce design cost. Is it feasible to wire several toroid-core broadband transformers, and switch them in and out appropriately for each band?? I'd like not to have to retune the antenna every time I switch bands, and if I could have a knob that did that it would be quite nice....... PLEASE RESPOND (pref. by E-mail or E-mail+post) IF YOU CAN ANSWER ANY OF MY IGNORANT QUESTIONS!!! Thanks a lot everybody. 73's Isaac Kohn P.S. I actually am doing things in the wrong order, as I haven't built any sort of equipment that would utilize an antenna yet. If anyone has any diagrams/ideas for a receiver, and maybe a transmitter, that I could use for phone (at least AM, SSB would be nice), they would be much appreciated. Receiver might just be antenna, tank circuit shunting unwanted stuff to ground, single-diode detector, and high-gain AF AMP. This is good because I've already built a 1W output AF AMP, and it works great. Xmitter is tough because I only want to use one oscillator, but I want to span entire HF range. Prob. with both is switching components in tuned circuits for different bands.... Help is much appreciated. As you can see I am very unexperienced and am dying to get on the air. Thx again in advance! From lwbyppp@epix.net Thu Mar 21 13:41:12 1996 From: Buster Newsgroups: rec.radio.amateur.antenna Subject: How? 6 Meter J-Pole? Date: Thu, 21 Mar 1996 04:04:17 -0800 Message-ID: <315145C1.62B7@azstarnet.com> Been thinking about doing a 6-meter J-Pole I tried modifying the 2-Meter twin-lead design, but I think my feed points were too low on the antenna. I'd like to make one out of antenna whip. It's gonna be big. Preliminary estimates put the 3/4~ side at 150.5" and the 1/4~ matching stub at 50". Anyone have experience/measurements for different construction techniques. I've heard of some with 3/4" copper pipe. I'm A Little more interested in a finer whip, like Stainless Steel? Buster, KC7KMJ Tucson Arizona DM42 6 & 2 SSB From lwbyppp@epix.net Thu Mar 21 13:41:13 1996 From: Isaac Kohn Newsgroups: rec.radio.amateur.antenna Subject: Ignorant question: What's a G5RV??? Date: Mon, 18 Mar 1996 14:21:13 -0600 Message-ID: <314DC5B9.588F@vertex.ucls.uchicago.edu> Subject says it all.... What's a G5RV??? (antenna tuner??) 73's Isaac From lwbyppp@epix.net Thu Mar 21 13:41:14 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: Ignorant question: What's a G5RV??? Date: Wed, 20 Mar 96 08:50:28 GMT Message-ID: <4ioh6b$25j@crash.microserve.net> References: <314DC5B9.588F@vertex.ucls.uchicago.edu> <4imi61$4dp@fcnews.fc.hp.com> Cecil Moore wrote: >on 17m, the G5RV has 4 lobes each with 10dbi gain over ground Is that before or after subtracting the loss in the balun? ;) 73, Jack WB3U From lwbyppp@epix.net Thu Mar 21 13:41:15 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: Ignorant question: What's a G5RV??? Date: Wed, 20 Mar 96 09:21:02 GMT Message-ID: <4ioivl$25j@crash.microserve.net> References: <314DC5B9.588F@vertex.ucls.uchicago.edu> <4ils2n$ilh@newsbf02.news.aol.com> w8jitom@aol.com (W8JI Tom) wrote: >Some people hate G5RV's, and "write bad things on walls" about them. >But they are pretty good antennas for the effort, especially on 80, >40 and 20 meters. Guess I'm one of the graffiti guys, 'cause I still don't understand what the fuss is all about. In the configuration most people use these in, they're practically a dummy load on 15 & 10m. The only way to make this antenna perform well on all the bands is to ditch the balun and drive it with a balanced tuner. Once you do that, it's just a plain ole 102' dipole with a low-loss feed system, not a G5RV. 73, Jack WB3U From lwbyppp@epix.net Thu Mar 21 13:41:16 1996 From: Cecil Moore Newsgroups: rec.radio.amateur.antenna Subject: Re: Ignorant question: What's a G5RV??? Date: Tue, 19 Mar 96 21:28:51 -0500 Message-ID: References: <314DC5B9.588F@vertex.ucls.uchicago.edu> <4imi61$4dp@fcnews.fc.hp.com> Edward Lawrence writes: >for what it takes to bulid. I like them, but a full length dipole for each >band >will get out far better. (If you have the space.) I am now in an apartment, You're likely to get some arguments from that statement. For instance, on 17m, the G5RV has 4 lobes each with 10dbi gain over ground while a 17m dipole has two lobes each with 7dbi gain over ground. In addition, the G5RV has a lower take-off angle than the dipole. The dipole will not get out as well as a G5RV on 17m. Where did your "far better" opinion come from? 73, Cecil, KG7BK, OOTC From lwbyppp@epix.net Thu Mar 21 13:41:18 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: Ignorant question: What's a G5RV??? Date: Wed, 20 Mar 96 22:32:30 GMT Message-ID: <4iq1c0$7ca@crash.microserve.net> References: <4ioivl$25j@crash.microserve.net> <4ip56k$nfr@newsbf02.news.aol.com> w8jitom@aol.com (W8JI Tom) wrote: >jackl@pinetree.microserve.com (WB3U) writes: >>The only way to make this antenna perform well on all the bands is >>to ditch the balun and drive it with a balanced tuner. Once you do >>that, it's just a plain ole 102' dipole with a low-loss feed system, >>not a G5RV. >With a link coupled tuner, a system might improve a small amount over >a good choke balun. Dern, I knew sooner or later I was gonna get dragged into another of these G5RV balun threads. Oh well, can't resist. ;) Tom, you and I have discussed baluns here before, as well as in e-mail. In fact, I've been meaning to respond to your last message on the subject, but wanted to give it a little more thought first. Anyway, "good choke balun" is a pretty vague description for a device that can exhibit so many different characteristics. Let's examine the specifics a little more closely. First, I agree that a choke balun made of two parallel conductors wound on a rod or toroid provides the same function to the outside world as a choke balun that consists of ferrite beads slipped over coax, or a rolled-up section of coax. However, this only applies to a balun feeding the proper load impedance. If the load isn't correct, the characteristics of these three types of baluns will diverge. Let me give you an example of what I mean. Comparing the ferrite bead balun to a "wound" balun, the former suffers from significantly increased losses in the ferrite when load impedance is high. The reason for this is that RF current through the beads creates a single magnetic field in the ferrite. Increased voltage across the string of beads that results from increased feedpoint impedances causes the magnetic flux in each bead to also increase. The result is increased power loss within the ferrite, which in turn causes the beads to generate heat. Even with reasonable loads, this "single-ended" RF current can create considerable heat, which is why the smaller beads are recommended to be used only with Teflon coax. In contrast to this, the basic nature of the "wound" ferrite balun tends to prevent such losses, at least to a point. The winding of the choke consists of two parallel lines carrying opposing currents, therefore the magnetic flux generated by one wire is canceled by the flux generated by the other. So, under most conditions, flux losses in the core are much smaller than in the ferrite beads. It's still possible that certain conditions of impedance and frequency might produce a significant flux in the core though, if for no other reason than the loss of current balance in the conductors. As for *system* efficiency when the load impedance is high, even an assumption that balun losses are reasonable doesn't mean the baluns are functioning correctly or that the system will be efficient. The first thing that happens under these conditions is that the XL of the balun is no longer sufficient to provide the necessary choking action. Feedline balance subsequently deteriorates and the result is radiation from the feedline both fore and aft of the balun. This creates RF on the chassis of the transmitter, in addition to reducing the RF current that reaches the antenna. In my case, where the feedline is long and low to the ground, the effective loss in system efficiency could be severe under these conditions. The second area of system loss that occurs at high load impedances is the result of inter-winding capacitance. This becomes a more significant factor as the impedance increases, particularly at higher frequencies. In a worse-case scenario, the combination of low effective series reactance and high parallel capacitance probably renders the balun no more effective than running two bare wires through a Brillo pad! The result can be extreme SWR and increased loss in the coax preceding the balun. Even if the balun is inside the tuner housing and there's no coax, losses in the L/C components of the tuner may increase. It's like placing a near-short on the output of the tuner and loading it up! >But most of the improvement would come from loss reduction in the >feedline, not balun loss elimination (unless a lossy 4:1 type balun, >or an improperly designed choke balun, was used). Again, I think the terminology here is somewhat misleading. For instance, what does "improperly designed" mean, relative to an unpredictable load impedance? I suppose the balun could be made of 20 turns wound on a core the size of a cinder block, but that's not too practical. At some point, the designer has to decide where the cutoff is in terms of the range of load impedances the balun should be capable of driving. For one thing, as the diameter or number of turns is increased in order to increase the inductance and withstand higher impedances, the inter-winding capacitance also increases and reduces the bandwidth of the balun. The whole thing is a tradeoff between power handling, load accommodation and frequency response. Unfortunately, even when all the characteristics are optimized, the limitations imposed by available materials causes the real-world balun to fall far short of handling the real-world high-impedance antenna. >The user wouldn't notice any balun loss reduction if the tuner used a >balun, rather than link coupling! With unbalanced line part of the >way down, the common mode problem is no worse than it is with open >wire all the way down, and has to be handled at some point in the >system anyway! Why not move the balun up the pipe, and make the >feedline easy to handle? I can't comment on the first sentence because I'm not sure what it means. Regarding the common mode problem, I agree that it has to be handled at some point, but not that it should be handled by a balun. Also, I have some reservations regarding the possibility of increased loss in a long run of coax when a balun is used outside the tuner. The conditions that cause the balun to misbehave are the same ones that will increase that loss. What's bad for one is bad for the other, and mounting the balun in a remote location may compound the inefficiency that results from driving a high feedpoint impedance. >By avoiding a lossy 4:1 balun, and staying with a 1:1 choke, common >mode induced power loss can be controlled without excessive loss. "Controlled" is much too strong a word for the actual benefit derived from a choke balun in this situation. In addition, even if losses in the balun itself are reduced, losses external to the balun can still be significant. Given that those losses may be the sole result of the balun's inability to perform, the balun remains the culprit. Other than that, I agree with everything you said. 73, Jack WB3U From lwbyppp@epix.net Thu Mar 21 13:41:19 1996 From: raiar@inlink.com (Gary V. Deutschmann, Sr.) Newsgroups: rec.radio.amateur.antenna Subject: Re: J-pole Date: Wed, 13 Mar 1996 22:38:57 GMT Message-ID: <4i7ibi$g19@news1.inlink.com> References: wayneb@on-ramp.ior.COM (Wayne Barnhart) wrote: >I made a twin-lead J-pole last summer. Took great care to resonate the >thing then stuck it into some white pvc pipe. You gessed it, the swr >shifted. I later read where someone insulated the twinlead from the >inside of the pipe and all was well. I blv they used some non-conductive >foam that they split lengthwise and inserted the twinlead then fit the >whole thing into the plastic tube. >Wayne WB7WHI >Spokane, Wa. Why go to all the trouble and expense of putting a J-Pole inside of a PVC pipe, when you could have built a less conspicuous antenna from simple copper tubing or for almost invisibility stainless spring wire and be done with it? Gary From lwbyppp@epix.net Thu Mar 21 13:41:20 1996 From: wayneb@on-ramp.ior.COM (Wayne Barnhart) Newsgroups: rec.radio.amateur.antenna Subject: j-poles Date: 17 Mar 96 03:28:14 GMT Message-ID: Date: Wed, 13 Mar 1996 22:38:57 GMT From: raiar@inlink.com (Gary V. Deutschmann, Sr.) Subject: J-pole wayneb@on-ramp.ior.COM (Wayne Barnhart) wrote: >I made a twin-lead J-pole last summer. Took great care to resonate the thing then stuck it into some white pvc pipe. You gessed it, the swr shifted. I later read where someone insulated the twinlead from the inside of the pipe and all was well. I blv they used some non-conductive foam that they split lengthwise and inserted the twinlead then fit the whole thing into the plastic tube. >Wayne WB7WHI >Spokane,Wa. Why go to all the trouble and expense of putting a J-Pole inside of a PVC pipe, when you could have built a less conspicuous antenna from simple copper tubing or for almost invisibility stainless spring wire and be done with it? Gary ======================================= Gary, you missed the point of the thread. I do have a J-pole that I made out of 1/2 in. copper pipe and it works just too fine. Now should you be portable somewhere like a camping trip a twinlead j-pole hanging from the nearest tree branch also makes for a good antenna. Granted, it wont last as long as the copper pipe antenna but then again it isn't meant to. Wayne WB7WHI Spokane, Wa. From lwbyppp@epix.net Thu Mar 21 13:41:21 1996 From: jimkeesl@iserv.NET (Jim Keesler) Newsgroups: rec.radio.amateur.antenna Subject: John Kraus, W8JK Date: 14 Mar 96 00:23:00 GMT Message-ID: Last I knew, W8JK was hanging around the Ohio State University area--Columbus , Ohio in the United States--check his call at a call server or maybe try for an Ohio State Univ WEB site. Besides all his work on antennas, he was involved with the OSU "Big Ear" radio telescope and the Search for ExtraTerrestial Intelligence (SETI)--or something close to that name! 73, Jim K8EXF From lwbyppp@epix.net Thu Mar 21 13:41:22 1996 From: uncle@iap.net.au (Brian Field@iap.net.au) Newsgroups: rec.radio.amateur.antenna Subject: Re: ladder line and 6M antenna RESULTS? Date: Thu, 14 Mar 1996 17:16:01 GMT Message-ID: <4i9kac$im6@orange.iap.net.au> References: <4i3r4u$g52@newsbf02.news.aol.com> Reply-To: uncle@iap.net.au denoid95x@aol.com (DeNoid95X) wrote: >I have a quick question, I was wondering if anyone was using ladder line >from their transceiver to an antenna and if so what type of antenna and >the results you have experienced. I am using a 6M two element quad and >was curious of the results of such a system with ladder line 300/450 Ohm. >N9RLR/2 I've used it off and on, to a non-res dipole w/ an appropriately small tuner. Not sure what diff it would have made, as by the time you switch it over to a piece of coax, band condx would have changed. IF you need a long run, consider that ladderline is lossless compared to coax (and think about RECEIVING more than power loss of xmit.) Uncle Brian VK6BQN From lwbyppp@epix.net Thu Mar 21 13:41:23 1996 From: doughall@parsifal.nando.net (Doug Hall) Newsgroups: rec.radio.amateur.antenna Subject: Ladder line to rotatable dipole? Date: Fri, 15 Mar 1996 05:03:41 GMT Message-ID: <4iathm$eff@castle.nando.net> Reply-To: doughall@nando.net Hi all, Last month I dismantled an old (circa 1968) Mosley 2 element 40m beam. This wasn't a full size beam - it used center loading and shortened elements. I realized that if I took the loading coil off of one element it would make a great halfwave 30m dipole. So I did just that, and mounted it on the tower at 75 feet, just above the tribander. Presto - instant cheap rotatable dipole. It's fed with coax, and works great. Worked VK, ZL, and ZS the first night I put the thing up. So now I'm thinking that it would be nice to be able to use it on 40m and 17m as well. EZNEC says it would make a pretty good antenna on those bands. So here's the question: will I run into any problems if I run 450 ohm ladder line up to it in place of the coax and use my balanced tuner? I remember seeing pictures of beams fed with open wire feeders back in the 40s, so I know people used to do it. In my case I could run the ladder line up to the top of the tower along one of the guy cables (Phillystran, so they're non-conductive) but what about the rest of the way, past the tribander and up to the rotatable dipole? Any problems doing this? Given my feedline length, Mr. Smith and his magic chart tell me that I could get reasonable impedances on 40, 30, and 17, so it looks good from the shack end of things. Any words of wisdom? Anybody doing this now? 73, Doug, KF4KL From lwbyppp@epix.net Thu Mar 21 13:41:24 1996 Newsgroups: rec.radio.amateur.antenna From: gary@ke4zv.atl.ga.us (Gary Coffman) Subject: Re: Ladder line to rotatable dipole? Message-ID: <1996Mar17.192234.12417@ke4zv.atl.ga.us> Reply-To: gary@ke4zv.atl.ga.us (Gary Coffman) References: <4iatsd$f62@castle.nando.net> Date: Sun, 17 Mar 1996 19:22:34 GMT In article <4iatsd$f62@castle.nando.net> doughall@nando.net writes: >Hi all, > >So now I'm thinking that it would be nice to be able to use it on 40m >and 17m as well. EZNEC says it would make a pretty good antenna on >those bands. So here's the question: will I run into any problems if I >run 450 ohm ladder line up to it in place of the coax and use my >balanced tuner? I remember seeing pictures of beams fed with open wire >feeders back in the 40s, so I know people used to do it. In my case I >could run the ladder line up to the top of the tower along one of the >guy cables (Phillystran, so they're non-conductive) but what about the >rest of the way, past the tribander and up to the rotatable dipole? >Any problems doing this? Given my feedline length, Mr. Smith and his >magic chart tell me that I could get reasonable impedances on 40, 30, >and 17, so it looks good from the shack end of things. Any words of >wisdom? Anybody doing this now? Running the feedline up the guy will probably produce asymmetries in the patterns of all antennas mounted on the tower. And the mechanical problems of getting the open wire line around the rotating joint will be daunting. So I'd just feed it with low loss coax and accept the slight increase in VSWR losses over use of open wire line. Consult the chart in the Handbook, and you might be surprised how minor those additional losses can be for good low loss coax. Gary -- Gary Coffman KE4ZV | You make it, | Due to provider problems Destructive Testing Systems | we break it. | with previous uucp address es 534 Shannon Way | Guaranteed! | Email to ke4zv@radio.org Lawrenceville, GA 30244 | | From lwbyppp@epix.net Thu Mar 21 13:41:25 1996 Newsgroups: rec.radio.amateur.antenna From: gary@ke4zv.atl.ga.us (Gary Coffman) Subject: Re: lowband antennas Message-ID: <1996Mar17.184829.12256@ke4zv.atl.ga.us> Reply-To: gary@ke4zv.atl.ga.us (Gary Coffman) References: <4i6lj3$glk@flood.weeg.uiowa.edu> <4i73as$mda@crash.microserve.net> Date: Sun, 17 Mar 1996 18:48:29 GMT In article <4i73as$mda@crash.microserve.net> jackl@pinetree.microserve.com (WB 3U) writes: > sabinw@crpl.cedar-rapids.lib.ia.us (Bill W0IYH) wrote: > >>In the situation I am referring to, Kirchhoff's laws are satisfied >>more at the location of a *grounded* xmtr and not at the base of the >>antenna where we would prefer. > >I never thought it was preferable to ground the system at the base of >the vertical, only that it was important to prevent ground currents >from flowing through lossy earth. In fact, given the difficulty in >achieving a good RF connection to earth, I always assumed that the >"ground" reference in most Amateur vertical systems probably would >be the transmitter, not some puny ground rod at the base of the >vertical. If the current mirror is to be effective, it needs to be physically symmetric with the antenna, not the transmitter. Now if Earth is to serve as the current mirror, then the Earth connection should be at the antenna base, and not some puny ground rod either, but a proper ground field. There's no reason, other than ordinary electrical safety, why there should be a ground connection at the transmitter at all. >This brings up a point, though. Let's say that a vertical is >elevated and the shield of the coax is connected to radials. Let's >also assume that the radials are so long and so numerous that all >"ground current" is returned to the shield, and then to the >transmitter. > >Won't the efficiency and pattern of that antenna be identical to the >same system mounted at earth level? And won't the efficiency and >pattern be the same regardless of whether there's an actual earth >ground at the antenna (or transmitter)? If you aren't using Earth for the current mirror, connection to Earth is only useful for electrical safety. Elevated radials can decrease losses by isolating the current mirror from lossy Earth. Gary -- Gary Coffman KE4ZV | You make it, | Due to provider problems Destructive Testing Systems | we break it. | with previous uucp address es 534 Shannon Way | Guaranteed! | Email to ke4zv@radio.org Lawrenceville, GA 30244 | | From lwbyppp@epix.net Thu Mar 21 13:41:27 1996 From: sabinw@crpl.cedar-rapids.lib.ia.us (Bill W0IYH) Newsgroups: rec.radio.amateur.antenna Subject: Re: lowband antennas Date: 17 Mar 1996 20:15:40 GMT Distribution: world Message-ID: <4ihrtc$1dc0@flood.weeg.uiowa.edu> References: <4i6lj3$glk@flood.weeg.uiowa.edu> <4i73as$mda@crash.microserve.net>,<1996Mar17.184829.12256@ke4zv.atl.ga.us> Reply-To: SABINW@crpl.cedar-rapids.lib.ia.us In article <1996Mar17.184829.12256@ke4zv.atl.ga.us>, gary@ke4zv.atl.ga.us (Gary Coffman) writes: >In article <4i73as$mda@crash.microserve.net> jackl@pinetree.microserve.com (WB3U) writes: >> sabinw@crpl.cedar-rapids.lib.ia.us (Bill W0IYH) wrote: >> >>>In the situation I am referring to, Kirchhoff's laws are satisfied >>>more at the location of a *grounded* xmtr and not at the base of the >>>antenna where we would prefer. We all know what the correct situation is supposed to be for the vertical antenna at ground level. There is no need to keep on arguing about that ad infinitum. My question is, what is going on in the less-than-ideal situation where the ground/radial setup *at the antenna* is inadequate? I have read that high power low frequency stations worry about this a great deal. I am sure that my two recent posts have spelled this out very clearly. The fact is that xmtrs are grounded, as they should be. If the ground radial system is poor, as it might be in amateur setups, what does the ground return path to the xmtr look like. If all of the radiator displacement currents do not return to the xmtr through the coax braid some problems can occur. What are these problems? How do we detect the presence of a problem? One clue is that the sum of return currents ***at the base of the antenna*** may not equal the current into the radiator. Bill From lwbyppp@epix.net Thu Mar 21 13:41:28 1996 From: sabinw@crpl.cedar-rapids.lib.ia.us (Bill W0IYH) Newsgroups: rec.radio.amateur.antenna Subject: lowband antennas Date: 13 Mar 1996 14:20:19 GMT Distribution: world Message-ID: <4i6lj3$glk@flood.weeg.uiowa.edu> Reply-To: SABINW@crpl.cedar-rapids.lib.ia.us >I'm giving a talk on low-band antenna modeling As you know, there has been some discussion about the management of ground and radial currents on ground-mounted verticals. It seems to me that subject would be a good subject for further study under scientific conditions. In particular, the possibility of alternate ground return paths to a transmitter ground, other than through the coax feedline, is a definite possibility, and also maybe a source of trouble. Also, the coax braid can act as a radial, with unknown consequences. Terman's 1943 Handbook speaks of the necessity of "gathering all ground currents to the base of the antenna and returning them to the transmitter through the transmission line." This question pops up in particular when the radial system is inadequate. In the situation I am referring to, Kirchhoff's laws are satisfied more at the location of a *grounded* xmtr and not at the base of the antenna where we would prefer. For someone with the facilities and training, this would be a good topic for Amateur research. From lwbyppp@epix.net Thu Mar 21 13:41:29 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: lowband antennas Date: Wed, 13 Mar 96 18:10:41 GMT Message-ID: <4i73as$mda@crash.microserve.net> References: <4i6lj3$glk@flood.weeg.uiowa.edu> sabinw@crpl.cedar-rapids.lib.ia.us (Bill W0IYH) wrote: >In the situation I am referring to, Kirchhoff's laws are satisfied >more at the location of a *grounded* xmtr and not at the base of the >antenna where we would prefer. I never thought it was preferable to ground the system at the base of the vertical, only that it was important to prevent ground currents from flowing through lossy earth. In fact, given the difficulty in achieving a good RF connection to earth, I always assumed that the "ground" reference in most Amateur vertical systems probably would be the transmitter, not some puny ground rod at the base of the vertical. This brings up a point, though. Let's say that a vertical is elevated and the shield of the coax is connected to radials. Let's also assume that the radials are so long and so numerous that all "ground current" is returned to the shield, and then to the transmitter. Won't the efficiency and pattern of that antenna be identical to the same system mounted at earth level? And won't the efficiency and pattern be the same regardless of whether there's an actual earth ground at the antenna (or transmitter)? 73, Jack WB3U From lwbyppp@epix.net Thu Mar 21 13:41:30 1996 From: Will Flor Newsgroups: rec.radio.amateur.antenna Subject: MFJ "Portable Antenna" Date: 18 Mar 1996 05:56:54 GMT Message-ID: <4iitv6$ob4@news.inc.net> MFJ sells an interesting device they call a "portable antenna" for HF. Actual ly, it is a 54" whip with an antenna tuner built into its base. It's relatively cheap a nd so, while visiting AES the other day, I bought one "for the heck of it." I'm actu ally quite impressed with it - it works far better than I'd ever believe a 54" base -loaded whip would work at ground level. I can definitely get a match and low SWR on 40m thru 10m, and the amazing thing is - it transmits and receives fairly well, too, so not all of the low SWR is due to feedline loss ;-) Has anyone else here ever used this device? I'd really like to modify it for use on lower frequencies - I know, I know, th is isn't really a good antenna for 4MHz work, but I think it would be possible. Do any antenna/antenna tuner gurus here know if just lengthening the antenna would pe rmit this, or is the limiting factor built into the tuner? One idea I had was to c onnect a wire to the top of the whip (disconnectable) and run it to a tree or other sup port. I realize that if you do this you might just as well take a regular antenna tune r into the field and attach a random wire and be done with it, but I'm fascinated by my new toy. Any ideas? 73 de Will KB9JTT "Badger 323" willf@rrgroup.com From lwbyppp@epix.net Thu Mar 21 13:41:31 1996 From: Douglas Finke <74740.3422@CompuServe.COM> Newsgroups: rec.radio.amateur.antenna Subject: Re: MFJ HF VERTICALS??? Date: 17 Mar 1996 20:03:33 GMT Message-ID: <4ihr6l$s7n$1@mhafn.production.compuserve.com> I have an MFJ 1798 vertical that goes from 80 to 2 meters. It works pretty well, but assembly is probably more time-consuming that some of the others. And tuning requires some care. But, in theory at least, it should have slightly better results than some of the others because it is top fed instead of bottom fed. This provides a lower angle of radiation because the current maximum is at the highest part of the antenna. Bandwidth is good. It covers the entire bandwidth on 30,20,18,15,12, and 10. But is limited to about 30 Khz. on 80 and 40. (But even this is not a problem if you have a tuner.) Regards, Doug, K9DF -- Douglas Finke From lwbyppp@epix.net Thu Mar 21 13:41:32 1996 Newsgroups: rec.radio.amateur.antenna From: lloyd korb Subject: Mobile Antenna Spacing Message-ID: <1996Mar18.164730.884@picker.com> Date: Mon, 18 Mar 1996 16:47:30 GMT I plan on runnning my Yaesu FT-736R from my van. I can space the 6 & 2 mtr antennas about 8 feet apart on the roof. I'm concerned that the close proximity of the two antennas will cause excessive RF to receiver front ends. Does anyone have experience with a similar installation? 73, Lloyd K8DIO KORB@XRAYMKT.PICKER.COM From lwbyppp@epix.net Thu Mar 21 13:41:33 1996 Newsgroups: rec.radio.amateur.antenna From: lloyd korb Subject: Mobile Antenna Spacing Message-ID: <1996Mar18.164736.949@picker.com> Date: Mon, 18 Mar 1996 16:47:36 GMT I plan on runnning my Yaesu FT-736R from my van. I can space the 6 & 2 mtr antennas about 8 feet apart on the roof. I'm concerned that the close proximity of the two antennas will cause excessive RF to receiver front ends. Does anyone have experience with a similar installation? 73, Lloyd K8DIO KORB@XRAYMKT.PICKER.COM From lwbyppp@epix.net Thu Mar 21 13:41:34 1996 Newsgroups: rec.radio.amateur.antenna From: lloyd korb Subject: Mobile Antenna Spacing Message-ID: <1996Mar18.165015.1244@picker.com> Date: Mon, 18 Mar 1996 16:50:15 GMT I plan on running my Yaesu FT-736R from my van. I can space the 6 & 2 mtr antennas about 8 feet apart on the roof. I'm concerned that the close proximity of the two antennas will cause excessive RF to the receiver front ends. Does anyone have experience with a similar installation? 73, Lloyd K8DIO KORB@XRAYMKT.PICKER.COM From lwbyppp@epix.net Thu Mar 21 13:41:35 1996 From: "George J. Molnar" Newsgroups: rec.radio.amateur.antenna Subject: Re: Mobile Antenna Spacing Date: Mon, 18 Mar 1996 22:07:06 -0700 Message-ID: <314E40FA.6437@interealm.com> References: <1996Mar18.165015.1244@picker.com> To: lloyd korb lloyd korb wrote: > > I plan on running my Yaesu FT-736R from my van. I can space the 6 > & 2 mtr antennas about 8 feet apart on the roof. I'm concerned that > the close proximity of the two antennas will cause excessive RF to > the receiver front ends. Does anyone have experience with a similar > installation? > Until recently, I ran two rigs in my Jeep, one for HF, the other on 2m. antennas were about 5 feet apart, close to opposite corners of the rear. No problems were noted running up to 50 watts on either HF or 2m. I never ran 2 and 6, but don't imagine there'll be much to worry about, unless you get out the 8877's and build an amplifier to put in the trunk! Happy mobiling... -- George J. Molnar Highlands Ranch, Colorado Amateur Radio: KF2T@N0QCU.#NECO.CO.USA.NOAM http://www.interealm.com/p/gmolnar/index.html From lwbyppp@epix.net Thu Mar 21 13:41:37 1996 From: JRCLARK@SunBelt.Net (Rick Clark) Newsgroups: rec.radio.amateur.antenna Subject: Re: Mobile Antenna Spacing Date: Wed, 20 Mar 1996 16:22:14 GMT Message-ID: <4ipbb1$pu9@news1.sunbelt.net> References: <1996Mar18.164730.884@picker.com> lloyd korb wrote: >I plan on runnning my Yaesu FT-736R from my van. I can space the 6 >& 2 mtr antennas about 8 feet apart on the roof. I'm concerned that >the close proximity of the two antennas will cause excessive RF to >receiver front ends. Does anyone have experience with a similar >installation? >73, Lloyd K8DIO >KORB@XRAYMKT.PICKER.COM This is the first time I have tried to post a reply, so I hope that it works. Loyd, I have been running "multiple mobiles" for quite some time. I work in law enforcement as well as being an active ham, and my patrol car is what is most often refered to as a rolling cactus. I normaly run : 1- a Motorola Syntor-X VHF police radio (153-160 Mhz) 2- a Kenwood TM-721 dual band 144 & 440 Mhz ham radio 3- a Radio Shack PRO 32 scanner (usually scanning other agencies on 153-160) 4- a Uniden HR-2510 10m ham radio 5- a GE compact C.B. 6- a Motorola cellular telephone All of the antennas are in close proximity on the trunk and roof of the car, and the only problems that I have are that the police radio will de-sense the 2m, and the 10m will sometimes cause feedback in the scanner (and I'm working on that !) I have had no trouble with the high levels of RF doing any sort of damage to any of the equipment (I was worried abaut that at first, too) , even though some are in or near the same bands. Probobly the best advice is to space the antennas as far apart as you can, don't worry about it, and have fun! 73, and Happy Mobiling, Rick Clark KE4HIL From lwbyppp@epix.net Thu Mar 21 13:41:38 1996 Newsgroups: rec.radio.amateur.antenna From: wa2ise@netcom.com (Robert Casey) Subject: Re: My homemade J-pole works like a charm Message-ID: References: <314ABADD.4926@pints.com> Date: Sun, 17 Mar 1996 00:44:07 GMT In article <314ABADD.4926@pints.com> fortnum@pints.com writes: >I have installed my J-Pole that I made from a magazine article, and I = > >had the SWR measured; = > > ><1.1 on 2 meter >1.3 on 440 > >Works like a charm, even with 85 feet of coaxial (RG-58). I am pushing = >5.5 watts through it, from a new Kenwood Handheld TH-79AD, and 3 amp = >power supply. Works like a charm. I can get over 100 km away. I am = >located in Guelph, Ontario, about 1 hour west of Toronto. >I am just trying to get it higher, which might mean more coaxial. = >Perhaps an amplifier might work also. Any ideas for a dual amp for up = >to 5.5 watts input? >Cheers. Be aware that RG58 is lossy at that length and at 2M and 440. And that lossyness will make your antenna's SWR look better (the lossy cable will absorb more reflection as well as the forward power. You're probably loosing 2,5 dB forward, and whatever reflection the antenna is reflecting back (of the RF that made it thru the first time) is being attenuated another 2.5 dB. So the reflection will look 5 dB lower then it really is with lossless coax connected to the antenna. Making contacts over 100 Km ain't bad, though.... From lwbyppp@epix.net Thu Mar 21 13:41:39 1996 Newsgroups: rec.radio.amateur.antenna From: Tom Skelton Subject: Re: need help with 160 meter receiving antenna Message-ID: Reply-To: Tom.Skelton@ColumbiaSC.ATTGIS.COM (skeltt) References: <4hmulg$6qu@insosf1.netins.net> Date: Tue, 12 Mar 1996 17:24:58 GMT >==========Richard Geifman, 3/7/96========== > >During the cq 160 meter contest we were able to get out quite well. >We had a sloper and a dipole off a grain elevator withh an inverted >"V" at the top, almost 200 feet. Our problem was that we were not >able to receive as well. I think that we were getting too much signal >with a noise level of S+10. > -snip- Richard: If you want to get REAL serious about low band work, and you must if you went to the trouble to get an antenna 200 ft off the ground, then procure one or both of these resources: 1. The Low Band DX Handbook, by John/ON4UN, available from the ARRL 2. The Beverage Antenna Handbook, by Vic/W1WCR The Beverage Antenna Handbook is $15.95 (I just ordered one), and ON4UN's book is around $20 I think. I can attest that ON4UN's book is a timeless resource that will cover the answers to more questions that you will ever imagine. I haven't read W1WCR's book yet, but I have been assured it is THE RESOURCE on Beverage antennas. Since you didn't mention Beverage antennas in your questions, maybe you're not familiar with them. In a nutshell, a Beverage (named after Harold Beverage) is a low-noise receiving antenna that is "long." Optimum length for 160 meters seems to be around 1050 ft, and it is 8 to 12 ft off the ground. For unidirectional use, terminate the far end to ground in a 500 to 600 ohm non-inductive resistor. Feed the Beverage with 50 ohm coax through a 9:1 unun (unbalanced to unbalanced) or use an L-network (the unun is easier). If you can't swing 1050 ft, at least go for 400 to 500 ft. I used a 350 ft Beverage for 80 meters and it was shocking what you DON'T hear down in the noise on your xmit antenna. 9M2AX long path on 80 meters made me a believer. QSL is on the wall. :-) By the way, if you have a spare 200 ft silo you want to lend out I would be VERY HAPPY to borrow it!!!! 73, Tom WB4iUX OF COURSE I HAVE NO FIDUCIARY INTEREST IN EITHER OF THESE PUBLICATION. BLAH BLAH BLAH, ETC. From lwbyppp@epix.net Thu Mar 21 13:41:41 1996 From: thompson@atl.mindspring.com (David L. Thompson) Newsgroups: rec.radio.amateur.antenna Subject: Re: need help with 160 meter receiving antenna Date: Mon, 18 Mar 1996 02:49:35 GMT Message-ID: <4iiica$gv2@B1FF.mindspring.com> References: <4hmulg$6qu@insosf1.netins.net> Reply-To: thompson@atl.mindspring.com rgeifman@netins.net (Richard Geifman) wrote: >During the cq 160 meter contest we were able to get out quite well. >We had a sloper and a dipole off a grain elevator withh an inverted >"V" at the top, almost 200 feet. Our problem was that we were not >able to receive as well. I think that we were getting too much signal >with a noise level of S+10. >Can anyone suggest a good receiving antenna. We have the height and >room for almost anything. Does anyone have any information on >receiving loops or coax cable receiving loops? >Any information you could give would be appreciated. >KB0KRO Richard Geifman >Rgeifman@netins.net Some people (such as myself) don't have room for beverages or even several EWE antennas. I have 1/2 acre and cannot put antennas in my from yard at a low level. An alternative is to use a shielded link loop made from coax. The best article was by Mike Crabtree AB0X in the August 1989 CQ. The loop is one continuous piece of coax made into a loop. Attached the center conductor of the far end to a point on the coax shield leaving the shield open at that point then run the end of the coax into the receiver. Mike and I have worked on this and find that its best to use a pre-amp with gain control and do not use an antenna tuner as it introduces TV noises and remote telephone intermod. Mikes version was only 175' and my version is 300feet (I used RG58). Mike was going to use a hardline version . Mine is laid horizontal on my roof and runs through part of the trees in my back yard. W4UW used a vertical version (1988 CQ). If you have the room beverages are the best if not try this scheme. I hear much better than I transmit on 160 most times! 73, Dave K4JRB From lwbyppp@epix.net Thu Mar 21 13:41:42 1996 From: mhh@waikato.ac.nz (mhh) Newsgroups: rec.radio.amateur.antenna Subject: NEEDING INFO PLEASE! Date: 13 Mar 1996 03:03:10 GMT Message-ID: <4i5dtf$1c14@thebes.waikato.ac.nz> Reply-To: mhh@waikato.ac.nz Gidday All, Lovely day here in the Waikato, New Zealand. I am interested in learning more about antenna theory, in all bands. Any recommendations on fairly recent publications? I serve in the Royal NZ Corps of Signals, and so have experience in OPERATING VHF and HF and UHF gear of various sorts, including multichannel and long distance comms. I'd just like to know more about the "guts" of everything (is there a FAQ?!). Also, what's the story with comms between the Shuttle and ground in the South Pacific? Any ideas of loc. or freq.? Catchya soon. mhh@waikato.ac.nz [OUT] /\/\ From lwbyppp@epix.net Thu Mar 21 13:41:43 1996 From: w5gyj@primenet.com (James E. Bromley) Newsgroups: rec.radio.amateur.antenna Subject: Re: OOTC Date: 12 Mar 1996 14:16:01 -0700 Message-ID: References: <4606E8C2@MHS> In article <4606E8C2@MHS> cowanr@isma8.monmouth.army.mil (Roland WF4P) writes: >Could someone tell me what an OOTC is? >Is that an EE on steriods or or what? No, it's a ham on Geritol. ;-) (Hi Cecil!) Jim, W5GYJ Glendale, AZ From lwbyppp@epix.net Thu Mar 21 13:41:44 1996 From: wa5dxp@mail.sstar.com (Jim Overstreet) Newsgroups: rec.radio.amateur.antenna Subject: re:organic verticals Date: Tue, 19 Mar 1996 14:39:50 GMT Message-ID: <4imh1m$1ljs@tetsuo.communique.net> I tried to send a "follow-up", but never did see it appear, so will try again. I believe 73 magazine had an article many years ago about using trees as vertical radiators, with mention that special forces had developed a way to use them in emergency. If I remember, they were fed with a magnetic-loop coupling, untuned, similar to the way the new mini-loop antennas. The article hinted at their use in Vietnam, so perhaps some of the Veterans can elaborate. I suspect the special forces comm manuals may have info on this. I think the coupling loop was wound like a toroid that would encircle the tree, and position of this loop above ground was determined by frequency, which would sort of be like feeding a flagpole. Anyone else remember the article(s)? From lwbyppp@epix.net Thu Mar 21 13:41:44 1996 Newsgroups: rec.radio.amateur.antenna From: n4lq@iglou.com (Steve Ellington) Subject: Re: Organic verticals again Message-ID: References: <4i9n40$a70@rover.ucs.ualberta.ca> <4ia1ro$lgc@newsbf02.news.aol.com> Date: Fri, 15 Mar 1996 00:54:52 GMT : 1.) In Florida a GASH raises efficiency and eliminates ground loss. : 2.) In Texas a cage increases antenna efficiency enough to surpass a full : size antenna. : 3.) In California photons (still radiation) bombard tubes on standby : causing electron avalanches. : 4.) In VK, live trees can be used for HF antennas. 5. In Carolina a feedline radiates a strong dx signal. 6. In NH a 17ft vertical is 1/2 wavelength on 40 meters. 7. In MS. A lumpy stick becomes a 9 band vertical. -- Steve Ellington N4LQ@IGLOU.COM Louisville, Ky From lwbyppp@epix.net Thu Mar 21 13:41:46 1996 From: wa5dxp@mail.sstar.com (Jim Overstreet) Newsgroups: rec.radio.amateur.antenna Subject: Re: Organic verticals again Date: Sat, 16 Mar 1996 13:44:03 GMT Message-ID: <4iegkv$3as@tetsuo.communique.net> References: <4hvmdk$suk@rover.ucs.ualberta.ca> <4i1cpk$90o@newsbf02.news.aol.com> w8jitom@aol.com (W8JI Tom) wrote: >In article <4hvmdk$suk@rover.ucs.ualberta.ca>, rwa@cs.athabascau.ca (Ross >Alexander) writes: >> just went out and measured the resistance between two plated 8" lag >>screws driven into a meter of green aspen, about 30 in cm diameter. >>> >>regards, >>Ross ve6pdq >Hi Ross, >You're measurement proves a good point. The tree can't contribute any >useful amount to radiation. >We all know the efficiency is directly tied to the ratio of loop radiation > >Common sense tells us that if a tree was useful as any type of radiator at >all, wooded areas would kill vertically polarized LF and HF signals. We >know that isn't true at all from day to day experience. >The only thing that makes sense is the feedline or gamma wire must be the >real source of the radiation. I suspect the theory came from a common >joker, terribly inexperienced antenna guy, or perhaps a mass consumer of >organic substances. Hi Fellows: I think trees were used as antennas in Vietnam in emergency situations, and the tramsmitter was magnetically coupled to the tree a certain distance above the ground depending on the frequency. 73 magazine had an article on this many years ago, and perhaps some military communications manuals would give more details. If you do discover the trick, how about posting it here. Perhaps some jungle-comms types are still around to explain it to us here. If I remember, the tree was fed with a toroid-wound coupling loop of just a few turns, untuned if I remember, vaugely similar to the way the Iso-Loop is fed. From lwbyppp@epix.net Thu Mar 21 13:41:47 1996 Newsgroups: rec.radio.amateur.antenna From: gary@ke4zv.atl.ga.us (Gary Coffman) Subject: Re: Organic verticals again Message-ID: <1996Mar17.175715.11850@ke4zv.atl.ga.us> Reply-To: gary@ke4zv.atl.ga.us (Gary Coffman) References: <313E4F7F@central.advance.com.au> <4hvmdk$suk@rover.ucs.ualberta.ca> <1996Mar11.020108.7926@ke4zv.atl.ga.us> <4i7rm5$d14@rover.ucs.ualberta.ca> <4i9n40$a70@rover.ucs.ualberta.ca> Date: Sun, 17 Mar 1996 17:57:15 GMT In article <4i9n40$a70@rover.ucs.ualberta.ca> rwa@cs.athabascau.ca (Ross Alexa nder) writes: >Anyone got an old General >Radio admittance bridge they'd part with for a reasonable amount? :) I saw one for sale yesterday at a hamfest. It was priced right, but didn't sell. Contact Robert Garcia, KD4JRT, for more info. His number is 770-977-5701. I've bought test equipment from him before, and he stands behind the equipment (money back guarantee). I bought a really nice Wavetek sweeper from him yesterday. Look out cavities, I'm dangerous now. :-) Gary -- Gary Coffman KE4ZV | You make it, | Due to provider problems Destructive Testing Systems | we break it. | with previous uucp address es 534 Shannon Way | Guaranteed! | Email to ke4zv@radio.org Lawrenceville, GA 30244 | | From lwbyppp@epix.net Thu Mar 21 13:41:48 1996 From: rwa@cs.athabascau.ca (Ross Alexander) Newsgroups: rec.radio.amateur.antenna Subject: Re: Organic verticals again Date: 14 Mar 1996 18:04:48 GMT Message-ID: <4i9n40$a70@rover.ucs.ualberta.ca> References: <313E4F7F@central.advance.com.au> <4hvmdk$suk@rover.ucs.ualberta.ca> <1996Mar11.020108.7926@ke4zv.atl.ga.us> <4i7rm5$d14@rover.ucs.ualberta.ca> rwa@cs.athabascau.ca (Ross Alexander) writes: >Just went outside with my Autek RF analyst and did some more >measurements. Got 1300 ohms at 3.5 Mhz, 550 ohms at 7.15 Mhz, >230-ish ohms at 20m. That's per foot. Forgive me the faux pas of following-up to my own post, but the more I think about this, the more I'm convinced that I was probably only measuring the reactance of a capacitor made of two lag screws with 12" of aspen dielectric. The Autek doesn't indicate complex Z, it displays |Z|. That tree measurement could easily be 100k-j230 at 20m; I need to go back with a proper noise bridge to get a vector measurement. (Is anyone else as annoyed as I am with the current generation of fancy antenna measurement gadgets the have popped up lately promising all kinds of wondrous info? Yet none of them seem to be able to measure complex impedance; so it's back to the klunky MFJ noise bridge I bought years ago to get that answer. Anyone got an old General Radio admittance bridge they'd part with for a reasonable amount? :) regards, Ross ve6pdq -- Ross Alexander, ve6pdq -- (403) 675 6311 -- rwa@cs.athabascau.ca From lwbyppp@epix.net Thu Mar 21 13:41:49 1996 Newsgroups: rec.radio.amateur.antenna From: n4lq@iglou.com (Steve Ellington) Subject: Re: Organic verticals again Message-ID: References: <313E4F7F@central.advance.com.au> <4hvmdk$suk@rover.ucs.ualberta.ca> <1996Mar11.020108.7926@ke4zv.atl.ga.us> <4i7rm5$d14@rover.ucs.ualberta.ca> <4i9n40$a70@rover.ucs.ualberta.ca> Date: Thu, 14 Mar 1996 18:50:29 GMT Look. If you saps want to pine away all day then be my guest. This poor guy went out on a limb to root out new antenna techonolgy and some of you are already board. I shall em-bark on a mission to spruce up my antenna farm here. Perhaps some phased elms? Why woodent this work? Hey, they been makin beams outta wood for years! -- Steve Ellington N4LQ@IGLOU.COM Louisville, Ky From lwbyppp@epix.net Thu Mar 21 13:41:49 1996 From: w8jitom@aol.com (W8JI Tom) Newsgroups: rec.radio.amateur.antenna Subject: Re: Organic verticals again Date: 14 Mar 1996 16:08:08 -0500 Message-ID: <4ia1ro$lgc@newsbf02.news.aol.com> References: <4i9n40$a70@rover.ucs.ualberta.ca> In article <4i9n40$a70@rover.ucs.ualberta.ca>, rwa@cs.athabascau.ca (Ross Alexander) writes: >Forgive me the faux pas of following-up to my own post, but the more I >think about this, the more I'm convinced that I was probably only >measuring the reactance of a capacitor made of two lag screws with 12" >of aspen dielectric. The Autek doesn't indicate complex Z, it >displays |Z|. That tree measurement could easily be 100k-j230 at 20m; >I need to go back with a proper noise bridge to get a vector >measurement. One thing this confirms is my theory that the furter west you go, the weirder science becomes. Let's test the theory: 1.) In Florida a GASH raises efficiency and eliminates ground loss. 2.) In Texas a cage increases antenna efficiency enough to surpass a full size antenna. 3.) In California photons (still radiation) bombard tubes on standby causing electron avalanches. 4.) In VK, live trees can be used for HF antennas. Oh my Goodness, the line crosses the Bermuda triangle! ;-) From lwbyppp@epix.net Thu Mar 21 13:41:51 1996 From: richardm@advance.COM.AU (Richard Murnane x2175) Newsgroups: rec.radio.amateur.antenna Subject: Organic verticals again Date: 15 Mar 96 22:00:00 GMT Message-ID: <31491603@central.advance.com.au> Ross Alexander ve6pdq (rwa@cs.athabascau.ca) wrote: > I think our VK friend made his QSOs via "feedline" (I sneer-quote > feedline here because I doubt he was feeding anything into that tree) > radiation. The last bit about other trees does tip the intent of the > article, though; it must have been a 1 April effort. "Amateur Radio" magazine is not noted for such subtle humour: speaking as one who has written for them under the pseudonym of Dr. Owen Lee Kidden VK1APR, I can tell you they would have clearly labelled it "Humour", or at least printed a note to the effect that it was a joke, were it so. Or perhaps AR's editorial policy has changed recently. :-) In any case, this was the March edition of the mag. A couple of years ago, "Dr. Kidden", well-known at the Australian National University for his expertise in spread spectrum communications, complained bitterly of antiquated government regulations requiring frequency hopping Amateur stations to identify using voice each time their station changed frequency. An explanatory note got added to my article lest any controversial debate arise over the "requirement". Perhaps it's a reflection on AR's readership, or Australian Amateurs, or all Amateurs? I once did an story about a code-free HF licence that did not require operators to sit for exams or anything. I even said that the allocation for this service had been opened up in the 11 metre band, with modes limited to AM and SSB voice. I was of course suggesting (without saying so directly) that people whinging for a code free HF Amateur licence class should go out and buy themselves a CB...yet, at least one Amateur club (in VK3, I think) reprinted the item in their club newsletter *as a serious news item*.... Alas, Dr Kidden has been too busy with private research in recent months, so no joke articles from him next month. My apologies: the subject matter of this message has been only tangentially related to antennas, so to let me rescue it by asking about people's experience with the Terlin Outbacker HF whip. I have bought one but haven't yet installed it (I don't have a car big enough! :-) Before I ordered it, I got a promotional video (American too - odd, considering Terlin is Australian), which showed it being used portable, i.e. without the benefit of a 4-wheeled ground planebeneath it, but instead using a counterpoise. Have any of you used this of any other "off-car" configurations succesfully? Regards, Richard From lwbyppp@epix.net Thu Mar 21 13:41:52 1996 From: Dietrich Morgenstern <76050.1341@CompuServe.com> Newsgroups: rec.radio.amateur.antenna Subject: Re: OSCAR 2mt DwnLnk Date: Thu, 14 Mar 1996 08:19:11 +0100 Message-ID: <3147C86F.1725@CompuServe.com> References: <4i6vl7$ddf@newsworthy.West.Sun.COM> Reply-To: 76050.1341@CompuServe.com Tony Angerame - Sun SSE wrote: > > only 20 feet or less away from the shack. I am contemplating a six turn heli x but > haven't worked out the mechanical details. (Need to get to Home Depot hihi). As an > alternative antenna I am thinking of the KLM,Hy-gain or M2 Circular polarize d yagis. > I have notice they make both a large and a smaller model (15ele vs 11 or so) . Which > one is my best bet? Should I go for the higher or lower gain model? I like t he idea > of switching RHCP and LHCP but I'm not sure how important it is? Slowly but shurely > and before the sunspots are back! > > TIA > > Tony WA6LZH Tonz> - Do NOT try to build a helix for 2m. It would be too big. - Use the 2x11 el antenna from M2. They are by far the best Oscar antennas (at least over here in Europe). They especially are mechanically very stable, have low wind resistance and the smallest side lobes I have ever seen. They are very corrosion proff. I am using them in a high alpine location with occasional very bad werather and up to now they have stood up well. - The M2 Antennas have fixed right hand polarization that can not be switched. In my experience with Oscars 10 and 13 that is not a big drawback. During several years of Oscar 13 work with switchable polarization I did not find that very useful. - Use a good preamp close to the antenna and good N-type water proof connectors. - I do not have any experience with KLM antennas but the consensus on the satellites seems to be that M2 are slightly better if compared with the same price class. Somebody told me that the M2 antennas were designed by a gentleman who did the KLM antennas before. - The 11 el is entirely sufficient for Oscars 10 and 13 if the noise figure of your receiver is determined by the preamp. - Use a digital noise reduction filter. Hope this will help. 73 Dietrich DJ1VA From lwbyppp@epix.net Thu Mar 21 13:41:53 1996 From: johnn0isl@aol.com (John N0ISL) Newsgroups: rec.radio.amateur.antenna Subject: Re: Portable HF ant. suggestions? Date: 13 Mar 1996 00:11:32 -0500 Message-ID: <4i5le4$8dd@newsbf02.news.aol.com> References: <3145D343.5946@best.com> Reply-To: johnn0isl@aol.com (John N0ISL) I've been using a Fritzell Windom for about a year for portabe operations.. Loads on 10 through 80 with no tuner (except 15 and 30 meters).. Its about 105 feet long. Works very well when you can get the feedpoint at about 32 feet.. Good luck... N0ISL John John Douglas, N0ISL AX.25 N0ISL@KZ7I.#MSP.MN.USA.NOAM I'm in Minnesota only because I must be somewhere! From lwbyppp@epix.net Thu Mar 21 13:41:54 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: Portable HF ant. suggestions? Date: Wed, 13 Mar 96 17:54:36 GMT Message-ID: <4i72co$mda@crash.microserve.net> References: <3145D343.5946@best.com> Mike James wrote: >Can anyone suggest a good, portable HF antenna one could put into a >backpack alogn with a QRP rig? It would be nice if the antenna could >be made to work on several bands. I've been thinking about the same thing recently. The system of choice might consist of a short dipole about forty or fifty feet long and a QRP link-coupled tuner. There have been a number of articles on tuners like this, and some were completely band-switched (no taps to change). A few also used toroidal inductors and were very small, exactly what's needed for backpacking. 73, Jack WB3U From lwbyppp@epix.net Thu Mar 21 13:41:55 1996 From: chideste@xvnews.unconfigured.domain (Dale Chidester) Newsgroups: rec.radio.amateur.antenna Subject: Re: Portable HF ant. suggestions? Date: 13 Mar 1996 20:17:31 GMT Message-ID: <4i7agr$h79@igate2.pt.cyanamid.com> References: <4i72co$mda@crash.microserve.net> Reply-To: chideste@xvnews.unconfigured.domain The best "portable" antenna I've found is a roll of wire, some nylon twine and a slingshot. Use a rock or heavy fishing weight and the slingshot to launch the nylon twine up into the highest tree you can find. Attach wire and pull it up. Use a small tuner to get a decent SWR and you're all set, on all bands! The longer the wire the better. 73, Dale From lwbyppp@epix.net Thu Mar 21 13:41:56 1996 From: Karl_Shepard@ccm.jf.intel.com (Karl Shepard) Newsgroups: rec.radio.amateur.antenna Subject: Put up a mast and need some antenna advice Date: Mon, 18 Mar 1996 09:18:08 Message-ID: This past weekend I put up a 30 foot mast. I have flag pole arrangement whereby I can put up and take down an inverted dipole quite easily. Currently, I am have a Radio Shack inverted V dipole antenna for shortwave that is supposed to be multiband (9 of 11 shortwave bands). It consists of 4 tuned lengths of wire on each side of the T-connector. The dipole is fed with 75 ft of 50 Ohm coax which in turn dumps into a Yaseu FRG 100. About 25-30 feet of the excess coax is coiled up and resides beneath the eave of the house. The legs of the inverted V are about 60 degrees apart. The ends of the antenna are a good 12--15 ft off the ground. Previously the antenna was run beneath the eaves of the house and was fed with about 12 feet of coax. It was about 8 feet off the ground and a section of it ran under the gutter about 8-10 inches away. To be quite honest, I have so far been unable to see a difference between the two setups. Granted, I have only listened for about one hour this morning - not a very good test - but the strength of the signals on the signal meter is the same. In the one day I have listened, I seem to hear more ham interferance than before but I can't really tell in one hour. I did get North Korea but then again I was looking for it. A salesman at Universial Radio said that the RS antenna is noisy. OK fine. What would be a better dipole for multi-band shortwave listening? I bought Joe Carr's Receiving Antenna book, but was disppointed that there was no recommendation of one antenna over another. Also, what angle for the legs is optimal for an inverted V dipole? What about a completely vertical mount? Would a horozontally mounted dipole with the antenna about 12-15 feet off the ground be as good or better than an inverted V? Another thing, I am having the darnedest time trying to understand what is meant by getting an antenna a quarter or half wave off the ground. It seems to me that a quarter or half wave off the ground could be a little or a lot depending on the wavelength - 120 meters to 11 meters in the case of shortwave . Ultimately, I would like to get African shortwave transmissions. I live on the west coast in Portland, Oregon. I know that I have asked a lot of questions but I do want to improve my reception. What is best for shortwave? Karl_Shepard@ccm.jf.intel.com From lwbyppp@epix.net Thu Mar 21 13:41:58 1996 Newsgroups: rec.radio.amateur.antenna From: n4lq@iglou.com (Steve Ellington) Subject: Re: Put up a mast and need some antenna advice Message-ID: References: Date: Mon, 18 Mar 1996 19:08:56 GMT You hit the nail on the head by this statement. Trying to get optimum reception from one antenna on vastly different wavelengths is not possible. I would require a seperate antenna for each sw band. Decide which frequency you want to monitor and build accordingly. Those megawatt stations are so strong that a few dbs isn't going to matter when it comes to configuring that RS antenna. : meant by getting an antenna a quarter or half wave off the ground. It seem s : to me that a quarter or half wave off the ground could be a little or a lot : depending on the wavelength - 120 meters to 11 meters in the case of shortwa ve. -- Steve Ellington N4LQ@IGLOU.COM Louisville, Ky From lwbyppp@epix.net Thu Mar 21 13:41:58 1996 From: Jay Newsgroups: rec.radio.amateur.antenna Subject: Question, where can I find ..... Date: Wed, 20 Mar 1996 07:56:03 -0500 Message-ID: <31500063.1BA4@fast.net> Can anyone suggest where I might be able to buy a piece of hardware used for anchoring guy wires call an "Earth Screw"? It kinda looks like an auger that can be turned into the ground with an eyeloop on the end for attaching guy wires to. Tnx in advance for any suggestions etc... Jay n2mga@fast.net From lwbyppp@epix.net Thu Mar 21 13:42:00 1996 From: Edward Lawrence Newsgroups: rec.radio.amateur.antenna Subject: Re: Question, where can I find ..... Date: 20 Mar 1996 20:45:35 GMT Message-ID: <4ipqpf$bf0@fcnews.fc.hp.com> References: <31500063.1BA4@fast.net> Try a mobile home supply. The anchors they use make fine guy wire anchors! From lwbyppp@epix.net Thu Mar 21 13:42:01 1996 From: "Anthony R. Gold" Newsgroups: rec.radio.amateur.antenna Subject: Re: QUESTION: RECV better than TXMT Date: Wed, 13 Mar 96 15:54:51 GMT Message-ID: <826732491snz@microvst.demon.co.uk> References: <4i1k2a$hhi@lambchop> <1996Mar12.191239.17604@ke4zv.atl.ga.us> <4i6iq8$g92@nadine.teleport.com> <4i6mih$lf7@crash.microserve.net> Reply-To: tgold@microvst.demon.co.uk In article <4i6mih$lf7@crash.microserve.net> jackl@pinetree.microserve.com "WB3U" writes: > I can't speak for Gary, but in my response to this I was thinking > about the distant signal also being refracted/reflected near its own > location. I suggest that all this non-reciprocal stuff is about 2 1/2 weeks early. Regards, -- Tony - G3SKR / AA2PM email: tgold@panix.com tgold@microvst.demon.co.uk packet: g3skr@n0ary.#nocal.ca.usa.na From lwbyppp@epix.net Thu Mar 21 13:42:03 1996 From: Zack Lau Newsgroups: rec.radio.amateur.antenna Subject: Re: QUESTION: RECV better than TXMT Date: Thu, 14 Mar 1996 12:40:27 -0500 Message-ID: <31485A0B.16A4@arrl.org> References: <4i1k2a$hhi@lambchop> <1996Mar12.191239.17604@ke4zv.atl.ga.us> To: Gary Coffman Gary Coffman wrote: > > In article <4i1k2a$hhi@lambchop> Ron Thompson wri tes: > >I have a unique situation that needs some help: > > > >I live in a valley, halfway up the hill on the north side. > >All the contacts I want to make are to the north of me, > >which is effectively blocked by the hill I live on. Across > >the valley is a big mountain that faces north. > > > >I have a 50 W 2M radio with a 4 Element Yagi Beam antenna > >with 10db gain. > > > >The beam is aimed south, directly towards the big mountain. > >I am effectively bouncing my signal off of it to get over > >the hill I am on. If I turned the beam around, it would > >would be pointed directly into the hillside. > > > >The problem is, my signal reception is much better than > >my signal going out. Tests I have done indicate that I > >can hear signals about 4 times farther away than I can > >with a 3db gain whip. The 3db whip puts out signals > >that can be heard about twice as far away than the beam > >though. A mobile unit 40 miles away transmitting on > >a simplex frequency can be heard clearly, but the mobile > >unit cannot hear my radio until it gets within 10 miles. > >Strange. > > > >Does anyone have any idea why this would happen? > > Sounds like you are under illuminating your reflector. > This is a common source of reduced gain with dish > antennas, and would also seem to apply in this case. > Try removing a director from your beam to widen its > main lobe. > > The reason the behavior appears non-reciprocal is > due to the fact that the mountain isn't a focusing > reflector, but rather is a scattering reflector due > to its rough surface. Thus on receive, where the > mountain is fully illuminated by the expanded wave > from the distant station, scatter is letting more > of the signal combine at your antenna than is the > case for the focused beam fed toward only part of > the mountain. Doesn't the beam have the same pattern on receive and transmit? I don't see what changes the scattering angles or efficency of energy transformation as you look at ray tracing examples and work it backwards. (the -20 dB angles of the antenna are the same for transmit and receive) My guess is that Ron's location is nicely shielded from noise sources, so Ron hears better than the mobile. Reception primarily depends on signal to noise ratio, as opposed to just the signal levels. Ron might outfit a mobile station with a very weak signal source to see if the noise level changes by driving all the way to Ron's location. I'd certainly like to know if this guess is proved wrong experimentally. This is why dishes hear better when slightly under-illuminated. While you are tossing away signal, you eliminate even more noise away more noise, so you come out ahead. Zack KH6CP/1 From lwbyppp@epix.net Thu Mar 21 13:42:04 1996 From: zeisu@snipe.dwe.co.KR (Jae-Soo Yoon) Newsgroups: rec.radio.amateur.antenna Subject: R7000+ Date: 15 Mar 96 06:30:44 GMT Message-ID: <9603140447.AA10820@snipe.dwe.co.kr> Has anybody had experiences with Cushcraft's new vertical R7000+? R7000 looks basically the same as R7 with some improvements. R7000+ is R7000 with optional 80M add-on. My current antenna covers 40-20-15-10 and I want to work on 80-30-17-12 in addition. R7000+ seems to be a good candidate if performance is good. Please any comments? 73 de Jae-Soo DS1DOA From lwbyppp@epix.net Thu Mar 21 13:42:05 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: RFI with stereo: need filter advice/RFI from AM xmtr, what to do? Date: Sun, 17 Mar 96 15:43:22 GMT Message-ID: <4ihc7u$pvl@crash.microserve.net> References: bb840@scn.org (James Aeschliman) wrote: >I believe I read in a recent QST not to put by-pass capacitors on >speakers connected to a solid state amplifier, because they may >cause a runaway situation and burn up the amplifier. I could be >wrong or not remembering correctly, but I suggest checking it out >first. Apparently solid state is real touchy. The output impedance of solid state amps is something on the order of a few tenths or even a few hundredths of an ohm. At 20 KHz, the reactance of a 0.01 uF capacitor is approximately 800 ohms, and a 0.001 uF is nearly 8,000 ohms. This is almost insignificant in comparison to both the impedance of the amplifier and the parallel capacitance presented by the crossover network in most speakers. 73, Jack WB3U From lwbyppp@epix.net Thu Mar 21 13:42:06 1996 From: Scott Ellington Newsgroups: rec.radio.amateur.antenna Subject: Re: RFI with stereo: need filter advice/RFI from AM xmtr, what to do? Date: Tue, 19 Mar 1996 12:01:20 -0600 Message-ID: <314EF670.7BDC@ssec.wisc.edu> References: <4iaas7$39l@crash.microserve.net> Reply-To: sellington@ssec.wisc.edu In case of RFI getting in through the speaker leads, it may be necessary to add more common-mode impedance than you can get with a few turns around a split core. One solution that has worked for me is making a common-mode choke with bifilar magnet wire wound on a ferrite toroid. AWG 20 wire should be adequate, with 10-20 turns on a toroid or bead perhaps 3/4 inch in diameter. Scott K9MA sellington@ssec.wisc.edu From lwbyppp@epix.net Thu Mar 21 13:42:07 1996 Newsgroups: rec.radio.amateur.antenna From: psoper@encore.com (Pete Soper) Subject: RFI with stereo: need filter advice/RFI from AM xmtr, what to do? Date: Thu, 14 Mar 1996 21:54:14 GMT Message-ID: My amateur signals come out of my home stereo receiver. I've done the experiments to confirm that this is due to pickup by the (long) speaker wires running under the floor to the receiver's speaker connectors. Wrapping the speaker wires around seven ferrite cores didn't result in any attenuation so I assume I've got a differential and not a common mode path. I'm considering building low pass filters for each of the five speaker outputs but before I build and test the first one I thought I'd check with the collective wisdom of those readers who have "been there, done that". My first cut would be a series inductor of perhaps 20 microhenries and a small cap of perhaps .01ufd to ground (numbers from memory). The goal would be to start rolling off at around a hundred khz to a half megahertz or thereabouts. If I got 15-20db attenuation at 7mhz my problem would be solved. Adding a second cap would be better for me than going with a larger L to move the cutoff down. Would an LC filter like this constitute a capacitive load (with its potential for making the amplifier unstable)? I'm concerned about Ed Hare's warning in the Antenna book but can't understand the distinction between his admonishment against putting a cap across the speaker outputs vs having caps from each output leg to ground (and isn't one leg likely to be at ground?). Any other comments or ideas? My second situation is that the AM "advert" broadcasts from a little transmitter at the model home of a new development near me is nailing the 17 meter band. The signal level is around S3 (Silly level #3) which is within just a few S units of the fundamental! This from what surely must be just a few milliwatts roughly 100 yards from my house. The fundamental is at 1610 khz. Thus the crud I get appears to be the 11th harmonic plus my third IF frequency (i.e. 1.610 * 11 + .455 = 18.160). Is the solution likely to be on my end (i.e. I need to a high pass filter to attenuate the BC frequency) or on the xmit end? If on the xmit end, would I be in my rights to insist that they get a transmitter that doesn't put out so much energy out of band? Is it possible this unit they are using would come under Part 15 and thus fall under the "must not cause interference" clause of that reg? On the one hand, if I could get them to just tweak the frequency up or down the slightest bit they'd jump out of the 17m band. On the other hand I spent an entire summer with the county commisioners fighting against this (high density in the country) development, so they may not like me anymore. :-( Any help in this area would be appreciated. Regards, Pete KS4XG (central North Carolina, USA) From lwbyppp@epix.net Thu Mar 21 13:42:09 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: RFI with stereo: need filter advice/RFI from AM xmtr, what to do? Date: Thu, 14 Mar 96 23:37:32 GMT Message-ID: <4iaas7$39l@crash.microserve.net> References: psoper@encore.com (Pete Soper) wrote: >My amateur signals come out of my home stereo receiver. >I've done the experiments to confirm that this is due to >pickup by the (long) speaker wires running under the floor >to the receiver's speaker connectors. Wrapping the speaker >wires around seven ferrite cores didn't result in any >attenuation so I assume I've got a differential and not a >common mode path. In my experience, that would be *very* unusual, particularly on lower HF frequencies. You could verify it by placing toroids over the individual wires, though. What kind of toroids did you use, how long are the wires and what frequency were you operating on? Also, what power level are you using, and how is the transmit antenna system driven and configured? Are other appliances picking up the interference? Have you tried additional toroids on the AC line cord to the stereo receiver? Is the interference present if you disconnect the speaker cables and use headphones (or was this how you proved it was the speaker cables)? >Would an LC filter like this constitute a capacitive load (with >its potential for making the amplifier unstable)? I'm concerned >about Ed Hare's warning in the Antenna book but can't understand >the distinction between his admonishment against putting a >cap across the speaker outputs vs having caps from each output >leg to ground (and isn't one leg likely to be at ground?). I've used filters like that in the past, but they were never very effective because the problem was mostly common-mode. Yes, one speaker terminal is usually at chassis ground, although that may not always be true. I don't have the book you're referring to, but I don't see the difference either. At the frequencies an amplifier might oscillate at, I wouldn't think the location of the cap would make much difference. The inductance of speaker wires is not usually a consideration. At any rate, unless your receiver is overly susceptible, small amounts of capacitance like you're describing shouldn't cause a problem. Most speaker crossover networks place quite a bit of capacitance across the output of the amplifiers. Consider a tweeter connected in series with an electrolytic capacitor, both placed across the output. At low frequencies, the low reactance of the tweeter's voice coil will place quite a bit of signal across the capacitor, but the amplifier doesn't osillate. Compared to L/C crossover networks, .001 or .01 caps are practically invisible. >My second situation is that the AM "advert" broadcasts from a >little transmitter at the model home of a new development near >me is nailing the 17 meter band. I'd like to hear more about your antenna system. This might be the fault of the remote transmitter, but it could also be related to the RFI problem. 73, Jack WB3U From lwbyppp@epix.net Thu Mar 21 13:42:10 1996 From: Bix Morgan Newsgroups: rec.radio.amateur.antenna Subject: Roof Safety Date: Fri, 15 Mar 1996 12:40:38 +0000 Message-ID: <31496546.58AB@persoft.com> Now that the weather is getting warmer I'm starting to think about finally installing an antenna on the roof (2 meter beam). I'm wondering whether any of the old pros have any suggestions about working safely on a roof. My particular roof is quite steeply pitched (more than 45 degrees) and the apex is a good 30 feet from the ground. It's a fairly new construction and there really isn't anything to anchor myself to (no chimney). If anyone has any tips that might keep me from taking a spill I'd sure appreciate hearing them. Thanks. Bix Morgan (KG9AZ) bix@persoft.com From lwbyppp@epix.net Thu Mar 21 13:42:11 1996 Newsgroups: rec.radio.amateur.antenna From: gary@ke4zv.atl.ga.us (Gary Coffman) Subject: Re: Roof Safety Message-ID: <1996Mar17.193651.12513@ke4zv.atl.ga.us> Reply-To: gary@ke4zv.atl.ga.us (Gary Coffman) References: <31496546.58AB@persoft.com> Date: Sun, 17 Mar 1996 19:36:51 GMT >Bix Morgan wrote: > >Now that the weather is getting warmer I'm starting to think >about finally installing an antenna on the roof (2 meter beam). >I'm wondering whether any of the old pros have any suggestions >about working safely on a roof. My particular roof is quite >steeply pitched (more than 45 degrees) and the apex is a good 30 >feet from the ground. It's a fairly new construction and there >really isn't anything to anchor myself to (no chimney). If >anyone has any tips that might keep me from taking a spill I'd >sure appreciate hearing them. Thanks. There are several tricks to working on a steeply pitched roof. One common roofer trick is to use "chicken ladders". This is simply a long plank with cross pieces nailed to it forming steps. At one end, you nail a piece that will hook over the peak of the roof. You can then use the chicken ladder steps to give you a purchase as you move up and down the pitch. Another method is to clamp long boards horizontally across the roof pitch. This again gives you a point of purchase, but now for moving back and forth across the face of the pitch. Regardless of whether you use either of these types of improvised scaffolding, you should wear a rappelling harness and have a rope run over the pitch of the roof and anchored securely to something on the ground on the other side of the house. You can use a car bumper, but if you do, make sure you have *all* of the keys to that car in your pocket first. It wouldn't do to have a member of the family hop in the car and drive away. Don't try to use the car to pull you up and down the roof, the coordination and control required simply isn't there, and there's a good chance you'll be hurt. Gary -- Gary Coffman KE4ZV | You make it, | Due to provider problems Destructive Testing Systems | we break it. | with previous uucp address es 534 Shannon Way | Guaranteed! | Email to ke4zv@radio.org Lawrenceville, GA 30244 | | From lwbyppp@epix.net Thu Mar 21 13:42:13 1996 From: "Mark G. Wiltrakis" Newsgroups: rec.radio.amateur.antenna Subject: Rotator-mast pinning advice Date: 17 Mar 1996 20:03:42 GMT Message-ID: <4ihr6u$70s@nadine.teleport.com> I live in a very wind-prone QTH and have heavy antennas (5 el 20m, 7 el 15m monobanders) up at 100 feet.Today's nice wx allowed me to inspect my rotator (Create model RC5B-3) which has been nonfunctional since a huge December windstorm. The two mast clamps had partially disintegrated (3 by 2 cm. holes) at the tow points where I had drilled them and "pinned" the mast with a 1/4 inch bolt. Any suggestions: 1. How large a bolt diameter is optimum for pinning? 2. Any other tricks to solidify mast to mast clamp connections? All advice welcomed!! Thanks and 73, Mark, N7MMQ Hillsboro, OR trackus@teleport.com From lwbyppp@epix.net Thu Mar 21 13:42:14 1996 From: "Ian White, G3SEK" Newsgroups: rec.radio.amateur.antenna Subject: Re: RSGB info. Date: Sat, 16 Mar 1996 21:17:43 +0000 Distribution: world Message-ID: References: <261akcs60.alamito@banana.speed.satlink.net> Anibal Aguirre wrote: >hi:i`d like to buy the rsgb vhf\uhf manual and the rsgb microwaves book. >i tried to communiacte with rsgb by e-mail (rsgb@feedback.org) but i never >received reply. >does anybody know the correct RSGB`s e-mail for this purpose??? Sorry, RSGB headquarters does not have e-mail. The address rsgb@feedback.org is only for the Web pages which are being run by outside volunteers. RSGB headquarters hopes to have e-mail later this year. For now, you can only order books by phone, fax or mail. RSGB accept all major credit cards. Their phone number is +44 1707 659015, although fax is obviously cheaper and more accurate: +44 1707 645105. The mailing address is: RSGB Lambda House Cranborne Road POTTERS BAR EN6 3JE England 73 from Ian G3SEK Editor, 'The VHF/UHF DX Book' 'In Practice' columnist for RadCom (RSGB) Professionally: IFW Technical Services Clear technical English - anywhere. From lwbyppp@epix.net Thu Mar 21 13:42:15 1996 From: pdema20315@aol.com (PDema20315) Newsgroups: rec.radio.amateur.antenna Subject: secret service freqs. Date: 16 Mar 1996 17:09:49 -0500 Message-ID: <4ife7d$h4t@newsbf02.news.aol.com> Reply-To: pdema20315@aol.com (PDema20315) www. address for secret service freqs and code names From lwbyppp@epix.net Thu Mar 21 13:42:16 1996 From: w8jitom@aol.com (W8JI Tom) Newsgroups: rec.radio.amateur.antenna Subject: Re: Shielded Coax Pair Dipole Feed Date: 12 Mar 1996 16:11:52 -0500 Message-ID: <4i4pao$pei@newsbf02.news.aol.com> References: <4i3799$c5j@crash.microserve.net> In a message dated 96-03-12 15:21:06 EST, you write: >Huh? Splitting power among a number of matched lines all with the same >matched loss results in total loss equal to any one of the lines. That >assumes you loose nothing in the splitting... Yeah Tom, and I knew better from the parallel coax thread. What was I ever thinking? Oh, I know! I was thinking the coax carried constant current and the path through the other small conductor was much lossier than the path through the shield. I overcomplicated a simple problem! That's usually trouble ;-) So the loss would be the SAME as in a single coaxial line with the same SWR. OK, the question remains the same. Why use it? 73 Tom From lwbyppp@epix.net Thu Mar 21 13:42:17 1996 From: rheiss@tuba.aix.calpoly.edu (Robert Everitt Heiss) Newsgroups: rec.radio.amateur.antenna Subject: Re: Shielded Coax Pair Dipole Feed Date: 14 Mar 1996 00:00:29 -0800 Message-ID: <4i8jmt$2c4t@tuba.aix.calpoly.edu> References: <4i2mk1$8a3@news.pacifier.com> In article <4i2mk1$8a3@news.pacifier.com>, Ron Ries wrote: >When using a pair of coax to feed a dipole, i.e., using the center >conductors in each coax as a differential feeder (also using a 4:1 >balun), does one gain the advantage of half the lossiness of a single >coax in a non-resonant configuration and twice the resistance to >breakdown with SWR of greater than 5? The example is called the "Spencer" Yes, I believe it has the advantages claimed. Using higher impedance coax such as RG62 (almost 100 ohms) instead of 50 ohm would further decrease the loss, by improving the match on 20 at the antenna feedpoint. But then you have a 50 ohm line before the balun, and 4*50=200 ohm line after it, so moving the balun up to the feedpoint would not change the SWR or losses in the coax. If the balun is a current-type or you add a bead balun on the single 50 ohm coax near the feed point, you can then drastically reduce the SWR and losses on both bands by moving the feed off center. I think that would be what Antennas West calls a TNT/2 windom. 73, Rob KO6KA rheiss@tuba.calpoly.edu From lwbyppp@epix.net Thu Mar 21 13:42:18 1996 From: Zack Lau Newsgroups: rec.radio.amateur.antenna Subject: Re: Shielded Coax Pair Dipole Feed Date: Wed, 13 Mar 1996 12:50:32 -0500 Message-ID: <31470AE8.48D3@arrl.org> References: <4i3799$c5j@crash.microserve.net> <4i3v0t$h5u@newsbf02.news.aol.com> W8JI Tom wrote: > > Hi Ron, > rvr@pacifier.com (Ron Ries) wrote: > > > >When using a pair of coax to feed a dipole, i.e., using the center > >conductors in each coax as a differential feeder (also using a 4:1 > >balun), > > OK, that doubles the loss when the system is matched in both cases. Measurements and computer simulations I've done seem to indicate little difference in loss with matched transmission lines, assuming you accurately match the electrical lengths. Zack KH6CP/1 From lwbyppp@epix.net Thu Mar 21 13:42:19 1996 From: w5gyj@primenet.com (James E. Bromley) Newsgroups: rec.radio.amateur.antenna Subject: Re: Strange Phenonomon on G5RV Date: 12 Mar 1996 13:58:00 -0700 Message-ID: References: <4h3433$2nb@news.fwi.com> <4h5rlh$cs8@news.one.net> <4hhune$21q@news.aros.net> <4hmq1n$nqk@crash.microserve.net> PHIL DIAZ,kc7afb writes: > i first saw this arcing about 2 years ago on a 10 meter vertical and >have witnessed it many times, particularly through some windy snow >storms... > you can usually hear it coming on an hf rig, like when you hear the >static of a thunderstorm and lightning in the distance. The explanations of static charge buildup and atmospheric discharge concerning this connector arcing problem go a long way. I would like to add one other - Electromagnetic Pulse (EMP). I observed such arcing across the connector of a disconnected 40-meter dipole strung at a slant to the 100-foot level of 370-foot tower on top of a mountain near El Paso, Texas. Every time I observed a lightning strike in the city, I would immediately hear a snap across the connector. I surmised that this was due to the high-intensity, broad-band radio wave radiated by the lightning discharge being received by the elevated antenna. EMP is usually associated with nuclear detonations in the upper atmosphere, but nearby lightning can produce field strengths that are comparable - something in the 5 kV/m to 50 kV/m range. Just another hazard of the hobby I suppose, but one to look out for. Jim, W5GYJ Glendale, AZ From lwbyppp@epix.net Thu Mar 21 13:42:21 1996 From: rikoski@niia.net (Rick Rikoski) Newsgroups: rec.radio.amateur.antenna Subject: Sturba Curtain Date: Mon, 18 Mar 1996 07:32:58 -0500 Message-ID: I'm fascinated with the idea of building a couple of Sturba curtains for UHF and also VHF (2 separate antennas) tv reception. Can they be made broadband enough? Suggested design dimensions? General comments? For you old timers: wasn't there a 4 stack antenna sold and quite popular in the "50's in the US for VHF tv that looked like a Sturba? Help me out here. Was it a Sturba? Anybody remember details? -- Rick Rikoski Chicago/Indiana Dunes rikoski@niia.net From lwbyppp@epix.net Thu Mar 21 13:42:22 1996 From: VE4KLM Newsgroups: rec.radio.amateur.antenna Subject: Re: Sturba Curtain Date: Thu, 21 Mar 1996 09:36:24 -0600 Message-ID: References: On Mon, 18 Mar 1996, Rick Rikoski wrote: > I'm fascinated with the idea of building a couple of Sturba curtains for > UHF and also VHF (2 separate antennas) tv reception. > > Can they be made broadband enough? Suggested design dimensions? General > comments? Hello Rick, you have definitely perked my interest since I just finished building a 4 element sterba array (curtain) for 2 meters. My curtain is centered at 146 MHz, and fed with (believe it or not) plain 300 ohm tv twin lead that is matched to my hand held through a home made 2 meter transmatch. The array is vertically oriented since most of the 2 meter stuff around here is vertically polarized. I'll have to dig around at home for the details, since I am currently at work. I will see if I can post them for you within several days. I can not give you a reasonable performance spec since I really have nothing to compare the sterba to, except for a vertical 1/2 wave dipole that sits about 10 feet higher than the array. The 1/2 wave is fed with RG/58, which is not very good at VHF frequencies, considering that the run is over 40 ft. The sterba does get out better, and is better at picking up weak signals. It is an extremely quite antenna (no difference in rcvr noise before and after plugging in the antenna). For some other reason I no longer get the intermod that has plagued me when I was using the 1/2 wave. That I like !!! Keep in mind the sterba is bidirectional, NOT omnidirectional. For tv purposes , the curtain would be horizontally oriented (which it usually is anyway), so I do not see why it would not work. Bandwith : For transmission SWR considerations, I found the bandwith limited to about 1 Mhz (.5 Mhz on either side of the 146 center frequency). That consideration includes the use of the transmatch to keep SWR down. I could possibly do better had I built a better transmatch. Regards, Maiko Langelaar VE4KLM --------------------- | SLM Software Inc. | | slmusr03@SLMSoft.CA | --------------------- From lwbyppp@epix.net Thu Mar 21 13:42:23 1996 From: wb2kfo@i-2000.com (Harry) Newsgroups: rec.radio.amateur.antenna Subject: Re: Ten Tec and Equipment for sale Date: 15 Mar 1996 02:32:18 GMT Message-ID: <4iakri$fpm@i-2000.com> References: <4hr2l3$hcq@i-2000.com> Thank you for the response. The swr analyzer is sold. From lwbyppp@epix.net Thu Mar 21 13:42:23 1996 From: Jeff Newsgroups: rec.radio.amateur.antenna Subject: test ,don`t read Date: 16 Mar 1996 18:42:31 GMT Distribution: world Message-ID: <4if22n$2f8@atlas.uniserve.com> test From lwbyppp@epix.net Thu Mar 21 13:42:24 1996 From: Marty Gulseth Newsgroups: rec.radio.amateur.antenna Subject: test post - pls ignore Date: 20 Mar 1996 20:42:42 GMT Message-ID: <4ipqk2$j4e@hpcvsnz.cv.hp.com> this is a test. From lwbyppp@epix.net Thu Mar 21 13:42:25 1996 From: Cecil Moore Newsgroups: rec.radio.amateur.antenna Subject: Tunable tunerless G5RV Date: 13 Mar 1996 17:49:45 GMT Distribution: world Message-ID: <4i71rp$mqn@chnews.ch.intel.com> Here's an off-the-wall idea that really works. Discount auto parts stores carry replacement telescoping radio antennas. I bought 4 for about $5 each. They are adjustable from 2 ft to 5 ft. I mounted a pair end-to-end to get an adjustment range of 4 ft to 10 ft. and installed 1/4 in spacers between the two devices to get a 4 ft to 10 ft adjustable series transmission line section. That is all the adjustment needed on my G5RV to resonate every band except 30m and 30m is even a lot better with 24 ft of series ladder-line. The thing could even be automated with a small garage door opener. Adjusting the series section for minimum SWR results in feeding the system at a current node which, on my antenna, results in a 50 ohm SWR of less than 2:1. By being infinitely adjustable, it covers entire bands. The impedance bumps at the different sizes of telescoping sections don't seem to bother the operation. Copper or aluminum tubing would work just as well, maybe better. 73, Cecil, KG7BK, OOTC (not speaking for my employer) From lwbyppp@epix.net Thu Mar 21 13:42:26 1996 From: Cecil Moore Newsgroups: rec.radio.amateur.antenna Subject: Re: Tunable tunerless G5RV Date: 15 Mar 1996 19:04:40 GMT Distribution: world Message-ID: <4icf08$ve4@chnews.ch.intel.com> References: <4i71rp$mqn@chnews.ch.intel.com> <4i7foe$nn9@crash.microserve.net> jackl@pinetree.microserve.com (WB3U) wrote: Thanks Jack, for the suggestions. Further thought on the tunable G5RV has lead to the following: Assuming an Inverted-V or center support for a horizontal, seems the most logical configuration would be two 18 ft. runs of copper tubing down the pole, stood off if necessary. Then 16 ft. of large solid copper wire that slides into the copper tubing. The 18 ft. minimum is needed for 30m and the 34 ft maximum is needed for 17m at my QTH. This should give a continually adjustable perfectly tuned G5RV for all HF bands *and* sub-bands. If one can stand 130 ft. of ladder-line, the tuning device can be located near the operating position. 73, Cecil, KG7BK, OOTC (not speaking for my employer) From lwbyppp@epix.net Thu Mar 21 13:42:27 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: Tunable tunerless G5RV Date: Wed, 13 Mar 96 21:42:34 GMT Message-ID: <4i7foe$nn9@crash.microserve.net> References: <4i71rp$mqn@chnews.ch.intel.com> Cecil Moore wrote: >Here's an off-the-wall idea that really works. Discount auto parts >stores carry replacement telescoping radio antennas. I bought 4 for >about $5 each. They are adjustable from 2 ft to 5 ft. I mounted a >pair end-to-end to get an adjustment range of 4 ft to 10 ft. and >installed 1/4 in spacers between the two devices to get a 4 ft to >10 ft adjustable series transmission line section. That is all the >adjustment needed on my G5RV to resonate every band except 30m and >30m is even a lot better with 24 ft of series ladder-line. This sounds like the Invention Of The Month! You've just won some more free advice on your 5-position tuner switch. ;) I think you said something awhile back about preferring to use a Pi network configuration whenever possible. With that in mind, I came up with the following: Position 1: Balanced T-netork Position 2: Balanced Pi-network Position 3: Add additional fixed inductance to the balanced Pi Position 4: Add additional fixed capacitance at the output of the Pi Position 5: Move the capacitance added in Position 4 to the input The only thing I'm not sure of is whether this is the correct order to add the additional components. For instance, maybe it would be better to be able to switch in the caps without the additional inductance, in which case Position 3 above should actually be Position 5. Also, considering that the rollers are effectively in series in the balanced Pi configuration, you may have plenty of inductance as-is. In that case, it would be better as follows: Position 3: Add a fixed capacitor at the output of the Pi Position 4: Remove the output capacitor and add a cap at the input Position 5: Add the additional capacitance at both input and output The reason for not using Position 5 alone is that the minimum capacitance in that position might restrict the tuning range, even on the lower bands. Anyway, the general idea is to extend the range of the balanced Pi on 80M and 160M. Then you'll have the choice of using either a Pi or T network on any band from 160-10M, and the decision won't have to based so much on the limitations of the tuner. 73, Jack WB3U From lwbyppp@epix.net Thu Mar 21 13:42:29 1996 From: rikoski@niia.net (Rick Rikoski) Newsgroups: rec.radio.amateur.antenna Subject: Re: Vhf, Uhf Log Periodic?? Date: Tue, 19 Mar 1996 09:30:27 -0500 Message-ID: References: <4ijiqu$lp6@news1.sunbelt.net> In article <4ijiqu$lp6@news1.sunbelt.net>, KI4TZ@sunbelt.net (Joe Barkley) wrote: > Someone mentioned to me there is a 6meter-1.2ghz log periodic on the market. > Anyone know of it or had experience with it. I am just getting on 6 meters a nd > want a decent directional antenna and only have roomfor one yagi an top of A -4 > hf yagi. Any comments or suggestions would be helpful. > >================ Joe, there is one. It is called the "Create" It think it is made in Virginia, the land of the CIA. Costs $300 or $400 bucks. I understand that it has the gain and rejection qualities of a 4 element yagi-uda on any frequency in this range. Pretty small too. I'd be interested in buying one, if I could get a good price. -- Rick Rikoski Chicago/Indiana Dunes rikoski@niia.net From lwbyppp@epix.net Thu Mar 21 13:42:30 1996 Newsgroups: rec.radio.amateur.antenna From: dstock@hpqmdla.sqf.hp.com (David Stockton) Subject: Re: Vhf, Uhf Log Periodic?? Message-ID: Date: Thu, 21 Mar 1996 13:24:59 GMT References: <4ijiqu$lp6@news1.sunbelt.net> Joe Barkley (KI4TZ@sunbelt.net) wrote: : Someone mentioned to me there is a 6meter-1.2ghz log periodic on the market. : Anyone know of it or had experience with it. I am just getting on 6 meters a nd : want a decent directional antenna and only have roomfor one yagi an top of A -4 : hf yagi. Any comments or suggestions would be helpful. Log periodics are specialised antennae optimised for uniform operation over a wide band at all costs. There is not one design but a family. How many elements are used *per octave of coverage* sets their gain. Their gain and VSWR ripple over frequency range, more elements for the same range gives smaller gain and VSWR ripples. At any spot freq you only have a few elements "on song", the rest do nothing. You will be sticking plenty of metal in the air that is only used to give coverage of frequencies *between*, the amateur bands. A small yagi for each of the amateur bands can easily give more gain per pound of metal. If you want a directional RX antenna to listen to everything in the 50-1300 MHzrange, then a Log-Periodic will be great. For some reason, L-P's have become fashionable, their specialisation and compromises being eith er not mentioned or ignored. Sorry for the bad news, David From lwbyppp@epix.net Thu Mar 21 13:42:30 1996 From: w7el@teleport.com (Roy Lewallen) Newsgroups: rec.radio.amateur.antenna Subject: Re: W6KKT VISALIA HF MOBILE ANTENNA "SHOOTOUT" INFO Date: Wed, 13 Mar 96 13:03:23 GMT Message-ID: <4i6h12$g92@nadine.teleport.com> References: <4hc0ac$leq@ns.kern.com> <4hhego$8np@newsbf02.news.aol.com> <4i4ltr$f2d@crash.microserve.net> How far is this event from the main convention? I'm giving a talk from 9 - 10 a.m. and the "shootout" begins at 10. Hope I have a chance to watch it. Roy Lewallen, W7EL From lwbyppp@epix.net Thu Mar 21 13:42:32 1996 Newsgroups: rec.radio.amateur.antenna From: bart@wb6hqk.ampr.org (Bart Rowlett) Subject: Re: W6KKT VISALIA HF MOBILE ANTENNA "SHOOTOUT" INFO Message-ID: References: <4hc0ac$leq@ns.kern.com> <4i4ltr$f2d@crash.microserve.net> Date: Wed, 13 Mar 1996 16:16:47 GMT In article <4i4ltr$f2d@crash.microserve.net>, WB3U wrote: > Cecil Moore wrote: >>Bart Rowlett writes: >> >>>the near field remaining at the test distance. Since the antenna >>>heights are all about the same (13.5 feet maximum), it is assumed >>>the near field >> >>Is there any limit on length of the antenna as long as the 13.5 ft >>height limit is observed? Could the antenna, for instance, be a 40 ft >>loop from front bumper to rear bumper as long as it didn't get above >>13.5 ft in height? > >How about the diameter of the mast? Would it be permissable to be, >say, slightly larger that the diameter of a 3-500Z? I've heard large >masts like that often result in much greater field strength, although >no one's sure exactly why. ;) Large diameter masts increase the capacitance of the top part which reduces the required loading inductance and it's associated losses. Reduced reactance also decreases the Q and widens the bandwidth. However, it's best to minimize capacitance near the coil since it's effect is to increase reactive circulating currents in the coil. The classical top hat at the very top of the radiating mast is usually optimum if you can tolerate such a 'branchcatcher'. > >Cecil, if you'll bring a loop, I'll bring two of my "super efficient" >masts to support it. Say, what's the prize for winning this shootout? According to W6KKT, fame, glory and bragging rights :-) bart wb6hqk bart@wb6hqk.ampr.org From lwbyppp@epix.net Thu Mar 21 13:42:33 1996 From: Edward Lawrence Newsgroups: rec.radio.amateur.antenna Subject: WANTED: HP 8753 Network Analyzer Date: 19 Mar 1996 15:15:06 GMT Message-ID: <4imj1q$4dp@fcnews.fc.hp.com> I would like to buy an HP 8753 Network Analyzer with a HP 86046 S-Parameter test set, if I can find one at less than the National Debt. Any one have one at a reasonable price? Please respond by email to eal@hpeseal.fc.hp.com TNX WA5SWD From lwbyppp@epix.net Thu Mar 21 13:42:34 1996 From: stubstad@ix.netcom.com(S) Newsgroups: alt.radio.scanner,alt.radio.pirate,aus.radio,rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc,rec.radio.scanner,rec.radio.shortwave,uk.radio.amateur Subject: Re: Weird Radio Problem Date: 17 Mar 1996 00:54:20 GMT Message-ID: <4ifnrs$aol@dfw-ixnews3.ix.netcom.com> References: In petern@terraport.net (Peter Neidhardt) writes: I intermittenly pickup actual radio >transmissions from overhead commercial airliners. Does anyone have any idea what causes this? I thought >Commerical Airline bands were totally different and not even close to the >FM bands. You are receiving civilian air comms on the image frequency of your FM RX. The civ air band is 108-136 MHz. Your FM RX tunes 88-108 and probably uses a LO at (88->108)+ 10.7 MHz to convert down to an IF at approximately 10.7 MHz. This means that strong air signals at approximately 2*10.7=21.4 MHz above the tuned FM band frequency will come in. Your radio is an FM RX, the air comms are AM, so audio may be distorted or noisy. Example...if a local tower uses say 120.1 MHz, you might hear it at about 98.7. Jim From lwbyppp@epix.net Thu Mar 21 13:42:36 1996 From: jlundgre@delta1.deltanet.com (John Lundgren) Newsgroups: alt.radio.scanner,alt.radio.pirate,aus.radio,rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc,rec.radio.scanner,rec.radio.shortwave,uk.radio.amateur Subject: Re: Weird Radio Problem Date: 19 Mar 1996 01:03:11 GMT Message-ID: <4il14f$1jj@news02.deltanet.com> References: <4iisa8$638@kaiwan.kaiwan.com> I don't think there is any point in trying to make a silk purse out of a sow's ear. He should go get a decent radio receiver rather than try to patch up a poor one. Also, it may help more to decrease the signal strength rather than increase it. Anthony O. Cardenas ~ WA6IGJ (cardenas@kaiwan.com) penned: : petern@terraport.net (Peter Neidhardt) wrote: : >I own a cheap General Electric boombox... I am on a certain FM channel : > I intermittenly pickup actual radio transmissions from overhead commercial : >airliners... : ^^^^^^^^^^^^^^^^^^^^^^snip -to-fit^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ : Paul, : The aircraft band is right next door to broadcast fm music band. ADD your : fm receiver's 'IF'- frequency (some times 20.x MHz or 10.xMHz) and with a : strong enough signal from a aircraft right overhead, you may get a "mix". : Your aircraft can 'mix' with your desired station +'IF' and there you : have it. Often even more magic is involved... where two signals transmitt : at the same time and mix down to your fm receiver. Infact there is a very : obscure program (no I don't have it) that calculates where the offending : signals are and next is to build a filter to trap out at least one of the : offenders. : The cure? Add a external FM Antenna... the better fm antennas look much : like a TV Antenna, except the elements are almost all the same length... : Use 300 ohm 'twin-line' to feed the signal to the set. Twist the : twin-line as it passes from antenna, all the way to the set. : What? No screw terminals for the two wires? Then try a random 'long : wire' antenna with a alligator clip on the business end and clip it to : your whip antenna! You may need to move the long wire around till you find : the best signal. This should provide a stronger signal from you FM station : and hopefully swamp the front-end with 'desired' signal. : Weinguard makes a FM PASS filter (75 ohm coax 'f' fittings)... this signal : loves the FM Brodcast band and tries it's best to reject other signals : above and below the band. Cost, about $12, retail. I can't vouch for the : quality of a Radio Shack equiv. More elabroate 'tunable' 'notch' filters : can be had, but for lot's more money for one of quality. : Hope this helps! : Tony : WA6IGJ -- #======P=G=P==k=e=y==a=v=a=i=l=a=b=l=e==u=p=o=n==r=e=q=u=e=s=t======# | John Lundgren - Elec Tech - Info Tech Svcs. | jlundgre@ | | Rancho Santiago Community College District | deltanet.com | | 17th St at Bristol \ Santa Ana, CA 92706 | http://rsc.rancho| | My opinions are my own, and not my employer's. | .cc.ca.us | | Most FAQs are available through Thomas Fine's WWW FAQ archive: | |http://www.cis.ohio-state.edu:80/hypertext/faq/usenet/FAQ-List.html| | "You can flame your brains out -- it won't take long." | #===T=u=z=l=a==C=o=m=p=a=n=y=.=.===t=h=r=e=e='=s==L=e==C=r=o=w=d=!==# From lwbyppp@epix.net Thu Mar 21 13:42:38 1996 Newsgroups: alt.radio.scanner,rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc,rec.radio.scanner,rec.radio.shortwave From: grohe@galaxy.nsc.com (Paul Grohe) Subject: Re: Weird Radio Problem Message-ID: <314e712d.11687875@139.187.128.43> Reply-To: grohe@galaxy.nsc.com References: <4idjm1$f0c@madeline.INS.CWRU.Edu> <314D9822.371D@vertex.ucls.uchicago.edu> Date: Tue, 19 Mar 1996 09:52:05 GMT Whoa guys! We all agree that it is an image. That's a given! But putting a bigger antenna on it won't help! If you were standing next to a jet engine, would you cup your ears to hear it better? Or would you cover your ears? If it *is* causing non-linearities in the front-end, overloading it even more is not going to help (why do you think they put the -20dB switch on good receivers?). Try *collapsing* the antenna, or move it around. I know it sounds strange, but it does work. I lived directly under the path of SFO's main runway for 20 years and I have experienced almost every type of interference from airplanes. Cheap radios always received them. With high quality receivers, you usually would hear a slight drop in audio level. Like the noise, you just have to live with it. Cheap RFI filters simply don't work. The tuners front end contains the resonant circuit which is supposed to favor the intended signal (101.7) and reject the un-intended ones (123.1). In cheap radios, this circuit is not very good, so the rejection (selectivity) goes to pieces. The quality of the IF stages also has a lot to do with it. If the radio has a image rejection of 20dB, that means that the airplane signal has to be at least 100 times more powerful than the FM station to "break through". Easy to do when the airplane is right above your head and the FM station is 10 miles away! Capture ratio sez it only takes a dB or two to override the intended signal. And it does it! Your best bet is to try another radio. Some *are* better than others. On Mon, 18 Mar 1996 11:06:42 -0600, in newsgroup rec.radio.scanner, Isaac Kohn from Ripco Communications, Inc. thoughtfully posted: >There is a small, minor detail: Air transmissions were AM, last time I > checked! They still are! >How does an FM receiver with poor-selectivity receive AM > transmissions??? FM detectors are capable of detecting AM signals through "Slope Detection". In a nutshell: If you tune a FM detector off to one side, you can detect AM. When a FM detector is tuned "dead-on", it will have the most AM rejection. When it is tuned off resonance, to where the signal is now riding up-and-down on the steeper outer slopes of the detector curve, you create an AM detector (the detector curve is "bell" shaped) Some cheap one IC AM/FM radios use the same detector for both AM & FM, utilizing slope detection (Note that you have to disable any AFT circuits, as they will attempt to follow the signal and keep it centered). Cheers, Paul Grohe --------------------------------------------------------------- Paul Grohe National Semiconductor Corp. Sr. Electronics Technician 2900 Semiconductor Drive AMPS New Products Eng Group Mail Stop C2693 Mailto:grohe@galaxy.nsc.com Santa Clara, CA. 95052-8090 USA (408) 721-7389 Tel (408) 721-2513 Fax Usenet Disclaimer: Any opinions expressed are mine, not NSC's http://www.national.com For technical assistance, literature, or samples call: NORTH AMERICA EUROPE (800) 272-9959 (49) 814 110-3720 mailto:support@tevm2.nsc.com mailto:cnjwge@tevm2.nsc.com ---------------------------------------------------------------- From lwbyppp@epix.net Thu Mar 21 13:42:39 1996 From: dg715@cleveland.Freenet.Edu (David Mark) Newsgroups: alt.radio.scanner,alt.radio.pirate,rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc,rec.radio.scanner,rec.radio.shortwave,uk.radio.amateur Subject: Re: Weird Radio Problem Date: 16 Mar 1996 05:30:41 GMT Message-ID: <4idjm1$f0c@madeline.INS.CWRU.Edu> References: Reply-To: dg715@cleveland.Freenet.Edu (David Mark) Commercial airline frequencies are just above the statndard FM broadcast band. Your radio probably has a "cheap" tuner that doesn't just zero in on the desired frequency, but is subject to interference on nearby frequencies when a transmitter operating on those nearby frequencies is nearby (gee...how many more times could I squeeze the word "nearby" into that sentence?). What's happening is your radio is probably tuned to an FM station near the upper end of the band (around 107-108mhz) and you're probably under a flight path. When a plane is nearby (there's that word again) and the pilot transmits on one of the lower airline frequencies, your radio's less than discriminating tuner picks it up. -- (DAVID MARK) dg715@cleveland.freenet.edu From lwbyppp@epix.net Thu Mar 21 13:42:40 1996 From: bigd@mail.atw.fullfeed.com (Dennis Nuetzel) Newsgroups: alt.radio.scanner,alt.radio.pirate,rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc,rec.radio.scanner,rec.radio.shortwave,uk.radio.amateur Subject: Re: Weird Radio Problem Date: Tue, 19 Mar 96 15:26:05 GMT Message-ID: <4imjob$46g@ray.atw.fullfeed.com> References: >There is a small, minor detail: Air transmissions were AM, last time I >checked! How does an FM receiver with poor-selectivity receive AM >transmissions??? If close enough, it will. I have picked up CB radio transmissions (Also AM) on a nearby FM reciever. > From lwbyppp@epix.net Thu Mar 21 13:42:42 1996 From: Michael J Wooding Newsgroups: alt.radio.scanner,alt.radio.pirate,aus.radio,rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc,rec.radio.scanner,rec.radio.shortwave,uk.radio.amateur Subject: Re: Weird Radio Problem Date: Fri, 15 Mar 1996 20:14:59 +0000 Distribution: world Message-ID: References: In article , Peter Neidhardt writes >Does anyone have any idea what causes this? I thought >Commerical Airline bands were totally different and not even close to the >FM bands. I probably won't know the exact answer due to your location not being in my area! However, are you in the proximity of an AGA (Air-Ground-Air) station, used by Air Traffic Control for AGA communication? If so then it is simple breakthrough, as we tend to use quite high powers. If you do not then I would put the radio up for auction, or patent it! Regards ... Mike Michael J Wooding vhf-comm@g6iqm.demon.co.uk - CompuServe: 100441,377 WWW: http://www.eolas.co.uk/ag/vhfcomm.htm (hambits.htm & hamclip.htm) WWW: http://www.clearlight.com/~vhfcomm Tel: (0)1788 890365 Fax: (0)1788 891883 KM Publications, 5 Ware Orchard, Barby, Nr.Rugby, CV23 8UF, UK VHF Communications Magazine - Especially Covering VHF, UHF and Microwaves From lwbyppp@epix.net Thu Mar 21 13:42:43 1996 From: Michael J Wooding Newsgroups: alt.radio.scanner,alt.radio.pirate,rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc,rec.radio.scanner,rec.radio.shortwave,uk.radio.amateur Subject: Re: Weird Radio Problem Date: Tue, 19 Mar 1996 19:54:07 +0000 Distribution: world Message-ID: References: In article <314D9822.371D@vertex.ucls.uchicago.edu>, Isaac Kohn writes >checked! How does an FM receiver with poor-selectivity receive AM >transmissions??? Slope detection Mike Michael J Wooding vhf-comm@g6iqm.demon.co.uk - CompuServe: 100441,377 WWW: http://www.eolas.co.uk/ag/vhfcomm.htm (hambits.htm & hamclip.htm) WWW: http://www.clearlight.com/~vhfcomm Tel: (0)1788 890365 Fax: (0)1788 891883 KM Publications, 5 Ware Orchard, Barby, Nr.Rugby, CV23 8UF, UK VHF Communications Magazine - Especially Covering VHF, UHF and Microwaves From lwbyppp@epix.net Thu Mar 21 13:42:44 1996 Newsgroups: alt.radio.scanner,alt.radio.pirate,rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc,rec.radio.scanner,rec.radio.shortwave,uk.radio.amateur From: slwork@netcom.com (Steve Work) Subject: Re: Weird Radio Problem Message-ID: References: <4imjob$46g@ray.atw.fullfeed.com> Date: Tue, 19 Mar 1996 17:32:53 GMT Dennis Nuetzel (bigd@mail.atw.fullfeed.com) wrote: : >There is a small, minor detail: Air transmissions were AM, last time I : >checked! How does an FM receiver with poor-selectivity receive AM : >transmissions??? : If close enough, it will. I have picked up CB radio transmissions (Also : AM) on a nearby FM reciever. "AM rejection" is a spec which applies to FM radios. It is worse on cheaper ones. The circuitry used to detect FM signals can respond to changes in the amplitude. Especially when the circuit is cheap, and under conditions where it is overloaded. From lwbyppp@epix.net Thu Mar 21 13:42:45 1996 From: jlundgre@delta1.deltanet.com (John Lundgren) Newsgroups: alt.radio.scanner,alt.radio.pirate,aus.radio,rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc,rec.radio.scanner,rec.radio.shortwave,uk.radio.amateur Subject: Re: Weird Radio Problem Date: 16 Mar 1996 15:33:52 GMT Message-ID: <4ien10$afe@news02.deltanet.com> References: Peter Neidhardt (petern@terraport.net) penned: : I own a cheap General Electric boombox (about a $100 in value) that is a : few years old. It works well but when I am on a certain FM channel : listening to my favourite station, I intermittenly pickup actual radio : transmissions from overhead commercial airliners. These are actual : commercial airline communiques to the tower and back. I know it is : because the pilot states the airline and other info. like heading and : other number jumbo stuff. This is a simple radio with no short wave or : any extra bells or whistles and it works well except for the fact that : every so often it interupts the music and I hear aircraft communication : messages. Does anyone have any idea what causes this? I thought : Commerical Airline bands were totally different and not even close to the : FM bands. : Thanks greatly! : Peter Commercial airline freqs are right above the FM band. Your radio is receiving an image freq and detecting it even to it's AM and not FM. The airplane is probably really close, maybe overhead. Image freqs work something like this. The IF of the radio is 10.7 MHz, but let's just use 10 MHz. The radio station is at 100 MHz. The IF is 10, so the local oscillator is at 110 MHz. The receiver can receive at both the sum and difference of the two, so it can receive at either 100 MHz or 120 MHz. The 120 MHz is (somewhat) tuned out by the receiver's tuned circuits leaving the 100 MHz. But sometimnes the receiver doesn't do the tuning too well. And sometimes the unwanted transmitter is real close, so it gets thru anyway. If youre using the built-in rabbit ears, make sure they are fully extended. If you are always in a certain area, the location may be affecting the reception of your fav FM station, so try to maximize the signal by changing the location. You could also try reducing the signal strength by putting the antenna in the collapsed position. Maybe one of these might help enough to eliminate your problem. Another boombox might help, too. I bought some cheap soundesign radio in a bargain pack along with a flashlight and some batteries. I liked it because it received both FM and TV. But the receiver is atrocious, and receives all sorts of images of who knows what. It really sucks, but what can one expect when buying a radio and flashlight with batteries for twenty bucks? Not much, I guess. The Renewal batteries suck, too. They try to nail you later for the cost of the recharger! Forget it. -- #======P=G=P==k=e=y==a=v=a=i=l=a=b=l=e==u=p=o=n==r=e=q=u=e=s=t======# | John Lundgren - Elec Tech - Info Tech Svcs. | jlundgre@ | | Rancho Santiago Community College District | deltanet.com | | 17th St at Bristol \ Santa Ana, CA 92706 | http://rsc.rancho| | My opinions are my own, and not my employer's. | .cc.ca.us | | Most FAQs are available through Thomas Fine's WWW FAQ archive: | |http://www.cis.ohio-state.edu:80/hypertext/faq/usenet/FAQ-List.html| | "You can flame your brains out -- it won't take long." | #===T=u=z=l=a==C=o=m=p=a=n=y=.=.===t=h=r=e=e='=s==L=e==C=r=o=w=d=!==# From lwbyppp@epix.net Thu Mar 21 13:42:49 1996 From: jshaffer@mail.csrlink.net (Jim Shaffer, Jr.) Newsgroups: alt.radio.scanner,rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc,rec.radio.scanner,rec.radio.shortwave Subject: Re: Weird Radio Problem Date: Thu, 21 Mar 96 01:14:13 Message-ID: <19960321.7A374D8.13F1@localhost.UUCP> References: <314D9822.371D@vertex.ucls.uchicago.edu> In article <314D9822.371D@vertex.ucls.uchicago.edu> Isaac Kohn writes: > There is a small, minor detail: Air transmissions were AM, last time I > checked! How does an FM receiver with poor-selectivity receive AM > transmissions??? All you need to do to decode an AM signal is rectify it. Any transistor junction can act as a diode junction under the right circumstances. I know someone who gets nearby CB signals on his CD player -- no RF circuits at all, it's being picked up in the audio amp. -- * From the disk of: | jshaffer@mail.csrlink.net | "there's a hell of Jim Shaffer, Jr. | NOTICE: ^^^^^^^^^^^^^^^^ // | a good universe 37 Brook Street | I've changed // | next door; let's go" Montgomery, PA 17752 | Internet providers. \\// | (e.e. cummings) From lwbyppp@epix.net Thu Mar 21 13:42:50 1996 From: rst-engr@oro.net (Jim Weir) Newsgroups: alt.radio.pirate,rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc,rec.radio.scanner,rec.radio.shortwave,uk.radio.amateur Subject: Re: Weird Radio Problem Date: Thu, 21 Mar 1996 18:12:50 GMT Message-ID: <4is68q$h12@hg.oro.net> References: <4idjm1$f0c@madeline.INS.CWRU.Edu> <314D9822.371D@vertex.ucls.uchicago.edu> Michael J Wooding shared the following priceless pearls of wisdom: >In article <314D9822.371D@vertex.ucls.uchicago.edu>, Isaac Kohn > writes >>checked! How does an FM receiver with poor-selectivity receive AM >>transmissions??? >Slope detection >Mike Ummm...I came within a couple of milliseconds of falling into that same trap. Slope detection works for listening to FM on an AM rig; going the other way around requires imbalance in the ratio detector or discriminator -- not hard to do on a cheapie radio where the diode bridge are random diodes thrown into the board. Jim Jim Weir VP Engineering | You bet your sweet patootie I speak for the RST Engineering | company. If I don't, ain't nobody gonna. Grass Valley CA 95945 | http://www.rst-engr.com | AR Adv WB6BHI--FCC 1/C phone--Cessna 182A N73CQ rst-engr@oro.net | Commercial/CFI-Airplane/Glider-----A&P Mechanic From lwbyppp@epix.net Thu Mar 21 13:42:51 1996 From: blanton@ni.net (J. L. Blanton) Newsgroups: rec.radio.amateur.antenna Subject: What paint for antennas? Date: Sat, 16 Mar 1996 22:14:33 -0800 Message-ID: I have a HF vertical and some UHF Yagis which I want to paint to reduce their visibility. Does anyone know if there is a preferred type of paint for antennas? I painted a 2-meter antenna once using a thin coat of dark brown primer spray paint. It didn't seem to affect performance at all and made the antenna really hard to see. Many satellite dishes appear to be painted or have some other protective coating. Any info on what they use? Thanks in advance. Lee, WA8YBT/6 Temecula, CA From lwbyppp@epix.net Thu Mar 21 13:42:52 1996 From: rikoski@niia.net (Rick Rikoski) Newsgroups: rec.radio.amateur.antenna Subject: Re: What paint for antennas? Date: Mon, 18 Mar 1996 07:27:48 -0500 Message-ID: References: In article , blanton@ni.net (J. L. Blanton) wrote: > I have a HF vertical and some UHF Yagis which I want to paint to reduce > their visibility. Does anyone know if there is a preferred type of paint > for antennas? I painted a 2-meter antenna once using a thin coat of dark > brown primer spray paint. It didn't seem to affect performance at all and > made the antenna really hard to see. Many satellite dishes appear to be > painted or have some other protective coating. Any info on what they > use? Thanks in advance. >============================================================================= = Paint em. Probably won't make any difference. Hardware store spray paint has pretty good dielectric properties. One caution though. I'll bet you will be painting aluminum antennas. Plastic paint won't stick too well on that. Will chip easily. So you will want to prime the antenna first. The usual chromium compound primers are fair rf conductors, so while there should be no problem painting reflectors and directors, you should be careful around the driven element. -- Rick Rikoski Chicago/Indiana Dunes rikoski@niia.net From lwbyppp@epix.net Thu Mar 21 13:42:53 1996 Newsgroups: rec.radio.amateur.antenna From: dstock@hpqmdla.sqf.hp.com (David Stockton) Subject: Re: Where do S reports go to, anyway ? Message-ID: Date: Wed, 13 Mar 1996 14:47:34 GMT References: <4i3pav$124@news.hal-pc.org> : Maybe the manufacturers will see it as a marketing opportunity and : include a digital readout adjacent to or within the face of the analog : meter. They could add a button and it would freeze the display so the : operator would not forget what it was. Given the microprocessors-with-everything style of current boxes, with LCD S-meters, Digital, numeric readout of "S" is trivially easy. Just because something is written in numbers doesn't mean that it will be usefully accurate, though. The meter isn't the problem. They monitor the AGC line voltage, and so the meter reading is distorted by the AGC'd amplifiers gain versus control voltage relationship which is not prticularly linear, and varies too much from unit to unit, and over temperature, to make correction much help. Also, the thing is out of action when manual RF gain is selected. Good S meters could be done, but a big chunk of IF circuitry would need to be designed quite differently to the current traditional style. Display doesn't matter too much if the foundation of the measurement is dodgy : Anyway, I suspect if S reports had to go somewhere, that's where they : would go, right? Like the Ancient Mariner's albatross ? Right ! Cheers David From lwbyppp@epix.net Thu Mar 21 13:42:54 1996 From: gpritcha@vanieee.wimsey.bc.ca (Gordon Pritchard) Newsgroups: rec.radio.amateur.antenna Subject: Re: Where do S reports go to, anyway ? Date: Wed, 13 Mar 1996 21:01:51 GMT Message-ID: <4i7d9o$4lp@fountain.mindlink.net> References: <4i3pav$124@news.hal-pc.org> Reply-To: gpritcha@vanieee.wimsey.bc.ca dstock@hpqmdla.sqf.hp.com (David Stockton) wrote: >: Maybe the manufacturers will see it as a marketing opportunity and >: include a digital readout adjacent to or within the face of the analog >: meter. They could add a button and it would freeze the display so the >: operator would not forget what it was. > Given the microprocessors-with-everything style of current boxes, >with LCD S-meters, Digital, numeric readout of "S" is trivially easy. > Just because something is written in numbers doesn't mean that it >will be usefully accurate, though. The meter isn't the problem. They >monitor the AGC line voltage, and so the meter reading is distorted by >the AGC'd amplifiers gain versus control voltage relationship which is >not prticularly linear, and varies too much from unit to unit, and over >temperature, to make correction much help. Also, the thing is out of >action when manual RF gain is selected. > Good S meters could be done, but a big chunk of IF circuitry would >need to be designed quite differently to the current traditional >style. Display doesn't matter too much if the foundation of the >measurement is dodgy I for one wouldn't want to pay for an accurate S-meter. I use my TS-850's S-meter as a guide only. The S report I give is based on a myriad of factors, like background band noise, other signals, my mood :-). If the band is darn near dead, but there's a guy who's twitching the meter, I'll give him an S report that's more optimistic than any meter reading. Conversely, hot band (all readings high) and I'll give a Scotch S report! So, yes, the technology is there, the engineering could be applied, but I wouldn't thank you for it! YMMV. Gordon Pritchard, VE7AGW *********************************************************************** * My opinions only. * * E-mail: gpritcha@vanieee.wimsey.bc.ca * * 1954 Chev 1/2 ton (perpetual project) * * -small-block, posi, frame stretch...* *********************************************************************** From lwbyppp@epix.net Thu Mar 21 13:42:55 1996 From: ericr@access1.digex.net (Eric Rosenberg) Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.space Subject: Windload for helix antenna? Date: 12 Mar 1996 16:49:36 -0500 Message-ID: I have a 16-turn, 10 ft long G3RUH 70cm helix with an 18" square screen as the reflector. I'd like to figure out the windloading for this antenna. Can anyone suggest either the windload itself or how to calculate it. Thanks, Eric -- Eric Rosenberg WD3Q, EI4VPS, YJ0AER, J20BY, etc. Washington, DC ericr@access.digex.net wd3q@amsat.org From lwbyppp@epix.net Thu Mar 21 13:42:57 1996 Newsgroups: rec.radio.amateur.antenna From: n4lq@iglou.com (Steve Ellington) Subject: Re: Windom comparisons Message-ID: References: <4ic6nh$2at@hp5.online.apple.com> Date: Fri, 15 Mar 1996 17:59:28 GMT Wow, what a question. One could write a book on this. Hmmm, maybe they already have. I believe we are trying to reach utopia. All bands, low swr and no loss. Anything you try is going to be a compromise! Windoms work but keep in mind that on the higher bands you will experience some very deep nulls and sharp lobes. This goes for any antenna used on frequencies higher than 1/2 wavelength. Even a dipole has directional qualities but not as severe as an 80 meter dipole or windom on 15 meters! You will experience dead zones. All of these antennas will work to an extent BUT don't expect it to have a low swr on all bands. If it does, something is wrong. Probably there is a bunch of RF loss on either your tuner, feedline or balun. As for Radio Works Carolina Windom , they just took of advantage of a bad thing. That is "feeder radiation". By feeding the windom with unbalanced line, it simply radiates. Then they attempt to choke it off at about the 21ft point from the feed point. I would think that different amounts of radiation would occur at various frequencies. How much? Who knows. Anyone been able to figure that out? : I'm considering putting up a windom-type antenna, ie an off-center fed : dipole. I've seen three different companies that advertise them: Antennas : West, Fritzel, and Radio Works. Has anyone done a comparison of these? Is : there much difference between them? I do know that RadioWorks has a : vertical radiator that is part of there antenna. Does that make much : difference? Finally, any comparisons between these type antennas and a : G5RV? -- Steve Ellington N4LQ@IGLOU.COM Louisville, Ky From lwbyppp@epix.net Thu Mar 21 13:42:58 1996 From: wa4pgm@moonstar.COM Newsgroups: rec.radio.amateur.antenna Subject: wire beams Date: 19 Mar 96 15:20:00 GMT Message-ID: Hello all I would like to build some wire beams between 2 towers here, possibly trees or poles. Need antennas to work 20-15-10 meters and have about 100' spacing to play with between towers. Wonder if some of you could give me any ideas, what worked for you ? 73 Kyle ------------------------------------- Name: kyle chavis E-mail: wa4pgm@moonstar.com Date: 03/19/96 Time: 10:20:00 This message was sent by Chameleon ------------------------------------- From lwbyppp@epix.net Thu Mar 21 13:42:58 1996 Newsgroups: rec.radio.amateur.antenna From: Craig Harlamoff KF6BJW Subject: WTB Johnson Match box Date: Thu, 14 Mar 1996 04:46:11 GMT Message-ID: <3147A493.1995@cruzio.com> Hi, WTB a Johnson Match box to tune my HF antenna. craighar@cruzio.com Santa Cruz CA KF6BJW From lwbyppp@epix.net Sun Mar 24 17:20:51 1996 From: Isaac Kohn Newsgroups: rec.radio.amateur.antenna Subject: Re: "floating" the output of a tuner. Date: Mon, 18 Mar 1996 09:16:00 -0600 Message-ID: <314D7E30.347D@vertex.ucls.uchicago.edu> References: <4hsvn5$a51@news.cis.okstate.edu> <1996Mar10.223737.7115@ke4zv.atl.ga.us> Gary Coffman wrote: > L1----)))----x----)))----L3 > | > IN = OUT *unbalanced* T net > | > L2-----------x-----------L4 > > L1----)))----x----)))----L3 > | > IN = OUT *balanced* H net > | > L2----)))----x----)))----L4 Would it be possible to add a balun (1:1 or otherwise) to the input of the H network and therefore have an unbalanced-to-balanced-tuner?? That way, you could combine the transition from coax to balanced with the tuner. Anyway, doesn't it make sense that the place where you switch from one impedance line to another is the same place where you tune impedances?? Just a thought.... Isaac From lwbyppp@epix.net Sun Mar 24 17:20:54 1996 From: John Passaneau Newsgroups: rec.radio.amateur.antenna Subject: Re: "Hamstick" dipole troubles Date: Mon, 18 Mar 1996 09:18:04 -0800 Message-ID: <314D9ACC.6BF7@leps.phys.psu.edu> References: <4iev07$amc@inxs.ncren.net> To: Derrick Cole Derrick Cole wrote: > > Greetings! > > At the Charlotte HamFest last weekend, I purchased two 40M "HamStick" antenn as > (HF mobile whips?) consisting of a coiled mast and an extendable metal "whip ", > which, when adjusted, supposedly allow for tuning for a certain center > frequency. I also bought a mounting bracket so as to create a dipole from > the two 'sticks. > > Suffice to say, I've not had much luck. Initially, with the whips fully > extended, I could only achieve 3+:1 across 40M except for the upper 30KHz, > where I could get 1-8-2:1. > > Wanting a lower SWR in the lower 100KHz, I set out to actually read the > confusing instructions about the whip and tuning for a certain frequency. > Choosing a frequency of 7.1MHz, this implies an exposed whip length of > 39". I cut both whips to 39.5" (39" of which was exposed), tightened > everything up, tuned up on 7.1MHz, and now enjoy 5:1 SWR everywhere. > > Obviously, I've done something wrong. Can anyone offer ANY advice on such > a contraption? Where might I obtain replacement whips (which were originall y > 48.25" long)? What should I do? > > Thanks and 73, > DerrickHi Derrick: I have made a cross dipole antenna out of 4 hamsticks (2 on 40 and 2 on 80) I had no trouble geting a 1:1 SWR on 80 or 40 meters. The SWR bandwidth is only about 65KHz but that is no worse than expected. I made a mounting fixture out of PVC pipe that mounts the antennas at right angles to each other and forms a short mounting mast to use with a chimmly mount. I looks like a big war club with out the whips on it. I didn't need any caps or other stuff to get the SWR down I just adjused the whips with the thing on a step ladder in the back yard. I would check on one thing with your whips though. On some of the hamsticks, if you push the whips tips too far into the black bit, you can snap the wire that connects the metal tip the whips go through from the loading coil. I would check the resistance from the metal mounting stud to the metal tip on the end of the black rod. I should be quite low in resistance. I found the cuting charts no to be much help when making dipoles out of the hamsticks, as they are based on using the antennas as vertical on a car body and thats not the way they are used in this case. I think that it works just about as well as the text books say it should. It is not an efficant antenna, no moble or very shorted antenna is. -- *************************************************** * JOHN PASSANEAU, WB8EIY * * Penn State University, University Park, Pa. * * My opinions are my own, not my employers. * *************************************************** From lwbyppp@epix.net Sun Mar 24 17:20:55 1996 Newsgroups: rec.radio.amateur.antenna From: Paul Moller Subject: Re: 2m antenna for travel Date: Wed, 20 Mar 1996 09:30:11 -0600 Message-ID: <31502483.3CE@csg.mot.com> References: Charlie Fortner wrote: > > I am going on a trip with the local Boy Scout troop out west this summer > and I want some opinions on what antenna(s) I should bring for the times > we are in a building (a hotel of some sort). I have an Icom IC-T22A > handheld with a Larsen 5/8 wave mag mount (to use on the van when we are > mobile - I really don't want to have to take it off the van for use > inside). I was thinking about making a J-Pole out of copper pipe and > using that, but it would be bigger than I would like it to be. Any ideas, > suggestions, or the like would be greatly appreciated. > BTW - any mods for an IC-2000H would also be appreciated! Thanx! > > -- > Ted Fortner > Wozniac@netdepot.com > KF4GJR MFJ makes a nice little "roll up" 2m j-pole. It can be hung from the ceiling with a thumb tack. Or make your own. Paul_Moller@csg.mot.com From lwbyppp@epix.net Sun Mar 24 17:20:58 1996 From: chideste@xvnews.unconfigured.domain (Dale Chidester) Newsgroups: rec.radio.amateur.antenna Subject: Re: 2m antenna for travel Date: 22 Mar 1996 16:19:41 GMT Message-ID: <4iujut$9bv@igate2.pt.cyanamid.com> References: <3150174E.794B@raleigh.ibm.com> Reply-To: chideste@xvnews.unconfigured.domain I copied this from the newsgroup some time ago and thought it might be of inte rest again now. 73, Dale ------------------------------------------------------------------------ Dale H. Chidester, PhD N3HAL "Against stupidity, even the Cyanamid Agricultural Research Center Gods in vain doth contend." Process Development Facility Schiller PO Box 400, Clarksville Rd. Phone: (609) 716-2430 Princeton, NJ 08543-0400 Email: chidesterd@pt.cyanamid.com ------------------------------------------------------------------------ From clint.bradford@woodybbs.com (Clint Bradford) Newsgroups: rec.radio.amateur.antenna Subject: Re: J-Pole antenna? Date: Mon, 18 Sep 95 10:17:00 -0500 RM>>Does anyone out there have the info on making a j-pole out of twin lead >>tv antenna wire? === 2m/70cm Dual Band J-Pole made from 300 ohm twin lead === _____ _______ ___ | | | | | | O | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 54-1/4" | | 38-1/2" | | | | | | | | | | | | | | _| | | | N |_ _|__ | | | | | | | | | | | | | | | | | | | 15-3/4" | | | | | |_______| ___ | | | | 1/4" | _|_ | | ___ _|__ ^ ^ | | Coax Inner Coax Outer Conductor Conductor SWR is 2:1 across the 2m band and from 435mhz to 450mhz on the 70cm band. 1. Use good quality TV twin lead. 2. Strip insulation at the solder point for coax feedline. 3. Cut out and remove the 1/2" long notch N. 4. Feed with a length of 50 ohm coax and terminate with the appropriate connector. Tape coax at feedpoint to the twin lead, or use heat shrink, and make sure the joints are insulated from each other. 5. Antenna may be sleeved inside 1/2" PVC for outside mounting or hung on a loop of string run thru hole O. Clint * 1st 2.00 #8286 * "640k should be enough for anybody" - Bill Gates, 1981. --- ‏ wcECHO 4.1 ק AR-Net: ATTENTION to Details ‏ Mira Loma, CA ‏ 909-681-6221 From lwbyppp@epix.net Sun Mar 24 17:20:59 1996 From: Shelby Merrick Newsgroups: rec.radio.amateur.antenna Subject: 3 Element VHF Yagi Date: Thu, 21 Mar 1996 15:00:23 -0500 Message-ID: <3151B557.22DD@som-uky.campus.mci.net> Would anyone happen to have plans for a small 2 meter 3 or 4 element yagi? I am trying to build an antenna to go indoors in a second story apt., but still get modest gain. I have seen one made by mfj that is 3 element and 2.75' long. Has anyone used here used this antenna before? If so, what's the gain on it, and does perform well? Thank you for the info. 73's Shelby KE4AKA From lwbyppp@epix.net Sun Mar 24 17:20:59 1996 From: tom_boza@ccm.ch.intel.com (WB7ASR) Newsgroups: rec.radio.amateur.antenna Subject: 300 vs 450 ohm ladder line Date: 21 Mar 1996 17:07:55 GMT Distribution: world Message-ID: <4is2db$8oj@chnews.ch.intel.com> What are the major differences and advantages/disadvantages of using either? What about wire gage? Catalogs sell different sizes. From lwbyppp@epix.net Sun Mar 24 17:21:03 1996 From: shssci@li.net Newsgroups: rec.radio.amateur.antenna Subject: Re: adhesive copper tape Date: Tue, 19 Mar 96 09:44:47 PDT Message-ID: References: In Article, write: > Newsgroups: rec.radio.amateur.antenna > Path: li.net!news5.ner.bbnplanet.net!news.ner.bbnplanet.net!howland.reston.a ns.net!Germany.EU.net!Frankfurt.Germany.EU.net!news.maz.net!news.allcon.net!jg fl1!griffin > From: griffin@jgfl1.allcon.com (Jens Goerke) > Subject: Re: adhesive copper tape > X-Newsreader: TIN [version 1.2 PL2] > Organization: Private Multi-Site > Message-ID: > References: > Date: Mon, 18 Mar 1996 20:25:43 GMT > Lines: 23 > > shssci@li.net wrote: > [...] > > My own application is installing a counterpoise system inside a fiberglass > > sail boat for an automatic antenna tuner working the 40M to 15M bands. (2 50W > > PEP?) The antenna is the backstay which, on my boat, puts the tuner in a b ad > > spot for a direct-to-the-water ground of sufficient area. (Plus potential for > > electrolysis problems.) So, I'm going to use counterpoise system below wa ter > > line. I don't want to use loose wires for that and attaching them or regu lar > > copper foil to the hull would be an adventure with all the structural stuf f in > > the way. The self-adhesive feature might solve this, too. > [...] > > How about a metal rudder > IMHO this would make a rather good ground connection. > What about the keel? On smaller sailing boats they are usually made > from lead, so that would be another possibility. > > Just my $.02, > Jens, DB9LL > -- > Missing coffee error - operator halted. > > This message may not be distributed via the Microsoft Network. de KD2FT Hi, Jens - thanks for the thoughts on grounding. Normally, these would be worthy possibilities, but the specifics of my boat preclude me from making effective electrical contact with either. In building my boat (35' double-ended cutter, 6' draft), I had to cast my own keel. It is 6300 pounds of lead, but it is all internal, down in the molded fiberglass keel cavity. To manage that job, I cast it in three layers of many separate blocks each. Each block was carefully cast to match the shape of the keel cavity at the place where that block would go, and in a size that I could carry up into the boat and back down into the hull (no internal structures yet) and position properly in the keel cavity, without getting killed. These blocks run about 100 to 150 pound each. After a layer of blocks was positioned, I "potted" the blocks in resin and than fiberglassed over the whole layer as both a securing agent for that layer, a base for the next layer and to form a water-tight layer in the (hopefully unlikely) event that I ground the boat and cause the existing bottom of the fiberglass keel to leak. Then the next layer was cast, installed, potted and glassed over, etc. The net result is that the keel is now composed of many separate and electrically isolated blocks. As for the rudder, I also made that. It has a large, very rugged "core" of stainless plate and the rudder stock, but it is inside a fiberglass shell filled with microballoons. The rudder stock runs through a trunk made of fiberglass tube from the hull to deck-level. At deck-level, it enters the tiller-head. It would probably be OK as a capacitively-coupled ground, but the result here is that it, too, is electrically unaccessable. The only moving connection I could envision would be some kind of brush or wiper contacting the rudder stock through the fiberglass rudder trunk. I don't think this would be a good connection for long. Net result is that I believe I have to consider another method than the rudder or the balast. That leads me to the counterpoise system, and thence to the installation problems of regular (wide) copper foil, now that all the interior structures and systems are in the way. There-in lies the reason for inquiring about foil counterpoise systems in general, and the self-adhesive, thin foil tape in specific. Thanks very much for your thoughts - all help is greatly appreciated as it helps me avoid "reinventing the wheel". 73 KD2FT Frank Fitz... and the crew of the mighty Draco shssci@li.net From lwbyppp@epix.net Sun Mar 24 17:21:03 1996 From: cmoore@vegas.ch.intel.com (Cecil A. Moore~) Newsgroups: rec.radio.amateur.antenna Subject: Re: Aerial length Date: 24 Mar 1996 00:24:43 GMT Distribution: world Message-ID: <4j24ob$1562@chnews.ch.intel.com> References: In article , Mark Nissen wrote: >I've got a Radio controlled car with no aerial on the control device >which reads 27.145 MHz. Could some one tell me the correct length of aerial >I need to put on it? If you are a purist, go get a 109 inch whip from Radio Shack. If you are not a purist, a foot or so will do. 73, Cecil, KG7BK, OOTC (not speaking for my employer) From lwbyppp@epix.net Sun Mar 24 17:21:05 1996 From: ka_strom@ix.netcom.com(Kevin Alfred Strom) Newsgroups: rec.radio.amateur.antenna Subject: Re: AM antennas??? Date: 19 Mar 1996 09:02:27 GMT Message-ID: <4ilt73$p5v@cloner4.netcom.com> References: <4i8cbj$jo7@news.halcyon.com> <4il2su$ais@newsbf02.news.aol.com> One of my favorite 75/160 mtr antennas is an inverted L, 150 feet in total length, fed against just 4 120' radials lying on the ground. I have made the vertical portion anywhere from 40 to 90 feet of the total, depending on local trees. The "vertical" portion can in fact be curved to fit the outer shape of a large tree without any problems, in my experience. I feed with an L network at the base. Always beats a dipole on 75, I have found. AND IT MAKES A GREAT BCB antenna! I recently lived near the WV/VA line, and WLW Cincinnati was a full-quieting daytime signal on my inverted L! 50-kw Washington DC, Richmond, Detroit, Chicago, South Carolina, Louisville and Cleveland stations were all readable in the DAYTIME via GROUNDWAVE, as long as there were no nearby thunderstorms. Almost EVERY channel had a readable signal on it. Receiver was a Kenwood TS440 with the MW attenuator disabled. I highly recommend such an inverted L as a MW antenna. Good luck, Kevin Alfred Strom, WB4AIO From lwbyppp@epix.net Sun Mar 24 17:21:05 1996 From: dabloodgod@aol.com (DABLOODGOD) Newsgroups: rec.radio.amateur.antenna Subject: Re: Antenna Analyzers: AEA vs. MFJ Date: 21 Mar 1996 08:56:51 -0500 Message-ID: <4irn73$rns@newsbf02.news.aol.com> References: <4id1p0$mrp@newsbf02.news.aol.com> Reply-To: dabloodgod@aol.com (DABLOODGOD) I have an MFJ 209 HF/VHF analyzer - which works well, BUT check the calibration before you use it - mine was WAY OFF. I got a 3 dB and a 6 dB pad from work, and used them to simulate a 6, 12 and 18 dB return loss ( screw them on, leave other end open ). With the cal pads on, there is a pot inside the unit to adjust the meter reading. I didn't get a schematic with mine, so I can't really be more precise, than to say to adjust the pot that is in series with the meter. Good luck and 73's de Dave, kd6pro From lwbyppp@epix.net Sun Mar 24 17:21:06 1996 From: Isaac Kohn Newsgroups: rec.radio.amateur.antenna Subject: Re: Antenna for apartment Date: Mon, 18 Mar 1996 09:25:16 -0600 Message-ID: <314D805C.1187@vertex.ucls.uchicago.edu> References: <4hicb8$msv@bolivia.it.earthlink.net> <4hmtb0$o67@crash.microserve.net> <4i49nl$3fa@ecuador.it.earthlink.net> <4i4h8a$eka@crash.microserve.net> WB3U wrote: > > kb6ojs@earthlink.net (Steve Silverwood) wrote: > > >Just out of curiosity, is there a real advantage between using > >twin-lead for the feed over using coax with a balun? > > A balun is likely to cause problems in this situation whether it's at > the tuner (twinlead feeder) or at the antenna (coax feeder). In your > situation, assuming the feedline is short, losses in the line will > probably be secondary to problems that will potentially be > generated by a balun. > > As Tom, W8JI, has pointed out, a choke balun is the most immune to the > ill-effects of feeding a high impedance load. However, even if it > doesn't consume power, it will can still lose balance. Given your > situation and the need to keep RFI to an absolute minimum, a balanced > tuner is the optimum solution. > > 73, > Jack WB3U Hi, I've been following this because I have the same problem. If I use twin-feed and a balanced tuner, then would I just put a balun before the tuner, or would I have to do something more fancy? Also, is a loop-skywire impractical? From lwbyppp@epix.net Sun Mar 24 17:21:08 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: Antenna for apartment Date: Fri, 22 Mar 96 19:33:47 GMT Message-ID: <4iuvld$rmo@crash.microserve.net> References: <4hicb8$msv@bolivia.it.earthlink.net> <4i4h8a$eka@crash.microserve.net> <314D805C.1187@vertex.ucls.uchicago.edu> <4ilp33$fhd@crash.microserve.net> <4iuic9$181u@chnews.ch.intel.com> cmoore@vegas.ch.intel.com (Cecil A. Moore~) wrote: >WB3U wrote: >>A link-coupled balanced tuner eliminates the need for a balun. It >>transforms the unbalanced output of the transmitter to balanced feed >>by means of tuned L/C components. >Hi Jack, my balanced tuner positions a single variable capacitor >across the 300 ohm ladder-line to eliminate reflections at that >point so I have an SWR of 1:1 on the ladder-line at the shack. >I'm presently using a 4:1 voltage balun at that point. Do you >think a link-coupled air-core transformer would work better? Hi Cecil, I guess the answer to that depends on your situation. After the thread on baluns, single-ended tuners etc., I did some more reading on the subject. The configuration you're describing has one shortcoming; common mode currents can travel through the balun and tuned components. At least three potential problems can result. First, if you live near a strong BCB or other commercial station, common mode current generated on the antenna and feedline by those signals may be only slightly attenuated by the tuner before reaching the front end of the receiver. Second, if your transmitter exhibits less than optimum harmonic rejection, they can also travel through the tuner with little or no attenuation. Finally, according to Tom, W8JI, even a symmetrical system like this can generate high on-frequency common mode voltages on the feedline. That means the voltage will be across your balun, and that the balun's inter-winding capacitance can allow RF current to flow back to the chassis of the rig. I'll admit that I don't understand the mechanism that causes common mode voltages to appear in a symmetrical system though. Maybe it's time to take Tom up on his offer to explain this in more detail. In any event, an air-core link doesn't allow those voltages to create significant current flow between the feedline and transmitter. The tuner you're using is the same as the "Measures" tuner - you've just eliminated some of the L/C components. I've run into a number of people on the air who were using a symmetrical tuner with an input balun, and none seem to be experiencing problems as far as RF currents in the shack. In addition, most of the operators are using current baluns, which I would expect to be more susceptible to the problem than your voltage balun. So, at this point I'm wondering just how likely it is that a symmetrical tuner, feedline and antenna will create common mode voltage sufficient to be problematic in the real world. I'm referring only to shack RF currents here - in many situations, outside signal sources and harmonics aren't a big concern, although the potential for those problems still needs to be recognized. >>The best solution is to either build a balanced tuner or buy a used >>Johnson Matchbox (manufactured in the 50's/60's). >My balanced tuner is a single variable capacitor so it is a very >simple and inexpensive way to go. Yes, a single variable capacitor >will cause an SWR of 1:1 when it is positioned and adjusted >properly. I'm working on an autotuner that will do just that >automatically. That system won't work for me due to unrelated restrictions, but I like the simplicity. The only question that remains is whether you will experience symptoms of common mode voltage. This is why I was trying earlier to build a balun with very low inter-winding capacitance. If that could be accomplished, it would allow using any simple means to tune a balanced line. As long as the technique was symmetrical (like your parallel capacitor), none of the problems mentioned above would exist. Good luck with the autotuner. Do you think the control circuitry would be applicable to a link tuner with three variable caps and a 9 position bandswitch? ;) 73, Jack WB3U From lwbyppp@epix.net Sun Mar 24 17:21:09 1996 From: cmoore@vegas.ch.intel.com (Cecil A. Moore~) Newsgroups: rec.radio.amateur.antenna Subject: Re: Antenna for apartment Date: 22 Mar 1996 15:52:41 GMT Distribution: world Message-ID: <4iuic9$181u@chnews.ch.intel.com> References: <4hicb8$msv@bolivia.it.earthlink.net> <4i4h8a$eka@crash.microserve.net> <314D805C.1187@vertex.ucls.uchicago.edu> <4ilp33$fhd@crash.microserve.net> In article <4ilp33$fhd@crash.microserve.net>, WB3U wrote: > >A link-coupled balanced tuner eliminates the need for a balun. It >transforms the unbalanced output of the transmitter to balanced feed >by means of tuned L/C components. Hi Jack, my balanced tuner positions a single variable capacitor across the 300 ohm ladder-line to eliminate reflections at that point so I have an SWR of 1:1 on the ladder-line at the shack. I'm presently using a 4:1 voltage balun at that point. Do you think a link-coupled air-core transformer would work better? >The best solution is to either build a balanced tuner or buy a used >Johnson Matchbox (manufactured in the 50's/60's). My balanced tuner is a single variable capacitor so it is a very simple and inexpensive way to go. Yes, a single variable capacitor will cause an SWR of 1:1 when it is positioned and adjusted properly. I'm working on an autotuner that will do just that automatically. 73, Cecil, KG7BK, OOTC (not speaking for my employer) From lwbyppp@epix.net Sun Mar 24 17:21:10 1996 From: rikoski@niia.net (Rick Rikoski) Newsgroups: rec.radio.amateur.antenna Subject: Re: Antenna Help - don't be mad Date: Tue, 19 Mar 1996 09:26:33 -0500 Message-ID: References: <4ijpvl$mb8@white.lambton.on.ca> In article <4ijpvl$mb8@white.lambton.on.ca>, rupfold@white.lambton.on.ca (Rod Upfold) wrote: > Please do not get mad..... > > I have looked for other antenna groups but could not find one..... > > My problem is with a television antenna. I have a combination head hooked > up to an antenna pre-amp. > > My question is: can connect via a 300 ohm flat wire another uhf head to > the combination head...and both go through the pre-amp.... > > I relly could use the help....local sellers do not know "dick" and I need > help from an expert. > > Thank you > Rod Upfold > -- ======== Yes maybe. Make sure that: You don't overload your amp. Causes cros-mod (squiggly lines on the picture) Radiate signal like a transmitter to interfere with your neighbors. You may want to do all of this using coax instead of twin lead. You might want to combine signals with a balun type splitter connected as a combiner. -- Rick Rikoski Chicago/Indiana Dunes rikoski@niia.net From lwbyppp@epix.net Sun Mar 24 17:21:11 1996 From: parf@aol.com (Parf) Newsgroups: rec.radio.amateur.antenna Subject: Re: Antenna Modeling Software Date: 20 Mar 1996 23:03:07 -0500 Message-ID: <4iqkdr$a48@newsbf02.news.aol.com> References: <31506320.2048486@news.borg.com> Reply-To: parf@aol.com (Parf) Hi Scott, QST recently reviewed several packages. I own about all of them and find K6STI's software the most flexible because it allows optimization- i.e. you can enter element lengths, spacings etc. as variables or equations. The optimizer then can be set w/ tradeoffs between gain, f/b, match etc. His Yagi program is YO6.5 while general wire modeling is AO2.5 (think that is the latest). 73, Dale WA2YPY From lwbyppp@epix.net Sun Mar 24 17:21:13 1996 Newsgroups: rec.radio.amateur.antenna From: gary@ke4zv.atl.ga.us (Gary Coffman) Subject: Re: Antenna or Mast Amp - which is better ? Message-ID: <1996Mar17.181400.11964@ke4zv.atl.ga.us> Reply-To: gary@ke4zv.atl.ga.us (Gary Coffman) References: <4i2538$7di@nntp.ucs.ubc.ca> Date: Sun, 17 Mar 1996 18:14:00 GMT In article <4i2538$7di@nntp.ucs.ubc.ca> djones@ucs.ubc.ca (David Jones) writes : >This is a VHF/UHF TV question, I know, but please bear with me - I couldn't >find any newsgroups on Antennas other than this one... > >I live in Delta, B.C., about 120 miles north of Seattle, WA and wish to >recieve more US TV channels... I have a roof mounted antenna which is >capable of recieving one Tacoma station, albeit very noisy. I want to >recieve Seattle stations, too, and wanted to know if it was better to buy a >mast mounted "booster" amplifier (with say 20 to 30 dB gain) or replace my >antenna with a "deep fringe" type. My antenna is about six feet long, with >about 20 elements, I recall. The "deep fringe" all channel antennas don't have good patterns, so one of those may not help much. However, a long boom single channel yagi can improve things dramatically. A preamp can also be used to set the system noise floor, but the typical wideband TV preamp won't do. You need a commercial quality single channel low noise amplifier. Both of these items are available from commercial suppliers. Gary -- Gary Coffman KE4ZV | You make it, | Due to provider problems Destructive Testing Systems | we break it. | with previous uucp address es 534 Shannon Way | Guaranteed! | Email to ke4zv@radio.org Lawrenceville, GA 30244 | | From lwbyppp@epix.net Sun Mar 24 17:21:14 1996 From: zandor1@aol.com (ZANDOR1) Newsgroups: rec.radio.amateur.antenna Subject: Beam Antenna for 27Mhz Date: 22 Mar 1996 00:10:03 -0500 Message-ID: <4itcnb$i7m@newsbf02.news.aol.com> Reply-To: zandor1@aol.com (ZANDOR1) I would like to try something different and would appreciate any help that can be given. I do not want to get a linear for my car. I would like to know if it is possible to build or buy a beam antenna for CB radio? If so how is it done? Thanks in advance for any help From lwbyppp@epix.net Sun Mar 24 17:21:14 1996 From: redbone@juno.COM (Douglas R Davis) Newsgroups: rec.radio.amateur.antenna Subject: Car AM Antennas to 2 Meter Date: 17 Mar 96 00:50:25 GMT Message-ID: <19960317.125602.14255.1.redbone@juno.com> Here is the results after searching the Thomas Register for Stico Sti-Co Industries Inc. Orchard Park, NY 14127-4187 USA 716-662-2680 FAX: 716-662-5150 Antennas, Couplers, Tuners & Systems. From lwbyppp@epix.net Sun Mar 24 17:21:16 1996 From: guenter.koellner@oen.siemens.DE (Koellner, Guenter) Newsgroups: rec.radio.amateur.antenna Subject: RE: European 4 to 5 wavelength boom 144 Date: 18 Mar 96 21:27:00 GMT Message-ID: <314DD58A@SmtpGate.Oen1.Oen.Siemens.De> | Date: Fri, 15 Mar 1996 09:05:14 +0300 | From: Ilkka Kontola | Subject: European 4 to 5 wavelength boom 144 MHz Yagis? | | Is there European manufacturers for four to five wavelength | boom 144 MHz Yagi antennas? | If any is there any references concerning their usability | in four or six yagi EME arrays? | | -- | Ilkka Kontola Amateur radio: oh3njc | Nokia Mobile Phones | Tampere, Finland | Hello, I would prefer the DJ9BV yagis as they were introduced in a DUBUS. They are available ready-made, e.g. here are prices as for Eisch electronic, Ulm, Germany: Name Elem. Gain Boomlen Price Boom Support BVO2-2 8ele 12.1 dBd 4.285m DEM 226,- single boom only BVO2-3 10ele 13.4 dBd 6.404m DEM 295,- overhead cord support BVO2-4 15ele 14.2 dBd 8.340m DEM 363,- overhead cord support BVO2-5 18ele 15.0 dBd 10.495m DEM 385,- overhead cord support BVO2-6 20ele 15.65dBd 12.520m DEM 454, v-brace/cord support Originally these yagis were designed by DL6WU, but DJ9BV optimized them. The description in DUBUS gives all datas for homebrewing. As they are very easy to be built and if you have simple machines they are easy to be homebuilt. Just lately they became available ready-made, too. There are some others available by M2 from somewhere, but their prices is even higher. If you want to see the antennas watch my homepage... vy 73, Guenter, DL4MEA@DB0KCP.#BAY.DEU.EU (AX.25) dl4mea@amsat.org (Internet) http://www.scn.de/~koellner (WWW) From lwbyppp@epix.net Sun Mar 24 17:21:17 1996 Newsgroups: rec.radio.amateur.antenna From: gary@ke4zv.atl.ga.us (Gary Coffman) Subject: Re: G5RV coax length Message-ID: <1996Mar20.184524.24560@ke4zv.atl.ga.us> Reply-To: gary@ke4zv.atl.ga.us (Gary Coffman) References: <4i7itu$g19@news1.inlink.com> <4icldt$i20@newsbf02.news.aol.com> Date: Wed, 20 Mar 1996 18:45:24 GMT In article <4icldt$i20@newsbf02.news.aol.com> w8jitom@aol.com (W8JI Tom) writ es: >In article , n4lq@iglou.com (Steve Ellington) >writes: >>Further, when a line has a mismatch like yours, the swr will appear to >>vary for different lengths of line on any given frequency. > >Not so at all !!! SWR remains constant except for the reduction of SWR >caused by attenuation unless: > >1.) The feedline is improperly installed. >2.) The bridge or line have different design impedances. > >>Sometimes a decent compromise can be achieved by experimenting with >various >short sections of coax added to your feeder. This is real easy on >the higher >>bands where just a short 3ft jumper from the tuner to the rig can make a >>huge different in swr READINGS. > >If changing the length of the 50 ohm line changes the SWR measured by a 50 >ohm VSWR meter, one of the above rules is being broken. Either repair the >meter, buy a real 50 ohm line, re-route the feedline as it leaves the >antenna, or de-couple the feedline with a choke balun. Something is very >wrong, OTHER than line matching or SWR". 73 Tom Tom's exactly right. However, changing the coax length *can* result in an impedance presented to your tuner that's easier to match, IE the coax is acting as a transmission line transformer, and varying distances around the Smith chart will be capacitive, inductive, etc, so you may be able to find something your tuner likes better by experimenting with feeder length. That won't change the VSWR on the line, but as Tom noted, it takes quite a lot of line loss to make the additional loss from VSWR on the feeder significant. Gary -- Gary Coffman KE4ZV | You make it, | Due to provider problems Destructive Testing Systems | we break it. | with previous uucp address es 534 Shannon Way | Guaranteed! | Email to ke4zv@radio.org Lawrenceville, GA 30244 | | From lwbyppp@epix.net Sun Mar 24 17:21:18 1996 From: jackheller Newsgroups: rec.radio.amateur.antenna Subject: Re: GAMMA-MATCH FOR 2M YAGI Date: Thu, 21 Mar 1996 15:05:34 -0800 Message-ID: <3151E0BE.7278@sierra.net> References: <4ih96m$665@suba01.suba.com> George P. Thomas, Jr. wrote: > > Does anyone have or know where I can find DETAILS regarding building a > gamma-match for a 3 element 2m yagi? Thank You and 73's...KB0QVT George, That sounded like a simple request. I looked around and I can see why you asked. I did not find specific dimensions, but in the ARRL Antenna book, there is instructions for "Calculating Gamma Dimensions." Then I looked at the 4 ele. I have down and you may be interested in the dimensions. Stub is 8" long and 3/8" diameter. The shorting clip is placed at 5 1/4" from the feed point. Something for starters. 73 Jack KB7NO From lwbyppp@epix.net Sun Mar 24 17:21:19 1996 From: c002@Lehigh.EDU Newsgroups: rec.radio.amateur.antenna Subject: HARDLINE CUT LENGTH! Date: 22 Mar 1996 18:30:34 -0500 Message-ID: <4ivd6q$1ib3@ns5-1.CC.Lehigh.EDU> maybe with the topic in all caps, someone will read it :) anyway, i have 3/4" 75 ohm hardline obtianed from the local tv CO. i would like it to have good SWR's and low loss...i can either waste 70$ on connectors, or cut it to the 146mhz electrical length. i've heard of cuting it this way, but i dont know how PLEASE reply! thanks DAvid |-----------------------------------------------------------------------| | David Roseman | c002@lehigh.edu OUTTA ORDER! | SysOp of NODE 3 BBS | The Flying HAm - BBS | | | Running OBV/2 Software | Technomage - BBS | | | 610.838.2989 | N3SQE/1 - HAm V | | (Parttime system) | N3SQE@Nxxxx.FNxxxx.PA.USA.NA - Packet | |-----My AWESOME home page :) http://www.lehigh.edu/~c002/c002.html-----| From lwbyppp@epix.net Sun Mar 24 17:21:21 1996 From: n7ws@azstarnet.com (Wes Stewart) Newsgroups: rec.radio.amateur.antenna Subject: Re: HARDLINE CUT LENGTH! Date: Sat, 23 Mar 1996 11:08:01 LOCAL Message-ID: References: <4ivd6q$1ib3@ns5-1.CC.Lehigh.EDU> In article <4ivd6q$1ib3@ns5-1.CC.Lehigh.EDU> c002@Lehigh.EDU writes: >From: c002@Lehigh.EDU >Subject: HARDLINE CUT LENGTH! >Date: 22 Mar 1996 18:30:34 -0500 >maybe with the topic in all caps, someone will read it :) >anyway, i have 3/4" 75 ohm hardline obtianed from the local tv CO. >i would like it to have good SWR's and low loss...i can either waste 70$ on >connectors, or cut it to the 146mhz electrical length. i've heard of cuting >it this way, but i dont know how David: Assuming that by "the 146 MHz electrical length", you mean a 1/2 wavelength multiple, you will have a difficult time doing this without some accurate electrical measurement equipment. Also, I don't understand why you believe this alleviates the need for connectors. Even if you knew the velocity factor (which might vary over the length of the cable) reasonably well, cutting a 1/2 wavelength piece won't be too difficult, however, cutting a piece many 1/2 wavelengths long is non-trivial, if you are relying on physical measurements only. Your best options are to: 1) construct matching networks for the 50 to 70 ohm transformations at each end; 2) use a 70 ohm system throughout; 3) use it without any matching and accept the mismatch; 4) if the run isn't extremely long, forget the whole idea. If you select option 1, there have been a number of articles published on ways to do this. YOU must decide whether the results are worth the effort. Regards, Wes -- N7WS From lwbyppp@epix.net Sun Mar 24 17:21:22 1996 From: w8jitom@aol.com (W8JI Tom) Newsgroups: rec.radio.amateur.antenna Subject: Re: Ignorant question: What's a G5RV??? Date: 21 Mar 1996 03:02:54 -0500 Message-ID: <4ir2fe$fqd@newsbf02.news.aol.com> References: In article , Cecil Moore writes: > W8JI has compared half wave dipoles and G5RVs and found the >lower G5RV outperformed the higher half-wave dipole. Actually on 80 and 40 no one could tell the difference between my open wire fed dipole at ~135 feet (matched with a KW Matchbox at the bottom of the 140 ft feeder and brought into the house through 150 feet of 1" diameter 50 ohm line) and my G5RV at 85 ft (fed with 60 feet of RG-8X cable through a choke balun). Since the ladder line fed dipole was such a pain in the @3$%% to keep up (with the feeder blowing in the wind), I replaced it with the G5RV. Now the G5RV is fed with 1/2 inch hardline coming down the tower to a T network. Works great for me. The SWR is still low on 80, 40, and 20. 73 Tom From lwbyppp@epix.net Sun Mar 24 17:21:23 1996 From: John Fleming Newsgroups: rec.radio.amateur.antenna Subject: Re: Ignorant question: What's a G5RV??? Date: Thu, 21 Mar 1996 12:34:15 +0500 Message-ID: <31510677.7E40@mailbox.mcs.net> References: <314DC5B9.588F@vertex.ucls.uchicago.edu> <4imi61$4dp@fcnews.fc.hp.com> Check out the Antennas West article on it. http://www.far.net/antennaswest John N9NDH From lwbyppp@epix.net Sun Mar 24 17:21:24 1996 From: Edward Lawrence Newsgroups: rec.radio.amateur.antenna Subject: Re: Ignorant question: What's a G5RV??? Date: 21 Mar 1996 14:46:13 GMT Message-ID: <4irq3l$hqs@fcnews.fc.hp.com> References: <314DC5B9.588F@vertex.ucls.uchicago.edu> <4imi61$4dp@fcnews.fc.hp.com> <4ip9fo$1lo@fcnews.fc.hp.com> Cecil Moore wrote: Some snipped I was also speaking of the whole HF spectrum. The G5RV has gain >over a half-wave dipole on all bands except 80M. Since most antennas are >not over 1/2 wavelength high on 80m, it's hard to tell the difference on >that band. W8JI has compared half wave dipoles and G5RVs and found the >lower G5RV outperformed the higher half-wave dipole. More snipped >73, Cecil, KG7BK, OOTC Cecil, I think we agree that a G5RV is a good antenna! :) And that the basic question has been over answered. I do have one of my own. What is an OOTC? Only been licenced for 32 years, but I don't know this one. From lwbyppp@epix.net Sun Mar 24 17:21:25 1996 From: w8jitom@aol.com (W8JI Tom) Newsgroups: rec.radio.amateur.antenna Subject: Re: Ignorant question: What's a G5RV??? Date: 21 Mar 1996 08:00:13 -0500 Message-ID: <4irjst$quf@newsbf02.news.aol.com> References: <4iqmj5$bg0@newsbf02.news.aol.com> In article <4iqmj5$bg0@newsbf02.news.aol.com>, w8jitom@aol.com (W8JI Tom) writes: > >Common mode load impedance and operating power levels do not cause loss or >heating in the choke balun. The only loss is a very small transmission >line mode loss in the parallel wires (or coax) used to make the balun, and >it is never affected only by the length of the transmission line used to >make the balun. The loss is very small line section in a well designed >choke balun. > > Woops. That should have been "Differential mode load impedance and operating power levels" that don't cause loss in the core........ 73 Tom From lwbyppp@epix.net Sun Mar 24 17:21:26 1996 From: w8jitom@aol.com (W8JI Tom) Newsgroups: rec.radio.amateur.antenna Subject: Re: Ignorant question: What's a G5RV??? Date: 22 Mar 1996 09:47:56 -0500 Message-ID: <4iueis$qed@newsbf02.news.aol.com> References: <19960322.094220.22@southlin.demon.co.uk> Hi Graham, In article <19960322.094220.22@southlin.demon.co.uk>, graham@southlin.demon.co.uk (Graham Seale) writes: > >I have since come across G5RVs often, and have always been disappointed. >Usually I can hear stations I cannot work. On 80m it behaves like any >low dipole. That's cause it IS a low dipole. My G5RV is up 130 ft now, it behaves like a high dipole! >The signal goes straight up and comes down all over Europe >(from UK @ 12metres high). My signal goes out and lands all over Europe also, I have the same problem from the SE USA. >Any DX is a real struggle unless you work somebody off the vertically >polarised feeder radiation. The variety that uses 75 ohm coax seems prone >to feature in TV/RFI problems. That's why a choke balun helps. But then, I use one on regular dipoles also. So far as feeder radiation, the G5RV is NO WORSE than feeding a regular dipole with coax and no balun! >Now that I know all the most useful highest current nodes are usually >somewhere inside the balanced feeder part, doing a fine job of cancelling >each other, I won't use it again. It's not really all that bad, and that only applies to 80 meters anyway! Of course it would be better on 80 if it were loaded with a lumped inductor, but look at how blissfully happy people are with antennas like KLM beams. Those antennas are loaded by folded lines carring out of phase currents! It's called linear loading in those antennas, and people LOVE it. In a G5RV the same basic function is called a lossy "mistake", and people HATE it. I find it fascinating technical "reasonings" used to critique the G5RV exist in other antennas, but no one ever mentions them in other applications! To the contrary, the same electrical functions that are blamed for poor G5RV performance are touted as advantages in other antennas! Talk about prejudicial technical analysis! Examples? I don't hear many compliants about dipoles or loops close to the ground being poor low angle radiators (and with no ground screen poor high angle radiators), yet they certainly are. I don't hear belly-aching about the efficiency of linear or stub loaded antennas manufactured by KLM, Uni-hat, Hygain, and others; but the efficiency problems are the same as in the stub of the G5RV! I don't hear whining about feedline radiation in beams, dipoles, and EVEN verticals (with poor grounds), but without a proper choke balun those antennas (yes, EVEN the vertical) have the same problem! 73, Tom From lwbyppp@epix.net Sun Mar 24 17:21:28 1996 From: Edward Lawrence Newsgroups: rec.radio.amateur.antenna Subject: Re: Ignorant question: What's a G5RV??? Date: 20 Mar 1996 15:50:16 GMT Message-ID: <4ip9fo$1lo@fcnews.fc.hp.com> References: <314DC5B9.588F@vertex.ucls.uchicago.edu> <4imi61$4dp@fcnews.fc.hp.com> Cecil Moore wrote: >Edward Lawrence writes: > >>for what it takes to bulid. I like them, but a full length dipole for each >>band >>will get out far better. (If you have the space.) I am now in an apartment, > >You're likely to get some arguments from that statement. For instance, on >17m, the G5RV has 4 lobes each with 10dbi gain over ground while a 17m >dipole has two lobes each with 7dbi gain over ground. In addition, the >G5RV has a lower take-off angle than the dipole. The dipole will not get >out as well as a G5RV on 17m. Where did your "far better" opinion come from? > >73, Cecil, KG7BK, OOTC Cecil, I was speaking in of the whole HF spectrum. And as a general rule, wha t I said was correct. Since the lobing of a long wire is known to be a factor, then I don't feel that my statement was mis-leading. The lobes cause deep nulls between them, as well as the increased strength at the lobe. A dipole has a single broad node with a very narrow null off the end. And, since you mention gain over isotropic, why did you not mention the gain of a simple dipole over isotropic? My references state that antenna height is wha t determines 'take-off angle' for simple wire antennas. Gain reffered to a dipole is the much more appropriate reference point. It all depends on how you are going to use it, dosen't it? If you want gain and controlled directivity, use a beam! If you want a simple wire multi-band antenna, then a G5RV or one of its variants is perhaps a good choice. From lwbyppp@epix.net Sun Mar 24 17:21:29 1996 From: Cecil Moore Newsgroups: rec.radio.amateur.antenna Subject: Re: Ignorant question: What's a G5RV??? Date: Wed, 20 Mar 96 21:02:48 -0500 Message-ID: References: <314DC5B9.588F@vertex.ucls.uchicago.edu> <4imi61$4dp@fcnews.fc.hp.com> <4ip9fo$1lo@fcnews.fc.hp.com> Edward Lawrence writes: >Cecil, I was speaking in of the whole HF spectrum. And as a general rule, wh at Hi Edward, I was also speaking of the whole HF spectrum. The G5RV has gain over a half-wave dipole on all bands except 80M. Since most antennas are not over 1/2 wavelength high on 80m, it's hard to tell the difference on that band. W8JI has compared half wave dipoles and G5RVs and found the lower G5RV outperformed the higher half-wave dipole. >since you mention gain over isotropic, why did you not mention the gain of a >simple dipole over isotropic? My references state that antenna height is wh at I did... I did. I said the 17M halfwave dipole had a gain of 7dbi. But I dis- remembered. EZNEC says 5dbi for the halfwave dipole and 8dbi for the G5RV. So the G5RV is about 3dbd on 17m. Two lobes at 0dbd for a halfwave dipole on 17M and four lobes at 3dbd for a G5RV on 17M. That's 12db! ;-) <==Joke! Joke! 73, Cecil, KG7BK, OOTC From lwbyppp@epix.net Sun Mar 24 17:21:30 1996 From: kame0002@gold.tc.umn.edu (Ahmed M Kamel) Newsgroups: rec.radio.amateur.antenna Subject: Interference pattersn Date: 20 Mar 1996 23:29:26 -0600 Message-ID: Hello. CAn anyone suggest a program or algorithm to calculate interference pattern of 2+ antennas given the infdividual patterns? Thanks kame0002@gold.tc.umn.edu From lwbyppp@epix.net Sun Mar 24 17:21:31 1996 From: k0wa@southwind.net (Lee Buller) Newsgroups: rec.radio.amateur.antenna Subject: loop antennas Date: 21 Mar 1996 22:35:08 GMT Message-ID: <4islis$i4i@opal.southwind.net> Hey, has anyone out there have any experience with loop antennas for the HF bands? I had a delta loop several years ago on 40 meters and it was a good antenna. Is anyone using loops on the new WARC bands? Thanks for any feedback Lee Buller k0wa@southwind.net From lwbyppp@epix.net Sun Mar 24 17:21:31 1996 From: mreising@aol.com (MREISING) Newsgroups: rec.radio.amateur.antenna Subject: Re: Mfgrs of 5 ft Stainless Steel Whips? Date: 22 Mar 1996 08:56:01 -0500 Message-ID: <4iubhh$pnh@newsbf02.news.aol.com> References: <4itcgt$i69@newsbf02.news.aol.com> Reply-To: mreising@aol.com (MREISING) Just go to Radio Shack or any CB dealer and get a 102" ss whip and shorten it. You can cut it using a grinder or file to notch the wip and then snap it off in a vise. (Be sure to wear safety glasses when doing this). 73 de mark, wb9bvv From lwbyppp@epix.net Sun Mar 24 17:21:33 1996 From: dcowey@cyberia.com (gudmundur) Newsgroups: rec.radio.amateur.antenna Subject: MFJ-1786 Hi Q LOOP questions Date: 23 Mar 1996 01:37:42 GMT Message-ID: <4ivkl6$1pt@crash.microserve.net> Hello all from KD3SH, Bought an mfj hq loop and used it once in the vertical mode (loop standing up and raised 10 ft above pavement) worked florida, me with 100 watts pep, them with 1000w pep. Their sig was 10-20 over 9 and my sig was S8 at their end. (14.250 mhz at 10 PM EST). Here's my questions. What has been your experience with the antenna and how does it compare to other small antennas. How does it compare to the AEA unit. And finally, the book says never go beyond 150 watts through the control head. At what point power wise will it blow up? Say with a reasonable VSWR of 2:1 or less, will it take 400w pep or 300vpp at 14 mhz. What if I tune it, remove the control box at my end of the coax and then place the coax direct into 400w transceiver and go to full power. I know this sounds like a dumb CB'er question, but I am serious. I want to use this antenna on field day, and I have added some touches to a Yaesu 747 to produce 400w cw or 400w pep ssb. Yes, you need big batteries and heavy cable to get that kind of power, and the original back panel power connector will become a flaming mess if not replaced with something more substantial. 73 KD3SH Don From lwbyppp@epix.net Sun Mar 24 17:21:34 1996 From: jeff@sec.sel.sony.com (Jeff Kashinsky) Newsgroups: rec.radio.amateur.antenna Subject: Re: Mobile Antenna Spacing Date: 20 Mar 1996 18:10:07 GMT Message-ID: <4iphlv$phg@usenet1.sjc.in.sel.sony.com> References: <1996Mar18.165015.1244@picker.com> <31502420.15C5@csg.mot.com> Reply-To: jeff@sec.sel.sony.com Everyone seems to miss something here! LLoyd can only use one band at a time. The FT-736 will not allow 6 and 2 meter operation simultaneously. I have not looked at the schematic for the 736 but the various rf inputs are probably protected from overload (burnout) as a matter of design. Jeff In article <31502420.15C5@csg.mot.com>, Paul Moller writes: |> lloyd korb wrote: |> > |> > I plan on running my Yaesu FT-736R from my van. I can space the 6 |> > & 2 mtr antennas about 8 feet apart on the roof. I'm concerned that |> > the close proximity of the two antennas will cause excessive RF to |> > the receiver front ends. Does anyone have experience with a similar |> > installation? |> > |> > 73, Lloyd K8DIO |> > |> > KORB@XRAYMKT.PICKER.COM |> |> A good rule of thumb is that two dipoles will have 30dB of coupling loss |> when exactly aligned with each other, and spaced by 1 wavelength, and in |> free space. From there out it goes as 6dB/octave distance in free space. |> On the roof of a vehicle there are many other factors such as edges of |> the roof which can change the coupling of ground plane antennas due to |> ground currents, etc. |> |> I like to figure that another receiver should get no more than +10 dBm |> into it from a nearby transmitter. This is from a "safety" viewpoint. |> However at +10dBm many recievers will be in saturation. If you can keep |> the level to 0dBm (or even lower)that would be better. |> |> Remember that when one radio transmits and the other receiver |> (temporarily) goes quiet/dead, there are two likely causes. |> 1) Excessive incoming signal strength causing gain reduction in the |> receiver, thus showing up as bad sensitivity. and |> 2) Noise in the RX band coming out of the transmitter of the first |> radio. This can easily be as high as 40-50 dB over thermal for a |> comercial radio, and is likely higher for a ham rig. That is why a |> repeater needs a duplexer with 70 or more dB of isolation. |> |> In summary, shoot for the 10dBm rule, and learn to live with the |> desense. |> |> Paul_Moller@csg.mot.com -- Jeff WU2A/6 reply to: jeff@sec.sel.sony.com phone: (408) 955-4116 From lwbyppp@epix.net Sun Mar 24 17:21:35 1996 From: clang@traveller.com (Curtis Langston) Newsgroups: rec.radio.amateur.antenna Subject: New J-pole lengths (apt. antenna) Date: 21 Mar 1996 06:07:38 GMT Distribution: inet Message-ID: <4iqrna$e4a@tsunami.traveller.com> Reply-To: ????@???.???????.??? I have found the lengths given in several articles for the 300 ohm twin lead J-pole antenna (VHF) to be too long. By using a Bird thru-line wattmeter with a 2.5 watt slug,I found the SWR to be too high. The following lengths gave a very low SWR and good results on both 2meter and 440 bands. |o| do not short this end. start with a 50" piece _ _ | | of twin lead,assemble bottom first,measure from | | | coax solder points for the 47 1/4" & 16 1/4" | | | lengths,trim the wires leaving center plastic | | | to make a small hole to hang with string or | | | fishing line. | | | | | | | | 47 1/4" | | | | | | | | | <== 1/4" gap | | _ _ | | | | | | | | | | | 16 1/4" | | | | | | | | __|__ | | _|_ coax ctr. cond.==> * * <== coax shield to "gap" side ----- | | 1 1/2"==> | | ----- -*- <== strip 1/8",fold wires together & solder After soldering coax to points, make three 1" to 2" turns in coax and tape together, this will prevent the coax from "radiating". Use at least 72" of coax,(I found 72" or 95" works well). (RG 58/U) **** DO NOT use foam twin lead, use only 300 ohm "FLAT" twin lead **** If you have a wattmeter or swr bridge you can "trim" the top for lowest SWR, but I found these lengths best for 145 to 147 mhz (also good on 440) Send me a note & tell me how it works, 73 KF4FVH From lwbyppp@epix.net Sun Mar 24 17:21:36 1996 From: dbwillia@uci.edu (Brian Williams) Newsgroups: rec.radio.amateur.antenna Subject: Re: Paint on a Vertical Date: 17 Mar 1996 15:16:28 GMT Message-ID: <4ihacc$r3v@news.service.uci.edu> References: In article , bb840@scn.org says... >I'm about to move into a development with the usual antenna >restrictions. Just wondered if anyone has had any luck applying >a coat of dark colored paint to a vertical? I realize the paint >would have to be a non-metalic type. You don't have to paint the metal antenna with a non-metalic paint! Just like wire with insulation, you'll just have to allow for the velocity factor (in other words mistuning the antenna) at least to a small degree. Go ahead and use a metalic paint. Brian From lwbyppp@epix.net Sun Mar 24 17:21:37 1996 From: Gerald Schmitt Newsgroups: rec.radio.amateur.antenna Subject: Re: Question, where can I find ..... Date: Thu, 21 Mar 1996 12:22:27 -0700 Message-ID: <3151AC73.5C4E@ix.netcom.com> References: <31500063.1BA4@fast.net> Jay wrote: > Can anyone suggest where I might be able to buy a piece of hardware used > for anchoring guy wires call an "Earth Screw"? It kinda looks like an > auger that can be turned into the ground with an eyeloop on the end Go to a pet store. They sell them to tie your dog to. Also they are sold in sets of three for more money to tie your airplane to the ground at aircraft supply houses. I have a bunch they are great for field day. 73 de3 Jerry From lwbyppp@epix.net Sun Mar 24 17:21:38 1996 From: w8jitom@aol.com (W8JI Tom) Newsgroups: rec.radio.amateur.antenna Subject: Re: Question, where can I find ..... Date: 21 Mar 1996 13:48:04 -0500 Message-ID: <4is894$473@newsbf02.news.aol.com> References: <4irtac$e1o@dawn.mmm.com> >>Can anyone suggest where I might be able to buy a piece of hardware used >>for anchoring guy wires call an "Earth Screw"? It kinda looks like an >>auger that can be turned into the ground with an eyeloop on the end for >>attaching guy wires to. > >>Tnx in advance for any suggestions etc... > >>Jay n2mga@fast.net > I buy my parts direct from Cable TV equipment suppliers. The prices I paid last year were: 1/4 inch EHS guy strand ......$ 8 per 100 feet 6 foot long screw type guy anchors........7.92 each guy grips....................$0 .79 each guy insulators ..........$2.50 each Try the Yellow Pages first. 73 Tom From lwbyppp@epix.net Sun Mar 24 17:21:39 1996 From: chideste@xvnews.unconfigured.domain (Dale Chidester) Newsgroups: rec.radio.amateur.antenna Subject: Re: Question, where can I find ..... Date: 22 Mar 1996 16:05:11 GMT Message-ID: <4iuj3n$9bv@igate2.pt.cyanamid.com> References: <31500063.1BA4@fast.net> Reply-To: chideste@xvnews.unconfigured.domain Jay, You might try a house trailer/ mobile home center. They sometimes use them to anchor trailers to the ground against high winds. 73, Dale In article 1BA4@fast.net, Jay writes: >Can anyone suggest where I might be able to buy a piece of hardware used >for anchoring guy wires call an "Earth Screw"? It kinda looks like an >auger that can be turned into the ground with an eyeloop on the end for >attaching guy wires to. > >Tnx in advance for any suggestions etc... > >Jay n2mga@fast.net From lwbyppp@epix.net Sun Mar 24 17:21:40 1996 From: rikoski@niia.net (Rick Rikoski) Newsgroups: rec.radio.amateur.antenna Subject: Re: Question, where can I find ..... Date: Thu, 21 Mar 1996 08:20:15 -0500 Message-ID: References: <31500063.1BA4@fast.net> In article <31500063.1BA4@fast.net>, Jay wrote: > Can anyone suggest where I might be able to buy a piece of hardware used > for anchoring guy wires call an "Earth Screw"? It kinda looks like an > auger that can be turned into the ground with an eyeloop on the end for > attaching guy wires to. > > Tnx in advance for any suggestions etc... > > Jay n2mga@fast.net ===================================== Uh well Jay your neighborhood pet store probably has some pretty substantial screw anchors for leashing dogs to one's back yard. If its solid enough to hold a Rottwiler (a dynamic load).Three or four of em should be able to anchor your antenna guys. Tae a look anyway. -- Rick Rikoski Chicago/Indiana Dunes rikoski@niia.net From lwbyppp@epix.net Sun Mar 24 17:21:41 1996 From: soniat@prism.gatech.edu (Edward Soniat du Fossat Jr) Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.equipment Subject: Seeking Power mobile antenna raise/lower mounting. Date: 22 Mar 1996 15:14:18 -0500 Distribution: usa Message-ID: <4iv1mq$n4a@acmey.gatech.edu> I am looking for a way to be able to lower my antenna so that I can garage my car. I need power because it is very difficult to reach the mounting with out climbing on the seats. Since I am forced to ware a rediculous costume consisting of an expensive wool jacket, silk tie and coton shirt every day climbing up on the roof is not a good option. If I could just flip a switch on the dash it would be perfect. Can anybody recommend one and know where I can find it. I've ordered a bunch of catalogs but I haven't seen one yet. Thank you. Ed -- _| | _ Edward C. Soniat KE4TFT Internet:ed@pobox.com _| -|_ Mass transfer: 1854 Bishop's Green Dr | | Marietta GA 30062-6079 (770)579-3279 From lwbyppp@epix.net Sun Mar 24 17:21:42 1996 From: (Gary) turtle@wwa.com Newsgroups: rec.radio.amateur.antenna Subject: Re: Shit, my FM-25 is Fucked! What to do?? Date: 21 Mar 1996 11:47:29 GMT Message-ID: <4irfkh$fg4@kirin.wwa.com> References: <314C74DA.2BB3@shadow.net> I just have one thing to say _ . _ _ . _ _ _ . _ _ _ , _ . _ _ _ _ . . . "73" Gary KF9CM From lwbyppp@epix.net Sun Mar 24 17:21:43 1996 From: billhar@spaceworks.com (bill harris) Newsgroups: alt.radio.scanner,alt.radio.pirate,aus.radio,rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc,rec.radio.scanner,rec.radio.shortwave,uk.radio.amateur Subject: Re: Shit, my FM-25 is Fucked! What to do?? Date: 21 Mar 1996 11:06:45 -0500 Message-ID: <4iruql$66n@mars.spaceworks.com> References: <314C74DA.2BB3@shadow.net> >so i started touching the underside of the PCB, where all the >soddering connections are. If you tried soldering the connections instead of soddering them they might work. From lwbyppp@epix.net Sun Mar 24 17:21:44 1996 From: Ray Woodward Newsgroups: alt.radio.scanner,alt.radio.pirate,aus.radio,rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc,rec.radio.scanner,rec.radio.shortwave,uk.radio.amateur Subject: Re: Shit, my FM-25 is Fucked! What to do?? Date: Wed, 20 Mar 1996 18:21:05 +0000 Distribution: world Message-ID: References: <314C74DA.2BB3@shadow.net> <4imv4v$45o@cloner2.ix.netcom.com> In article <4imv4v$45o@cloner2.ix.netcom.com>, Horney Byte comments : >FUCKED!!!!!!! > >Open your ASS and I will FUCK YOU!!!!! > >Pervert & Dirty Mouth....... > >Horney Bite The really sad thing is that excrement like that get to vote ..:-( -- Ray /////\\ ( # # ) -----oOO-(_)-OOo----------------------------------------------------- ++++ My WWW page: http://homepages.enterprise.net/raywoodward/ ++++ --------------------------------------------------------------------- [raywoodward@enterprise.net] From lwbyppp@epix.net Sun Mar 24 17:21:45 1996 From: Francis Lyn Newsgroups: alt.radio.scanner,alt.radio.pirate,aus.radio,rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc,rec.radio.scanner,rec.radio.shortwave,uk.radio.amateur Subject: Re: Shit, my FM-25 is Fucked! What to do?? Date: 21 Mar 1996 12:44:13 GMT Message-ID: <4iriut$84k@shpk1.candu.aecl.ca> References: <314C74DA.2BB3@shadow.net> <31507c6b.7821493@news.demon.co.uk> Try a soap and water mouthwash; It worked for me when I was a kid! From lwbyppp@epix.net Sun Mar 24 17:21:46 1996 From: mitch@primenet.com (mlmitchell) Newsgroups: alt.radio.scanner,alt.radio.pirate,aus.radio,rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc,rec.radio.scanner,rec.radio.shortwave,uk.radio.amateur Subject: Re: Shit, my FM-25 is Fucked! What to do?? Date: 21 Mar 1996 17:18:02 -0700 Message-ID: <3151e300.15725627@news.primenet.com> References: <314C74DA.2BB3@shadow.net> Reply-To: mitch@primenet.com cRiTTa66 wrote: >ok, heres the story, >A friend and i built the "FM-25" yesterday. We turned it on and >nothing.. So we looked at the troubleshooting guide, "check all the >capacatators for correct poplaraty" so well what do you know i fucked up >on C4. So i re did c4 which is a 10uF ec. tried it again, it worked! >After a little while of use (1 hour) is just stoped. no nothing, just >static. I was prety MAD. So i took a lot at the PCB, it looked fine, no >bridges or anything. My friend lookd at it and held it in her hand.. It >suddnelt worked again. After this i set it up again to play some music >from my walkman while listinging from my stero system in my room. after >the fm-25 stoped working again is was ovious something is really fucked >up with it.. but it was geting late and she had to go home. So today i >was resoddering all the parts to see if i could fix the problem... >It works again. Ok this is good, then it fucked up again! Dam i was >pissed. so i started touching the underside of the PCB, where all the >soddering connections are. it still wasnet working. Even though the >light for "freqency LOCK" was on the transmiter wan't working. before >the led would just be off. > >i also have this problem geting stero on the fm-25 before the unit >completly broke. any ideas? > >Well im having trouble , should i send it in to be repaired for $36? >Or just send in the BA1404 and the program IC's to see if there fucked >up? i dono. well if you have any suggestions please e-mail me at >critta66@shadow.net. > >Thanx in advance > >PS i can be reached on IRC (undernet) on #god or #troy I hope that you DO NOT use such foul language while talking on the FM-25 if and when you get it working. Bill From lwbyppp@epix.net Sun Mar 24 17:21:47 1996 From: Brunob@glo.be (Bruno Beckers) Newsgroups: rec.radio.amateur.antenna Subject: Re: Shit, my FM-25 is Fucked! What to do?? Date: Mon, 18 Mar 1996 23:04:42 GMT Message-ID: <4iku4u$oj0@rhea.glo.be> References: <314C74DA.2BB3@shadow.net> First of all, try to use decent english Bruno Beckers Brunob@glo.be From lwbyppp@epix.net Sun Mar 24 17:21:48 1996 From: jlundgre@delta1.deltanet.com (John Lundgren) Newsgroups: alt.radio.scanner,alt.radio.pirate,aus.radio,rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc,rec.radio.scanner,rec.radio.shortwave,uk.radio.amateur Subject: Re: Shit, my FM-25 is Fucked! What to do?? Date: 21 Mar 1996 02:51:56 GMT Message-ID: <4iqg8c$s02@news02.deltanet.com> References: <314C74DA.2BB3@shadow.net> <4ijvsq$5ud@postman.jet.uk> <4imtsp$j8j@btc1.up.net> Roland Burgan (rburgan@up.net) penned: : If this fellows kitmaking skills are of the same caliber as : his language, I can see why his kits don't function properly. AMEN! -- From lwbyppp@epix.net Sun Mar 24 17:21:49 1996 From: otheral@ix.netcom.com(Al Williams ) Newsgroups: rec.radio.amateur.antenna Subject: Re: Shit, my FM-25 is Fucked! What to do?? Date: 22 Mar 1996 02:29:27 GMT Message-ID: <4it3a7$q7i@dfw-ixnews3.ix.netcom.com> References: <314C74DA.2BB3@shadow.net> <31507c6b.7821493@news.demon.co.uk> <4iriut$84k@shpk1.candu.aecl.ca> In <4iriut$84k@shpk1.candu.aecl.ca> Francis Lyn writes: > >Try a soap and water mouthwash; It worked for me when I was a kid! > I'm sure the rest of the net all the cross posted dribble on this thread. From lwbyppp@epix.net Sun Mar 24 17:21:50 1996 From: Gary - KJ6Q Newsgroups: alt.radio.scanner,alt.radio.pirate,aus.radio,rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc,rec.radio.scanner,rec.radio.shortwave,uk.radio.amateur Subject: Re: Shit, my FM-25 is Fucked! What to do?? Date: 24 Mar 1996 02:01:35 GMT Message-ID: <4j2adv$a6b@miwok.nbn.com> References: <314C74DA.2BB3@shadow.net> <4iruql$66n@mars.spaceworks.com> <4itlar$3pd@tube.news.pipex.net> <31548C17.6F65B43E@sinister.com> Doctor Who wrote: >You people are a bunch of pretentious old farts. So the guy gets a >little frustrated and says he accidently FUCKED UP his transmitter. Big >deal. That's the way alot of people really talk. The Internet is a >common meeting place, that is not censored (at least not yet) and if you >are going to get so bent out of shape over a little bit of profanity, >you are not going to be able to reap the advantages of the net. So get >real, okay? He's not really that bad... > >-----------=?> Doctor Who References: <314D7CC8.7EAB@vertex.ucls.uchicago.edu> In article <314D7CC8.7EAB@vertex.ucls.uchicago.edu>, Lisa Kohn wrote: >I know this is a stupid question, but I can't seem to find a good >answer. What is the difference between balanced voltage and balanced >current?? Thanks Since I coined the terms "voltage balun" and "current balun" to make the distinction, guess I need to give this a shot. "Balanced voltage" means that the voltages at two points are equal and opposite relative to some reference. In regard to a balun, "balanced voltage" is achieved when the voltages at the two balun output terminals are equal and opposite each other with respect to the "cold" terminal of the balun's input. That is, if we call the "cold" input terminal the reference, or zero volts, and find that the voltage at one of the output terminals is + 1 volt at a given instant, then the voltage at the other output terminal is -1 volt at the same instant. "Balanced current" means that the currents on two conductors are equal and opposite. That is, if the current in one conductor is + 1 ampere at a given instant, the current in the other conductor (measured directly adjacent to the first measurement) is -1 ampere. When current balance is achieved on a coaxial cable, all the current is inside the cable; when unbalanced, some current flows on the outside. Current and voltage balance occur simultaneously only if the impedances from both terminals to the reference are equal. Roy Lewallen, W7EL From lwbyppp@epix.net Sun Mar 24 17:21:53 1996 From: w8jitom@aol.com (W8JI Tom) Newsgroups: rec.radio.amateur.antenna Subject: Re: Sturba Curtain Date: 20 Mar 1996 02:01:54 -0500 Message-ID: <4ioah2$h4p@newsbf02.news.aol.com> References: In article , rikoski@niia.net (Rick Rikoski) writes: >I'm fascinated with the idea of building a couple of Sturba curtains for >UHF and also VHF (2 separate antennas) tv reception. > >Can they be made broadband enough? Suggested design dimensions? General >comments? > >For you old timers: wasn't there a 4 stack antenna sold and quite popular >in the "50's in the US for VHF tv that looked like a Sturba? Help me out >here. Was it a Sturba? Anybody remember details? Hi Rick, I've built some Sterbas in the past. Bandwidth is not good, mainly because of phase shift accumulation as current moves through the elements. The array works better if it is fed near the center, current distribution is more even. Sterbas are single band (or part of a band) antennas! They are one of the most "difficult to tune" curtain antennas, since the elements are series fed (in a closed RF loop). A better curtain array can be made with an arrangement of dipoles with screen reflectors. These types of arrays are used at VOA and other short wave BC stations, and have more gain than much larger Rhombics. This is probably the type of antenna you are remembering from old TV antennas. The dipole with reflector array (aka USIA Curtain, CIA Curtain, etc) is a combination of broadside and collinear elements with a screen or wire reflector. Gain is very high, performance is good over at least 2.5 : 1 frequency range with careful design of dipole elements, and over wider ranges with interlaced or stub decoupled elements. This type of antenna uses a tiny portion of a Rhombic's required area, and has much higher gain and F/B ratio. 73 Tom From lwbyppp@epix.net Sun Mar 24 17:21:54 1996 From: rikoski@niia.net (Rick Rikoski) Newsgroups: rec.radio.amateur.antenna Subject: Re: Sturba Curtain Date: Thu, 21 Mar 1996 08:15:31 -0500 Message-ID: References: <4io4i3$e1h@news.tamu.edu> In article <4io4i3$e1h@news.tamu.edu>, mluther@tamu.edu wrote: > In , rikoski@niia.net (Rick Rikoski) writes: > >I'm fascinated with the idea of building a couple of Sturba curtains for > >UHF and also VHF (2 separate antennas) tv reception. > > > >Can they be made broadband enough? Suggested design dimensions? General > >comments? > > > >For you old timers: wasn't there a 4 stack antenna sold and quite popular > >in the "50's in the US for VHF tv that looked like a Sturba? Help me out > >here. Was it a Sturba? Anybody remember details? > > > >-- > >Rick Rikoski > >Chicago/Indiana Dunes > >rikoski@niia.net > > Finey (Sic?) Corporation made them and they were known in the trade as a > colinear array. I know where there is STILL one of them up that is still > standing in Bryan, Texas on a TV mast over in the west side of town. > > I have NO idea what would happen if I tried to buy it or whatever, but, lo, > all these years later is is STILL pointed at where our first television station > came from 100 miles away, channel TWO in Houston. > > Now THAT was a REAL TVI challenge...! > > Mike W5WQN as a guest @leviathan.tamu.edu (no mail address there...) ================================== Ah yes, Finco colinear array! thank you. I know of two of them, both in South Bend aimed toward Chicago 90 miles away. Channels 2, 5, 7, 9, 11 all at 1400 feet above sea level on the Sears or Hancock buildings and well below the horizon at South Bend. Do you remember whether this antenna had any UHF response? Is Finco still in business? (I think I like antennas like this one because they provide spacial diversity whereas a log periodic or wideband yagi doesn't) -- Rick Rikoski Chicago/Indiana Dunes rikoski@niia.net From lwbyppp@epix.net Sun Mar 24 17:21:55 1996 From: Dave Heil Newsgroups: rec.radio.amateur.antenna Subject: Re: Sturba Curtain Date: Fri, 22 Mar 1996 16:03:54 +0000 Message-ID: <3152CF6A.1FBE@clinet.fi> References: Rick Rikoski wrote: > > I'm fascinated with the idea of building a couple of Sturba curtains for.... (snip) It's STERBA Dave OH2/K8MN > From lwbyppp@epix.net Sun Mar 24 17:21:56 1996 From: seaman@cleo.murdoch.edu.au Newsgroups: rec.radio.amateur.antenna Subject: Re: Super J-Pole antenna Date: Fri, 22 Mar 96 22:10:25 Message-ID: <4iucmf$8op@newsman.murdoch.edu.au> References: <4ho8js$881@ns1.thpl.lib.fl.us> <4i9bdi$p6o@news1.inlink.com> Gary, I tried to access your homepage to have a look at your j-poles & data. They c ouldn't be accessed from this part of the world... Are they still on line or could there be a pro blem this end? Please reply via e-mail (I don't check in here regularly) Regards, Rob... seaman@cleo.murdoch.edu.au From lwbyppp@epix.net Sun Mar 24 17:21:57 1996 From: graham@southlin.demon.co.uk (Graham Seale) Newsgroups: rec.radio.amateur.antenna Subject: The FM-25 flame - apology Date: Wed, 20 Mar 1996 21:28:32 GMT Distribution: world Message-ID: <19960320.212832.70@southlin.demon.co.uk> Reply-To: graham@southlin.demon.co.uk For all this group. I guess I just got angry and didn't think! It was all very well to let *troy (alias *god) have the benefit of a little choice invective, but it was plain careless of me to not to redirect it. For allowing it to perpetuate under that same rude heading (unmodified!), I am very sorry - and I apologise unreservedly. G4WNT -- Graham Seale From lwbyppp@epix.net Sun Mar 24 17:21:58 1996 From: n7ws@azstarnet.com (Wes Stewart) Newsgroups: rec.radio.amateur.antenna Subject: Re: Tower Guy Spacing Date: Sat, 23 Mar 1996 11:24:00 LOCAL Message-ID: References: <4hpihd$r8i@kelly.iaonline.com> <4i3p1h$a25@firebrick.mindspring.com> In article <4i3p1h$a25@firebrick.mindspring.com> kr4tg@mindspring.com (mike de l pozzo) writes: >From: kr4tg@mindspring.com (mike del pozzo) >Subject: Re: Tower Guy Spacing >Date: Tue, 12 Mar 1996 12:00:45 GMT >kg9cc@iaonline.com (Jim Rowley) wrote: >>Hello all. This is my first time posting so I hope I do it right. >>I remember reading somewhere that if you are limited on space that >>you can reduce the distance from the tower base to guy anchor point >>from the recomended 80% of tower height to something like 50% by >>going to 4 guys spaced 90 degrees. Rohn shows this in their catalog >>but only for the foldover towers. I plan to install 70ft of Rohn 45G >>and would like to space the guy anchors between 35 and 40 ft from the >>base. Anyone out there know about this or has used this method? >>Thanks and 73 >>Jim, KG9CC >Hello Jim, >yup , I have a 70 ft. Rohn 25 W/ a 4 el Quad on top . Previously had >all three Hygain Long Johns on top ( 5 el. 10/15/20 beams). It seems >to be a nice arrangement , especially if ground space is somewhat >limited. My guys are at 90 deg. intervals and located at 20ft , 40ft , >and 65 ft. The material used is of 5/16 dia stranded . The tower has >been hit with better than 70 MPH wind with the beams on top and did >not even budge. I will suggest however that you put some serious work >into the guy anchors ( cement embedded screw anchors or similliar ). >My anchor points are 45 & 50 feet from the base and are the above >arrangement. Gud luck es 73 de >KR4TG ,Mike I'll add my 2 cents worth on here as my newserver has lost the original posting. I am currently installing a Rohn 45 fold-over so I am familiar with the four guy system. I believe that Rohn uses this only because of the need for the guys to be out of the way of the foldover mechanism. There is no added strength in this method. Consider that the wind is blowing on a line that parallels one drawn from a single guy anchor to the tower. The overturning moment is resisted only by the single guy wire/anchor. The other two(or three) guys could be removed without effect. So, in this worst case, there is nothing to be gained by increasing the number of guys. Does worst case actually happen? Maybe not, but I think you should design for it. Good luck, Wes -- N7WS From lwbyppp@epix.net Sun Mar 24 17:21:59 1996 Newsgroups: rec.radio.amateur.antenna From: n4lq@iglou.com (Steve Ellington) Subject: Tribander trap loss? Message-ID: Date: Sat, 23 Mar 1996 12:53:17 GMT Adds for triband beams promise nearly 6db of gain but how much power is lost in the traps? They usually have at least 6 traps and I'm sure they aren't lossless. I would think this would be of concern when comparing a trap beam to a quad. -- Steve Ellington N4LQ@IGLOU.COM Louisville, Ky From lwbyppp@epix.net Sun Mar 24 17:22:00 1996 From: KI4TZ@sunbelt.net (Joe Barkley) Newsgroups: rec.radio.amateur.antenna Subject: Vhf, Uhf Log Periodic?? Date: Mon, 18 Mar 96 12:50:06 GMT Message-ID: <4ijiqu$lp6@news1.sunbelt.net> Someone mentioned to me there is a 6meter-1.2ghz log periodic on the market. Anyone know of it or had experience with it. I am just getting on 6 meters and want a decent directional antenna and only have roomfor one yagi an top of A-4 hf yagi. Any comments or suggestions would be helpful. Tnx Joe From lwbyppp@epix.net Sun Mar 24 17:22:01 1996 From: egriffin@ctc.net (Ed Griffin) Newsgroups: rec.radio.amateur.antenna Subject: Re: Vhf, Uhf Log Periodic?? Date: Sat, 23 Mar 1996 12:12:47 GMT Message-ID: <4j0q0e$m87@news1.sunbelt.net> References: <4ijiqu$lp6@news1.sunbelt.net> rikoski@niia.net (Rick Rikoski) wrote: >> Someone mentioned to me there is a 6meter-1.2ghz log periodic on the market . >> Anyone know of it or had experience with it. I am just getting on 6 meters and >> want a decent directional antenna and only have roomfor one yagi an top of A-4 >> hf yagi. Any comments or suggestions would be helpful. >> >>================ > > Joe, there is one. It is called the "Create" It think it is made in >Virginia, the land of the CIA. >Costs $300 or $400 bucks. I understand that it has the gain and rejection >qualities of a 4 element yagi-uda on any frequency in this range. Pretty >small too. >I'd be interested in buying one, if I could get a good price. >-- >Rick Rikoski >Chicago/Indiana Dunes >rikoski@niia.net My recomendation is TENNADYNE........a quality product that I'm very pleased with. Contact Chuck Brainard, 123 W. 11 th St., Rockport, TX 78382. Phone is 512-790-7745 He's a good guy to do business with, from my experience. Tell him ' Ed sent ya ' 73 From lwbyppp@epix.net Sun Mar 24 17:22:02 1996 From: jpll@vectorbd.vivanet.com (Jim Lill) Newsgroups: rec.radio.amateur.antenna Subject: Re: Vhf, Uhf Log Periodic?? Date: 20 Mar 1996 19:21:19 GMT Message-ID: <4iplrf$79p@vectorbd.vectorbd.com> References: <4ijiqu$lp6@news1.sunbelt.net> Joe Barkley (KI4TZ@sunbelt.net) wrote: : Someone mentioned to me there is a 6meter-1.2ghz log periodic on the market. : Anyone know of it or had experience with it. I am just getting on 6 meters a nd : want a decent directional antenna and only have roomfor one yagi an top of A -4 : hf yagi. Any comments or suggestions would be helpful. It *IS* made by Create, but is made in Japan, not VA. It is sold by a VA company, EEB. They were in Vienna VA the last I knew. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Jim Lill jpll@vectorbd.com http://www.vectorbd.com/users/jpll/home.html wa2zkd@wb2psi.#wny.usa.na From lwbyppp@epix.net Sun Mar 24 17:22:03 1996 From: jlundgre@delta1.deltanet.com (John Lundgren) Newsgroups: alt.radio.scanner,alt.radio.pirate,rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc,rec.radio.scanner,rec.radio.shortwave,uk.radio.amateur Subject: Re: Weird Radio Problem Date: 21 Mar 1996 02:44:01 GMT Message-ID: <4iqfph$s02@news02.deltanet.com> References: <4imjob$46g@ray.atw.fullfeed.com> Steve Work (slwork@netcom.com) penned: : Dennis Nuetzel (bigd@mail.atw.fullfeed.com) wrote: : : >There is a small, minor detail: Air transmissions were AM, last time I : : >checked! How does an FM receiver with poor-selectivity receive AM : : >transmissions??? : : If close enough, it will. I have picked up CB radio transmissions (Als o : : AM) on a nearby FM reciever. : "AM rejection" is a spec which applies to FM radios. It is worse on : cheaper ones. I'm assuming that by worse, you mean is has poorer AM rejection. : The circuitry used to detect FM signals can respond to changes in the : amplitude. Especially when the circuit is cheap, and under conditions : where it is overloaded. Actually, when the circuitry is overloaded, it should limit and prevent AM from getting thru. Maybe the circuitry is not overloaded enough. ;-) -- #======P=G=P==k=e=y==a=v=a=i=l=a=b=l=e==u=p=o=n==r=e=q=u=e=s=t======# | John Lundgren - Elec Tech - Info Tech Svcs. | jlundgre@ | | Rancho Santiago Community College District | deltanet.com | | 17th St at Bristol \ Santa Ana, CA 92706 | http://rsc.rancho| | My opinions are my own, and not my employer's. | .cc.ca.us | | Most FAQs are available through Thomas Fine's WWW FAQ archive: | |http://www.cis.ohio-state.edu:80/hypertext/faq/usenet/FAQ-List.html| | "You can flame your brains out -- it won't take long." | #===T=u=z=l=a==C=o=m=p=a=n=y=.=.===t=h=r=e=e='=s==L=e==C=r=o=w=d=!==# From lwbyppp@epix.net Sun Mar 24 17:22:04 1996 From: graham@southlin.demon.co.uk (Graham Seale) Newsgroups: rec.radio.amateur.antenna Subject: Wideband Dipoles Date: Fri, 22 Mar 1996 09:03:37 GMT Distribution: world Message-ID: <19960322.090337.87@southlin.demon.co.uk> Reply-To: graham@southlin.demon.co.uk Hello All This is about those small "wideband" dipoles that look like a mess of oversized coat hangers tied together - basically a sparse wire grid spaceframe of a 3D "bowtie". They seem abound in advertisments for EMC test facilities and are probably used in EMC screened chambers, metallised tents, and maybe open field test sites. Assume we already know that expanding a dipole wire into a "cage" has a broadbanding effect, the questions are:- * Are all the "elements" the same length - ie. is it a symmetrical frame? * How wide is the typical bandwidth of these antennas? * How flat is the typical frequency response over the band? * Could such bulbous shapes (scaled down) be usefully placed as the driven element in multielement antennas (YAGIs etc.) ? * Is there any mileage in visualising whole sets of directors all made up of little "multiple coathanger dipole" shapes? -- Graham Seale From lwbyppp@epix.net Sun Mar 24 17:22:05 1996 From: ka_strom@ix.netcom.com(Kevin Alfred Strom) Newsgroups: rec.radio.amateur.antenna Subject: Windmill Towers? Date: 19 Mar 1996 09:58:04 GMT Message-ID: <4im0fc$is9@cloner2.ix.netcom.com> Does anyone have any experience with disassembling / re-erecting windmill towers for antenna supports and/or shunt-fed radiators? They are common here in the Minnesota countryside, and since so many are apparently unused, could probably be acquired cheaply. I like their fat footprint and built-in ladder (some even have a platform near the top) for obvious reasons. But maybe I am overlooking some problems. I am most interested in your thoughts. Thanks -- Kevin WB4AIO in Rochester Minnesota From lwbyppp@epix.net Sun Mar 24 17:22:06 1996 From: kr4tg@mindspring.com (mike del pozzo) Newsgroups: rec.radio.amateur.antenna Subject: Re: wire beams Date: Thu, 21 Mar 1996 11:49:46 GMT Message-ID: <4irfp1$lti@firebrick.mindspring.com> References: wa4pgm@moonstar.COM wrote: >Hello all I would like to build some wire beams between 2 towers here, >possibly trees or poles. Need antennas to work 20-15-10 meters and have >about 100' spacing to play with between towers. >Wonder if some of you could give me any ideas, what worked for you ? >73 Kyle >------------------------------------- >Name: kyle chavis >E-mail: wa4pgm@moonstar.com >Date: 03/19/96 >Time: 10:20:00 >This message was sent by Chameleon >------------------------------------- Hello Kyle, I have built the 3 element inverted Vee array described in ON4UN's Low Band DX'ing book with great success. Not alot of elevation is required with this but 1/3 wave above ground, and it proved to be a great addition to the alluminum farm here. The beam was built for 40 mtrs and directed towards VK with great results. I imagine with 10 / 15 / 20 mtrs the task would be even easier. I guess what you need to figure out is what direction you would like to work , unless it's everywhere. in that case a rotary beam would work much better. GUD LUCK es 73 de KR4TG, Mike From lwbyppp@epix.net Sat Mar 30 14:14:23 1996 From: aga@ssguest.west.sun.com (Tony Angerame - Sun SSE) Newsgroups: rec.radio.amateur.antenna Subject: Re: "Hamstick" dipole troubles Date: 21 Mar 1996 21:49:56 GMT Distribution: world Message-ID: <4isiu4$od2@newsworthy.West.Sun.COM> References: <314D9ACC.6BF7@leps.phys.psu.edu> Reply-To: aga@ssguest.west.sun.com Seems that a 3 to 1 swr with 52 ohm coax feed indicates an impedance of about 17 ohms at the feed point. I'd wind a three to one toroidal transformer if the core wa s handy. Then remeasure the swr to see if it was acceptable i.e less than 2:1. You coul d also try a "hairpin" match. I haven't seen one for a while but the Handbooks should give you an idea. Cut and try never mind that silly engineer stuff. Tony WA6LZH From lwbyppp@epix.net Sat Mar 30 14:14:24 1996 From: Cecil Moore Newsgroups: rec.radio.amateur.antenna Subject: Re: "Hamstick" dipole troubles SOLVED Date: Sat, 23 Mar 96 21:21:23 -0500 Message-ID: References: <4ih53s$aqr@harbour.awod.com> <4j1u55$fkq@inxs.ncren.net> Derrick Cole writes: >Last tip: buy an antenna analyzer. I opted for the MFJ 259. I can't describ e >how handy it's been... Save your money. Use ladder-line and a 20 cent pick up loop and learn exactly the same things about your antenna system that the MFJ259 tells you. I kid you not. Ladder-line is *all* slotted line. Think about it. 73, Cecil, KG7BK, OOTC From lwbyppp@epix.net Sat Mar 30 14:14:25 1996 From: /PN=Scott.C.Werling/O=wallace/PRMD=iadps/ADMD=attmail/C=us/@safe.ia.GOV Newsgroups: rec.radio.amateur.antenna Subject: (none) Date: 28 Mar 96 16:26:14 GMT Message-ID: <199603281626.KAA26577@outpost.safe.ia.gov> >From /PN=Scott.C.Werling/O=wallace/PRMD=iadps/ADMD=attmail/C=us/ Thu Mar 28 1 0:27:17 CST 1996 remote from osiint.safe.ia.gov Date: 28 Mar 1996 10:25:11 -0600 X400-Trace: US*ATTMAIL*IADPS arrival 28 Mar 1996 10:25:11 -0600 action Relayed From: /PN=Scott.C.Werling/O=wallace/PRMD=iadps/ADMD=attmail/C=us/@osiint.safe. ia.gov To: "/RFC-822=Ham-Ant(a)UCSD.EDU/OU=OSI-INTERNET/O=WALLACE/PRMD=IADPS/ADMD=ATT MAIL/C=US/"@osiint.safe.ia.gov In-Reply-To: <"\"/RFC-822=199603251230.EAA21047(a)mail.ucsd.edu/OU=OSI-INTERNE T/O=WALLACE/PRMD=IADPS/ADMD=ATTMAIL/C=US/\""@osiint.safe.ia.gov> Subject: A-B antenna switch Importance: normal Autoforwarded: FALSE Message-Id: P1-Message-Id: US*ATTMAIL*IADPS;IDPS3550 werl0328102246aa UA-Content-Id: werl0328102246aa P1-Content-Type: P2 Priority: normal Received: from osiint.safe.ia.gov by iadpshub.safe.ia.gov; Thu, 28 Mar 1996 10 :27 CST Content-Type: text Content-Length: 820 Question for you: I have 2 antennas (a long wire and G5RV) and 2 hf rigs (HW 9 and a Galaxy V). What I want to do is build or buy a switch of some kind which will handle up to 475 watts (the Galaxy manual sez it will do that much on CW and 300 on SSB) to switch antennas between these 2 rigs. Like an A-B switch for computer printers. Is there such a thing now available ? I am using 450 ohm ladder line on the G5RV and multi-strand wire for the long wire. I am NOT a tech whiz by any means but am interested in building things for my shack. So if a relatively easy-to-build thing would be available from parts, pse advise the HOW TO. Scott N0XZY @ WA0RJT.#EIA.IA.USA.NOAM werling@safe.ia.gov (this one) scott@ia.net (home) www.angelfire.com/free/n0xzy.html (under construction) From lwbyppp@epix.net Sat Mar 30 14:14:26 1996 From: orjan.johansson@kahrs.SE (=?iso-8859-1?Q?=D6rjan_Johanson?=) Newsgroups: rec.radio.amateur.antenna Subject: (none) Date: 30 Mar 96 10:15:56 GMT Message-ID: <01BB1E1B.591F62C0@p4ts1.kalmar.net> add ham-ant From lwbyppp@epix.net Sat Mar 30 14:14:27 1996 From: nick@lansley.demon.co.uk (Nick Lansley G1KZI) Newsgroups: alt.radio.scanner,alt.radio.pirate,aus.radio,rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc,rec.radio.scanner,rec.radio.shortwave,uk.radio.amateur Subject: (removed) Date: Mon, 25 Mar 1996 22:10:36 GMT Message-ID: <827791851.29519@lansley.demon.co.uk> References: <314C74DA.2BB3@shadow.net> <4imv4v$45o@cloner2.ix.netcom.com> <315069A3.5025@ix.netcom.com> Reply-To: nick@lansley.demon.co.uk Please bear in mind that with most news clients, when you reply or comment on an article, the original (complete with offensive words) is included - so anyone doing a search for such stuff for disciplinary investigative reasons could argue YOU sent offensive stuff too. <<< Nick Lansley G1KZI>>> For legal reasons, any messages in this article that reveal I may have taken part in any illegal activity (either directly or indirectly) are hereby disclaimed. I hereby state that I have taken no part in any such activity. ----------------------------------------------------- Home: http://ourworld.compuserve.com/homepages/nicholas_lansley E-mail: nick@lansley.demon.co.uk or G1KZI@lansley.demon.co.uk From lwbyppp@epix.net Sat Mar 30 14:14:28 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: ***help**** with a apt ant Date: Wed, 27 Mar 96 20:28:42 GMT Message-ID: <4jc8pl$lm3@crash.microserve.net> References: <4j2l0k$jin@paperboy.owt.com> reble@ONEWORLD.OWT.COM (steve eizenberg) wrote: >i live on the 4th floor of a 6 floor apt building. i can only put up >an ant on the window a/c unit. the walls are made of concreet and >rebarb, it is an old building built in the 1940's, does someone have >any idea for an ant i can use with my mfj 900 ant tuner? I'm not sure what you mean when you say "on the window a/c unit." Can you run a thin wire out a window and let it hang down the side of the building? If so, you could use your tuner in conjunction with the MFJ Artificial Ground. Some of the RF from the antenna will still be absorbed by the building, but at least you'll get your power to the antenna instead of radiating it from the transmitter itself. If you do this, the rig should also be as close to the point where the antenna exits the building as possible. 73, Jack WB3U From lwbyppp@epix.net Sat Mar 30 14:14:29 1996 From: nrj@cdx.net (Rob M.) Newsgroups: alt.radio.scanner,alt.radio.pirate,aus.radio,rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc,rec.radio.scanner,rec.radio.shortwave,uk.radio.amateur Subject: Re: ...(Heading deleted to protect the innocent) Date: Wed, 27 Mar 1996 04:27:56 GMT Message-ID: <4jaeds$bee@news.bellglobal.com> References: <314C74DA.2BB3@shadow.net> <4imqpg$4cs@daily-planet.execpc.com> <827791846.29519@lansley.demon.co.uk> nick@lansley.demon.co.uk (Nick Lansley G1KZI) wrote: >Karl Kurz wrote: >>Hear, hear..... postings like this make me really excited about >>demonstrating Ham Radio and Newsgroups to my students. >> >I agree - maybe writers of news client programs (such as Free Agent - >the one I'm using) could add kill file facilties to blank out articles >with rude words in them. >I suppose the only problem is it would kill articles with words such >as "Poshitridge" - a village near where I lived in the Midlands..! >This is off-topic but a thought anyway... >I haven't looked - are other newsgroups where the original article was >posted having this conversation? Nice bit of bandwidth and disk >storage used up if they are... > <<< Nick Lansley G1KZI>>> >For legal reasons, any messages in this article that reveal >I may have taken part in any illegal activity (either directly >or indirectly) are hereby disclaimed. I hereby state that I >have taken no part in any such activity. So why are you letting the "kiddies"' who could probably teach you a few four letter words, check into alt.pirate.radio? Training subversives are we? >----------------------------------------------------- >Home: http://ourworld.compuserve.com/homepages/nicholas_lansley >E-mail: nick@lansley.demon.co.uk or G1KZI@lansley.demon.co.uk From lwbyppp@epix.net Sat Mar 30 14:14:30 1996 From: zliangas@compulink.gr (Zacharias Liangas) Newsgroups: rec.radio.amateur.antenna Subject: 2-loop antenna questions Date: Thu, 28 Mar 1996 21:10:16 GMT Distribution: world Message-ID: <4jeugp$ikq@venus.compulink.gr> Reply-To: zliangas@compulink.gr dear friends of the list this time i am intending to make an 2-loop antenna for two different bands namely 30 and 60 m (SW use only ) , qhich as per my opinion vould be nice to be included in one mast together so that the 30 mb tobe co-centeresd with the other of 60 mb As per theory the 30mb can be 1.1 m per side and 2.2 m for the 60m They will mainly be used fo local noise cancelling and instead of using variable capacitor to use varactor so that I can remotely yune them Thi is my idea at all. What is your opinion . Can both operate well or the one can effect the other? TIA Zakaria Liang! (namanya untuk kawan sahaja!) From lwbyppp@epix.net Sat Mar 30 14:14:31 1996 From: rchappel@eag.unisysgsg.com (Bob Chappelear) Newsgroups: rec.radio.amateur.antenna Subject: Re: 2m 1/4 Wave Glass Mount Advise Date: Mon, 25 Mar 1996 14:46:16 GMT Message-ID: <4j70m5$sli@email.eag.unisysgsg.com> References: <4j4j60$j05@opal.CyberGate.COM> Reply-To: rchappel@eag.unisysgsg.com (Bob Chappelear) > > 2m 1/4 Wave Glass Mount Advise >You wrote > Anyone have any comments on using a 1/4 wave glass mount antenna > for 2 meters? any and all comments or suggestions would be greatly > appreciated. > Thanks, > Dave Yes I'm using one of those RAT SHACK 1/4 wave glass mounted 2m with a Yaesu-2400. I'm having no problems whatsoever getting out to any of the repeates that I tap from my base station. It is a little less sensitive than my Discone that is up about 30 feet but then that should be expected. I was very carefull to adjust for the lowest possible SWR (about 1.2:1) immediately after installation. Porky KI0AS From lwbyppp@epix.net Sat Mar 30 14:14:32 1996 From: Rich Griffiths Newsgroups: rec.radio.amateur.antenna Subject: Re: 2m antenna for travel Date: Sat, 23 Mar 1996 21:27:02 -0500 Message-ID: <3154B2F6.374C@monmouth.com> References: <31547FDC.52DB@monmouth.com> Rich Griffiths wrote: > > Charlie Fortner wrote: > > > > I am going on a trip with the local Boy Scout troop out west this summer > > and I want some opinions on what antenna(s) I should bring for the times > > we are in a building (a hotel of some sort). > > I think the suggestions in favor of a twin lead dipole are very good. > I have used one and thought it's a good traveling antenna. Take a > roll of tape with you. Sigh ... Freud really knew somthing when he talked about slips. I meant to second the suggestions about twin-lead JPOLES, not dipoles. sri W2RG From lwbyppp@epix.net Sat Mar 30 14:14:34 1996 From: Rich Griffiths Newsgroups: rec.radio.amateur.antenna Subject: Re: 2m antenna for travel Date: Sat, 23 Mar 1996 17:49:00 -0500 Message-ID: <31547FDC.52DB@monmouth.com> References: Charlie Fortner wrote: > > I am going on a trip with the local Boy Scout troop out west this summer > and I want some opinions on what antenna(s) I should bring for the times > we are in a building (a hotel of some sort). I think the suggestions in favor of a twin lead dipole are very good. I have used one and thought it's a good traveling antenna. Take a roll of tape with you. I've also used TV rabbit ears with good results. Every TV I've bought came with a set of collapsible rabbit ears. I took the center insulator apart on one (held together by two screws), removed the twin lead, replaced the twin lead with a short length of RG-58, and reassembled the center insulator. Pretune it by extending each leg to about 19 inches and then fine tuning using a VHF SWR bridge or just watching the output meter on your rig. Then mark where the smaller-diameter bits of the telescoping tubes enter the larger-diameter ones (you only need to do this on one tube of each side, if you think about it), and you can readily reset the antenna to the proper length in your hotel room. THis antenna is small and light, so it travels well. I've pulled gimmicks like removing one of the plastic rods that are used to slide the hotel room's curtains back and forth, taping the center insulator of the antenna to it at right angles, and sticking the antenna out the hotel window a couple of feet. This can work great if you're a few floors up. Rich Griffiths, W2RG From lwbyppp@epix.net Sat Mar 30 14:14:35 1996 From: Tim Rourke Newsgroups: rec.radio.amateur.antenna Subject: Re: 2m antenna for travel Date: Fri, 22 Mar 1996 16:37:58 -0800 Message-ID: References: To: Charlie Fortner On Mon, 18 Mar 1996, Charlie Fortner wrote: > I am going on a trip with the local Boy Scout troop out west this summer > and I want some opinions on what antenna(s) I should bring for the times > we are in a building (a hotel of some sort). I have an Icom IC-T22A > handheld with a Larsen 5/8 wave mag mount (to use on the van when we are > mobile - I really don't want to have to take it off the van for use > inside). I was thinking about making a J-Pole out of copper pipe and > using that, but it would be bigger than I would like it to be. Any ideas, > suggestions, or the like would be greatly appreciated. > BTW - any mods for an IC-2000H would also be appreciated! Thanx! > > -- > Ted Fortner > Wozniac@netdepot.com > KF4GJR > Charlie- You might try making a simple J-pole out of some 300 ohm twin-lead TV antenna wire. This is explained fully in a number of sources, including the book "Your Ham Antenna Companion" published by ARRL ($10). After construction, you can easily roll this one up and stick it in a backpack. Another idea is a 2-element quad made of coat hanger or other stiff wire and a few pieces of wood. It looked like it could be dissassembled for packing. The plans were in a recent issue of QST (within past 6 months). Good luck and 73, Tim Rourke KC7IYH From lwbyppp@epix.net Sat Mar 30 14:14:36 1996 From: chideste@xvnews.unconfigured.domain (Dale Chidester) Newsgroups: rec.radio.amateur.antenna Subject: Re: 2m antenna for travel Date: 25 Mar 1996 19:08:41 GMT Message-ID: <4j6qvp$rib@igate2.pt.cyanamid.com> References: <4iujut$9bv@igate2.pt.cyanamid.com> Reply-To: chideste@xvnews.unconfigured.domain The original article from Clint wasn't too clear on the feed line arrangement at the stub for attaching the coax. It's no problem for those aquainted with J-p oles, but might cause confusion otherwise. Here's my revision of his original drawi ng. In tests, it works much better than the rubber duckie on 2 meters with the fee d point at 1" rather than 1/4", but isn't quite as good on 70 cm. as the rubber duckie . Oh well, can't have everything. 73, Dale === 2m/70cm Dual Band J-Pole made from 300 ohm twin lead === _____ ___ Leave wires open at top (don't s hort) | | | | | | O | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 54-1/4" | | 38-1/2" | | | | | | | | | | | | | | _| | | | N |_ _|__ | | | | | | | | | | | | | | | | | | | 15-3/4" | | | | | ,-> | | <---. | Attach coax 1" up from bottom | | | | 1" | | _|_ | |_______| __ |_|__ Short wires together at bottom | | | | Coax Inner Coax Outer Conductor Conductor SWR is 2:1 across the 2m band and from 435mhz to 450mhz on the 70cm band. 1. Use good quality TV twin lead. Cut to 54 1/2" overall. Strip 1/4" at bottom and short wires together 2. Strip insulation at the solder point for coax feedline 1" from bottom. 3. Cut out and remove the 1/2" long notch N. 4. Feed with a length of 50 ohm coax and terminate with the appropriate connector. Tape coax at feedpoint to the twin lead, or use heat shrink, and make sure the joints are insulated from each other. 5. Antenna may be sleeved inside 1/2" PVC for outside mounting or hung on a loop of string run thru hole O. From lwbyppp@epix.net Sat Mar 30 14:14:37 1996 From: NEWS@PSYC (NEWS) Newsgroups: rec.radio.amateur.antenna Subject: Re: 2m automobile antenna? Date: 25 Mar 1996 05:32:44 GMT Message-ID: <4j5b5s$bks@cantua.canterbury.ac.nz> References: <3154236c.573434159@news.smartlink.net> In article <3154236c.573434159@news.smartlink.net>, What@wonder.net says... > > Just want to hear from anybody on a 2 meter antenna they use >in their autos, that's easy to put on and off the vehicle >Bud hello Bud, just a short message about removeable 2m mount. I have recently seen a rather neat idea in Mobile Ham, March 1996, I can send you a copy if you wish. 73 Winton. w.bell@canterbury.ac.nz From lwbyppp@epix.net Sat Mar 30 14:14:39 1996 From: baack@monet.umecut.maine.edu (Jason Baack) Newsgroups: rec.radio.amateur.antenna Subject: Re: 3 Element VHF Yagi Date: 26 Mar 1996 22:27:28 GMT Message-ID: <4j9r0g$113i@sol.caps.maine.edu> References: <3151B557.22DD@som-uky.campus.mci.net> In article <3151B557.22DD@som-uky.campus.mci.net>, smerrick@som-uky.campus.mci.net says... > >Would anyone happen to have plans for a small 2 meter 3 or 4 element >yagi? I am trying to build an antenna to go indoors in a second story >apt., but still get modest gain. I have seen one made by mfj that is 3 >element and 2.75' long. Has anyone used here used this antenna before? > If so, what's the gain on it, and does perform well? Thank you for the >info. > >73's >Shelby >KE4AKA In the 1995/96 ARRL Construction handbook, there is a great design for a 3 element yagi made out of hobby rod and PVC pipe. My total cost was 4 hours and $12.00. Much cheaper than the $30.00 MJF antenna + shipping. I made mine so it has retractable elements, BACKPACKING here I come.! I put it to the test and measured a 1.3 to 1 at 144.5 and 1.6 to 1 at 148.00 (this was without additional tweaking and tuning..) Dementions were some thing like this: Boom = 2 18" sections connected py a PVC T connector (3/4" PVC) |-- 18" -- | |-- 18" --------| --------------- ++++ ------------------ front element is 35" and 1/4 to 1/2" in from the end of the boom director is 40" and 1\2 to 1\4" in from the back of the boom 16' from the director is the (middle of the two feed elements) _ | : | : | |---- 16"-------------| : | End element 40" 38-37" : | : | : _ Each lenght will be some where around 19.xx there is a 1/4 " seperation between the two, and the stick out of the boom approx 1/4" on theoppisite side of the reflector. Braid to one side, center conductor to the other. The support was 3/4" PVC at 42 inches (so I could store the elements in side it) Simple and esay to use. Email me if you can't undstand my cryptic directions.. Jason N1RWY baack@maine.maine.edu From lwbyppp@epix.net Sat Mar 30 14:14:42 1996 From: rikoski@niia.net (Rick Rikoski) Newsgroups: rec.radio.amateur.antenna Subject: Re: 300 vs 450 ohm ladder line Date: Fri, 22 Mar 1996 16:21:51 -0500 Message-ID: References: <4is2db$8oj@chnews.ch.intel.com> <4isdh6$g1k@crash.microserve.net> In article <4isdh6$g1k@crash.microserve.net>, jackl@pinetree.microserve.com (WB3U) wrote: > tom_boza@ccm.ch.intel.com (WB7ASR) wrote: > > >What are the major differences and advantages/disadvantages of using > >either? What about wire gage? Catalogs sell different sizes. The 450 ohm ladder line will have significantly lower loss at vhf and uhf. This will show up as improved signal to noise ratio at your receiver. On transmit, the larger wire gage will give better efficiency, ie more signal transmitted per watt coming from your final, everything else being equal. -- Rick Rikoski Chicago/Indiana Dunes rikoski@niia.net From lwbyppp@epix.net Sat Mar 30 14:14:43 1996 From: cmoore@vegas.ch.intel.com (Cecil A. Moore~) Newsgroups: rec.radio.amateur.antenna Subject: Re: 300 vs 450 ohm ladder line Date: 24 Mar 1996 04:20:25 GMT Distribution: world Message-ID: <4j2ii9$18a0@chnews.ch.intel.com> References: <4is2db$8oj@chnews.ch.intel.com> In article <4is2db$8oj@chnews.ch.intel.com>, WB7ASR wrote: >What are the major differences and advantages/disadvantages of using >either? What about wire gage? Catalogs sell different sizes. > Haven't seen any answers so here's mine. 450 ohm ladder line is lower loss than 300 ohm ladder line. #18 gauge wire will handle more power than #20 gauge wire. 300 ohm ladder line matches low impedances better than 450 ohm ladder line. 450 ohm ladder- line matches high impedances better than 300 ohm ladder line. The range of SWRs on 300 ohm ladder line that will result in a 50 ohm SWR of less than 2:1 at a current node is 3:1 to 12:1. The range of SWRs on 450 ohm ladder line that will result in a 50 ohm SWR of less than 2:1 at a current node is 4.5:1 to 18:1. You can route 300 ohm ladder line closer to metal than you can 450 ohm ladder line. 450 ohm line has a higher velocity factor. If you achieve a Z0-match you can get away with using a 4:1 balun on the 300 ohm ladder line. From a performance standpoint, I doubt you can tell the difference. 73, Cecil, KG7BK, OOTC (not speaking for my employer) From lwbyppp@epix.net Sat Mar 30 14:14:44 1996 From: jgedmond@hic.net (James G. Edmondson) Newsgroups: alt.radio.scanner,alt.radio.pirate,aus.radio,rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc,rec.radio.scanner,rec.radio.shortwave,uk.radio.amateur Subject: Re: ____, my FM-25 is ____ed! What to do?? Date: 24 Mar 1996 01:57:38 GMT Message-ID: <4j2a6j$jrk@news.hic.net> References: <314C74DA.2BB3@shadow.net> <4iruql$66n@mars.spaceworks.com> <4itlar$3pd@tube.news.pipex.net> <31548C17.6F65B43E@sinister.com> In article <31548C17.6F65B43E@sinister.com>, drwho@sinister.com says... > >Wendell Millman wrote: >> > >> Must we keep this stuff going, as this SUBJECT looks realy bad everytime one >> goes to read this news group......lets drop the SUBJECT guys it looks bad. >> > >You people are a bunch of pretentious old farts. So the guy gets a >little frustrated and says he accidently FUCKED UP his transmitter. Big >deal. That's the way alot of people really talk. The Internet is a >common meeting place, that is not censored (at least not yet) and if you >are going to get so bent out of shape over a little bit of profanity, >you are not going to be able to reap the advantages of the net. So get >real, okay? He's not really that bad... > >-----------=?> Doctor Who H&R Company 18 Canal St P O Box 122 Bristol PA 19007-0122 Voice - 1-800-848-8001 FAX - 215-788-9577 Has 1" wide x 18 yards Copper Shielding tape for $14.50 per roll. Doug KC8CGX From lwbyppp@epix.net Sat Mar 30 14:14:46 1996 From: mcewenjv@songs.sce.COM (MCEWEN, JAMES) Newsgroups: rec.radio.amateur.antenna Subject: Antenna info from the Internet Date: 27 Mar 96 17:01:32 GMT Message-ID: <9602278279.AA827946157@ccgate.songs.sce.com> If you only have E-Mail access to the I-Net, there are several ways you can get info mentioned in Ham-Ant. One is to use an Agora server . For example, to get a sample page of the RadioAdventure newsletter( from AntennaWest), send the following E-mail TO: agora@info.lanic.utexas.edu SUBJECT: Body: send http://www.far.net/radioadventure/weekly.htm For more info on how to access the Web through E-mail get "Accessing the Internet By E-Mail", a free publication updated about 4 or 5 times a year. To get the latest edition, send e-mail to one of the addresses below. To: mail-server@rtfm.mit.edu (for US, Canada & South America) Enter only this line in the BODY of the note: send usenet/news.answers/internet-services/access-via-email To: mailbase@mailbase.ac.uk (for Europe, Asia, etc.) Enter only this line in the BODY of the note: send lis-iis e-access-inet.txt You can also get the file by anonymous FTP at one of these sites: Site: rtfm.mit.edu get pub/usenet/news.answers/internet-services/access-via-email Site: mailbase.ac.uk get pub/lists/lis-iis/files/e-access-inet.txt Jim McEwen, KA6TPR My disclaimer: "I only wish I got paid for doing this!" From lwbyppp@epix.net Sat Mar 30 14:14:48 1996 From: mcewenjv@songs.sce.COM (MCEWEN, JAMES) Newsgroups: rec.radio.amateur.antenna Subject: Antenna info from the Internet Date: 29 Mar 96 17:46:22 GMT Message-ID: <9602298281.AA828121665@ccgate.songs.sce.com> If you only have E-Mail access to the I-Net, there are several ways you can get info mentioned in Ham-Ant. One is to use an Agora server . For example, to get a sample page of the RadioAdventure newsletter( from AntennaWest), send the following E-mail TO: agora@info.lanic.utexas.edu SUBJECT: Body: send http://www.far.net/radioadventure/weekly.htm For more info on how to access the Web through E-mail get "Accessing the Internet By E-Mail", a free publication updated about 4 or 5 times a year. To get the latest edition, send e-mail to one of the addresses below. To: mail-server@rtfm.mit.edu (for US, Canada & South America) Enter only this line in the BODY of the note: send usenet/news.answers/internet-services/access-via-email To: mailbase@mailbase.ac.uk (for Europe, Asia, etc.) Enter only this line in the BODY of the note: send lis-iis e-access-inet.txt You can also get the file by anonymous FTP at one of these sites: Site: rtfm.mit.edu get pub/usenet/news.answers/internet-services/access-via-email Site: mailbase.ac.uk get pub/lists/lis-iis/files/e-access-inet.txt Jim McEwen, KA6TPR My disclaimer: "I only wish I got paid for doing this!" From lwbyppp@epix.net Sat Mar 30 14:14:49 1996 From: dpshack@dataplusnet.com Newsgroups: rec.radio.amateur.antenna Subject: Re: Antenna Modeling Software Date: 27 Mar 1996 03:23:21 GMT Message-ID: <4jacb9$6qa@news.inc.net> References: <31506320.2048486@news.borg.com> Scott, check page 184 on the April 1996 QST. There is an ad on the top left c orner for Brian Beezley, K6STI who writes antenna modeling software. On page 164 of the same issue of QST is an ad for W7EL. C heck the ARRL home page for links to an FTP site with some software. Try FTP://VE7TCP .ampr.org/arrl for a mirror of the ARRL site. There are some antenna modeling programs and optimizing programs available there also. Hope this helps! 73 de Dave, KB9KQA From lwbyppp@epix.net Sat Mar 30 14:14:49 1996 From: hamop@aztec.asu.edu (CHARLES J. MICHAELS) Newsgroups: rec.radio.amateur.antenna Subject: Re: Antenna Modeling Software Date: 29 Mar 1996 06:57:34 GMT Message-ID: <4jg1ku$h87@news.asu.edu> Scot Souva asked Anyone know what software is available for antenna modeling and design? The only thing I have ever heard of was the ARRL "Method of Moments" software. But, I can't seem to find any reference to it. Ideas? Scot See Roy Lewallan's ads in QST for ELNEC and EZNEC Charlie, W7XC -- From lwbyppp@epix.net Sat Mar 30 14:14:50 1996 From: John Fleming Newsgroups: rec.radio.amateur.antenna Subject: Antenna Myths Dispelled, Part I Date: Mon, 25 Mar 1996 16:39:51 +0500 Message-ID: <31568607.75FA@mailbox.mcs.net> Check out the weekly news article from RadioAdventure, Antenna Myths Dispelled, Part I: Antenna Patterns, Radiation Angle, and Gain http://www.far.net/radioadventure/weekly.htm John N9NDH From lwbyppp@epix.net Sat Mar 30 14:14:51 1996 Newsgroups: rec.radio.amateur.antenna From: junger@mtn.er.usgs.gov (John Unger) Subject: Re: Antenna Myths Dispelled, Part I Message-ID: <1996Mar26.134514.28262@rsg1.er.usgs.gov> References: <31568607.75FA@mailbox.mcs.net> Date: Tue, 26 Mar 1996 13:45:14 GMT John Fleming wrote: >Check out the weekly news article from RadioAdventure, > >Antenna Myths Dispelled, Part I: >Antenna Patterns, Radiation Angle, and Gain > >http://www.far.net/radioadventure/weekly.htm > >John N9NDH Interesting, but where are the figures? 73 - John, W3GOI -- John Unger From lwbyppp@epix.net Sat Mar 30 14:14:52 1996 From: donstone@gate.net (Don Stoner) Newsgroups: rec.radio.amateur.antenna Subject: Antenna Restrictive Covenants Home Page Date: 29 Mar 1996 14:03:43 GMT Message-ID: <4jgqjv$mg6@news.gate.net> Finally, the Antenna Restrictive Covenants Homepage is up and running on my system. The new address is: http://www.gate.net/~donstone/antenna.html I would appreciate any suggestions on how this resource can be made more usefu l and any contributions (particularly on hidden antennas) are welcome. 73 Don Stoner, W6TNS From lwbyppp@epix.net Sat Mar 30 14:14:53 1996 From: Lanier.r.a@nort.bwi.wec.com (Robert A. Lanier) Newsgroups: rec.radio.amateur.antenna Subject: antennae for spread-spectrum Date: Thu, 21 Mar 1996 23:27:02 GMT Message-ID: <4isodo$8s7@cc2000.kyoto-su.ac.jp> I am looking for information on antennae to use for spread-spectrum communications. Can you use a regular Yagi or dipole? Does it have to have special characteristics, other than a wide bandwidth? Also, I would like to hear from those who QSO to europe on a regular basis. What pitfalls can a rookie avoid, what can he/she do to have a successful QSO? Any help would be much appreciated. 73s de Tony, KE4ATO From lwbyppp@epix.net Sat Mar 30 14:14:54 1996 From: Michael_H._Heiler@news.pol.org (Michael H. Heiler) Newsgroups: rec.radio.amateur.antenna Subject: are the bands dead Date: Sat, 23 Mar 96 10:28:16 -0600 Message-ID: <7089481.ensmtp@news.pol.org> I live in an apartment and have not been on HF for about 2 years because of no place to put an antenna I have just now put one up. I put up a loop 30' x 60' I can tune most bands flat. but I don't here any thing. I was wondering if the bands are dead or if it is my antenna. Because of restrictions I had to hide my antenna so I used avery small wire(from the wiendings of a deflection yoke from a tv). My loop gose around the apt. bldg. by the way no one can see it. unless they were trying to find it. I stappeld it about 10' up and under the botum side of the lapp sidding. this was done at night so I would not be seen and asked what I was doing. i am telling this incase any one may wont to try it. I did try using 2- 80mtr. ham sticks in an inverted V but mu reception then was bad and I just thought that it was the atenna. I then tried using only one ham stick 1/4 wave , and tying the other end to the hot-warter heatig system. this seemed to get me out a littlle better but not good. sme thing. poor reception. any way any help would be great. mike KA0ZLG / AFA3JQ From lwbyppp@epix.net Sat Mar 30 14:14:55 1996 From: dave@diusys.cms.udel.edu (Dave Dabell) Newsgroups: rec.radio.amateur.antenna Subject: Re: ATV antenna Date: 27 Mar 1996 15:08:52 GMT Message-ID: <4jblm4$fkk@news.udel.edu> References: <4jaib2$r2k@parlor.hiwaay.net> Both the arrl handbook and antenna book have plans for 432 yagis designed by K1FO. Included in the article is information on building them in a variety of sizes and scaling them to atv freqs. 73, dave wa3u ke4eer@hiwaay.net wrote: : I want to build an ATV Yagi but am having a hard time finding any : documentation even in the ARRL Antenna hadbook. I want to build : something on the order of a 13 <-> 16el yagi, Any help would be : appreciated. This is my first message to any newsgroup so i hope it : makes it alright. From lwbyppp@epix.net Sat Mar 30 14:14:56 1996 Newsgroups: rec.radio.amateur.antenna From: n4lq@iglou.com (Steve Ellington) Subject: Re: balanced tuner techniques Message-ID: References: <4j27k7$15mm@chnews.ch.intel.com> Date: Sun, 24 Mar 1996 13:06:08 GMT I did the same thing a few years ago. It works but it is a bit messy. I've been looking for bungie feeders ever since. Yes, bungie wire would allow us to just pull on the feeder and change the tuning. No more messy relays. Just two pieces of strech wire and a couple of cloths-pins is all you need. -- Steve Ellington N4LQ@IGLOU.COM Louisville, Ky From lwbyppp@epix.net Sat Mar 30 14:14:57 1996 From: Cecil Moore Newsgroups: rec.radio.amateur.antenna Subject: Re: balanced tuner techniques Date: Sun, 24 Mar 96 10:19:18 -0500 Message-ID: References: <4j27k7$15mm@chnews.ch.intel.com> Steve Ellington writes: >I did the same thing a few years ago. It works but it is a bit messy. Hi Steve, since when did hams worry about being messy? :-) Why didn't you publish information on your design? It would have saved me a lot of time. Seriously, the mess can be located outside and the tuning is a lot easier than my balanced tuner and equal or better in efficiency. It is ideal for automation. And mine's not all that messy. On my particular antenna, the longest loop is only 8 ft. long (2.5 feet diameter). 73, Cecil, KG7BK, OOTC From lwbyppp@epix.net Sat Mar 30 14:14:58 1996 From: w8jitom@aol.com (W8JI Tom) Newsgroups: rec.radio.amateur.antenna Subject: Re: baluns in G5RV???. Date: 26 Mar 1996 16:34:29 -0500 Message-ID: <4j9nt5$iep@newsbf02.news.aol.com> References: <360fkdg60.alamito@banana.speed.satlink.net> In article <360fkdg60.alamito@banana.speed.satlink.net>, anibal@banana.speed.satlink.net (Anibal Aguirre) writes: >Electromagnetics theory affirm that if exist an impedance change surface in >this surface appears a reflected wave.The solution at this are the baluns. >In "the reality".What`s true??. >Any answers will be appreciate. >thanks. >Anibal Aguirre What is true is the G5RV or any dipole type antenna should have a balun where the transition of balanced to unbalance conditions are made. A choke-type balun, made either with a sleeve of beads, a twisted pair or coax coil over a core, or a twisted pair or coaxial line over an air core all work very well. I use the coax over an air core myself. Not using a choke balun is foolish, since they are so easy to build. 73 Tom From lwbyppp@epix.net Sat Mar 30 14:14:59 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: baluns in G5RV???. Date: Wed, 27 Mar 96 19:00:32 GMT Message-ID: <4jc3kf$ksg@crash.microserve.net> References: <360fkdg60.alamito@banana.speed.satlink.net> anibal@banana.speed.satlink.net (Anibal Aguirre) wrote: >HI FRIENDS: in the discution about the message "ingnorant >question....G5RV" many friends says that: "..G5RV works well without >balun for match 50 to 300omhs lines.." Electromagnetics theory affirm >that if exist an impedance change surface in this surface appears a >reflected wave.The solution at this are the baluns. >In "the reality".What`s true??. The purpose of the balun in most systems (including the G5RV) is not impedance transformation. The impedance seen at the feedpoint of the ladder line varies greatly from band to band and no single transformation ratio will match it. Rather, the purpose of the balun is to make the transition from unbalanced transmission line (coax) to balanced feed (ladder line or twinlead). This keeps RF current within the coax from flowing back to the rig on the outside of the shield. Unfortunately, the variation is feedpoint impedance presented by the G5RV can deteriorate the performance of the balun, as discussed in the other thread. 73, Jack WB3U From lwbyppp@epix.net Sat Mar 30 14:15:00 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: Beam Antenna for 27Mhz Date: Fri, 22 Mar 96 19:34:13 GMT Message-ID: <4iuvm5$rmo@crash.microserve.net> References: <4itcnb$i7m@newsbf02.news.aol.com> zandor1@aol.com (ZANDOR1) wrote: >I would like to try something different and would appreciate any help >that can be given. I do not want to get a linear for my car. That's good. It's illegal. >I would like to know if it is possible to build or buy a beam antenna >for CB radio? If so how is it done? There are no designs available for such an antenna. It was discovered many years ago that 27 MHz is useless for communications. From lwbyppp@epix.net Sat Mar 30 14:15:01 1996 From: mcewenjv@songs.sce.COM (MCEWEN, JAMES) Newsgroups: rec.radio.amateur.antenna Subject: Collapsable Whips Date: 29 Mar 96 17:19:59 GMT Message-ID: <9602298281.AA828120117@ccgate.songs.sce.com> Dave WB0GAZ dgf@netcom.com asked: >I am interested in finding some really long COLLAPSIBLE whips, Small Parts, Inc. 13980 N.W. 58th Court PO.Box 4650 Miami Lakes, FL 33014-0650 1-800-220-4242 Call them for a catalog. They have telescoping tubing in brass,copper and aluminum, and 304 Stainless and Stainless wire in various sizes an lengths. Also of interest to the antenna experimenter are stainless steel nuts & bolts, metric & inch sizes; Teflon & phenolic rods & sheets,nylon screws & nuts, and lots of other "good junk". Jim McEwen, KA6TPR standard disclaimer: "I only WISH I was getting paid for doing this." From lwbyppp@epix.net Sat Mar 30 14:15:01 1996 From: Steve Lewis Newsgroups: rec.radio.amateur.antenna Subject: Corner Beam Date: Tue, 26 Mar 1996 01:51:24 -0800 Message-ID: <3157BE1C.7952@netusa1.net> 73 magazine just did a review of the Arrow Corner Beam manufactured by Antennas West. It boasts 10db gain, 40db FTB ratio, and an SWR of 1.2:1 over the entire band. If anyone out there has any experience with this antenna, let me know what you think of it. Thank You in Advance -- Steve Lewis (n9jhg@netusa1.net) Just my opinion! :-) 73 cul From lwbyppp@epix.net Sat Mar 30 14:15:03 1996 From: tim@address.net (t²s) Newsgroups: rec.radio.amateur.antenna Subject: Re: Corner Beam Date: Mon, 25 Mar 1996 15:17:44 GMT Message-ID: <4ja1bd$lr1@tofu.alt.net> References: <3157BE1C.7952@netusa1.net> Steve Lewis wrote: >>73 magazine just did a review of the Arrow Corner Beam manufactured by >>Antennas West. It boasts 10db gain, 40db FTB ratio, and an SWR of 1.2:1 >>over the entire band. If anyone out there has any experience with this >>antenna, let me know what you think of it. Thank You in Advance >> >>-- >>Steve Lewis (n9jhg@netusa1.net) >>Just my opinion! :-) 73 cul Actually I have had good success with the dual band version of this antenna. Assembly was a bit painful due to the number of elements and the instructions left a lot to be desired. The fasteners used to secure the elements to the boom were also not the best choice. I found that using stainless steel socket head cap screws instead to the round head machine screws made the assembly easier. t²s tim@address.net **********NOTICE********** Unsolicited *commercial* email is subject to download/archival fee of $525.00 US per message. Viewing this message and/or E-mailing to the forementioned address denotes acceptance of these terms. From lwbyppp@epix.net Sat Mar 30 14:15:03 1996 From: parf@aol.com (Parf) Newsgroups: rec.radio.amateur.antenna Subject: Re: cross polarization losses at 2m Date: 28 Mar 1996 00:03:24 -0500 Message-ID: <4jd6is$sda@newsbf02.news.aol.com> References: <4j7j3o$t3m@mars.hyperk.com> Reply-To: parf@aol.com (Parf) Typically cross polarization losses are stated to be 20 dB- a huge loss if there is no scattering of the polarization. You will be better off to preserve the polarity of the station you are trying to work. End fed half waves (like a J pole) are easy to build and mount vertically. 73, Dale WA2YPY From lwbyppp@epix.net Sat Mar 30 14:15:04 1996 From: jpardelan@aol.com (JPARDELAN) Newsgroups: rec.radio.amateur.antenna Subject: Re: Cushcraft R-5 on wrong bands Date: 25 Mar 1996 14:03:11 -0500 Message-ID: <4j6qlf$imt@newsbf02.news.aol.com> References: <92829.jackson@mail.us.net> Reply-To: jpardelan@aol.com (JPARDELAN) Jay, The R-5 has a balun transformer and an impedence matching transformer in the black match box at the bottom. If you use this antenna on bands it was not designed for, I guarantee that you will burn up the impedence matching transformer in the black box. These transformers are ferrite toroids and will heat up, melt the plastic box, burn the circuit board black, and crack the ferrite material. You can "match" with a tuner but on "not designed for" bands much of your power will be given up as heat in the toroids (especially the impedence matching transformer). Cushcraft wants over $100.00 to replace the matchbox. My advice is to use this antenna ONLY on the bands it was intended for (believe me, I know others who found this out the hard and expensive way). 73, John (KF9SF) From lwbyppp@epix.net Sat Mar 30 14:15:06 1996 From: "Carmine M. Iannace" Newsgroups: rec.radio.amateur.antenna Subject: Delta Loop Question Date: Tue, 26 Mar 1996 14:34:27 -0500 Message-ID: <315846C3.5E12@bu.edu> I've been reading William Orr's "Antenna Handbook" and have found some interes ting plans for a G3AQC delta loop. The antenna is basically a vertical full wave loop on 80m (about 280 feet of wire)shaped like an equalateral triangle with a horizontal side at the top and two sides sloping inward to form the feedpoint at the bottom like the letter V. This type of bottom apex feed produces vertical polarization. This antenna is supposed to be the best type of antenna for the lower HF bands according to the book, since it exhibits both low angle (30 degrees) and high angle radi ation which a horizontal dipole cannot do if mounted at a 1/2 wavelength or less abo ve the ground. I am considering building this antenna as a main HF multiband antenna. I would like to hear from anyone who has tried it. I am also concerned about blasting my neigh bors with RFI since this antenna's feedpoint is near ground level as opposed to a dipole that would have a feedpoint at 40 or so feet above the ground and thus would probab ly cause less RFI. As you can guess a 80m dipole fed with open wire feedline is my alte rnative. Any comments regarding this matter are appreciated. Carmine Iannace KA2PAP The Mountain Top Homepage http://members.aol.com/greeneny From lwbyppp@epix.net Sat Mar 30 14:15:08 1996 From: Charlie Panek Newsgroups: rec.radio.amateur.antenna Subject: Re: Delta Loop Question Date: Wed, 27 Mar 1996 11:13:32 -0800 Message-ID: <3159935C.51ED@lsid.hp.com> References: <315846C3.5E12@bu.edu> Carmine M. Iannace wrote: > > I've been reading William Orr's "Antenna Handbook" and have found some inter esting plans > for a G3AQC delta loop. The antenna is basically a vertical full wave loop on 80m > (about 280 feet of wire)shaped like an equalateral triangle with a horizonta l side at > the top and two sides sloping inward to form the feedpoint at the bottom lik e the letter > V. This type of bottom apex feed produces vertical polarization. I don't believe this is correct. Feeding a full wave loop at the bottom (or top) center, (no matter what the shape), will result in horizontal polarization, not vertic al. Feed it at the side for vertical polarization. though I'm not sure where the "side " would be on a delta loop. > > This antenna is supposed to be the best type of antenna for the lower HF ban ds according > to the book, since it exhibits both low angle (30 degrees) and high angle ra diation > which a horizontal dipole cannot do if mounted at a 1/2 wavelength or less a bove the > ground. "Best antenna" is a pretty ambiguous statement. Kinda depends on what you want. If your mostly interested in DX, a vertical with a good ground system may be y our "best" transmitting antenna. Maybe "best comprimise" is what you're trying to say. > > I am considering building this antenna as a main HF multiband antenna. I wou ld like to > hear from anyone who has tried it. I am also concerned about blasting my nei ghbors with > RFI since this antenna's feedpoint is near ground level as opposed to a dipo le that > would have a feedpoint at 40 or so feet above the ground and thus would prob ably cause > less RFI. As you can guess a 80m dipole fed with open wire feedline is my al ternative. > Any comments regarding this matter are appreciated. I'm a little confused here. How high off the ground are you mounting the de lta loop? If it's only 40 feet, the feet point will be lying on the ground! (if you try to maintain that equilateral triangle shape). The height of an an equilateral triangle wi th lamda/3 sides, is about lambda*.29, or around 78 feet on 80 meters. If you're limited to a height of 40 feet, I'd stick with the dipole. All that being said, I shouldn't give the impression that I'm against delta loops. I've had a 20m loop up as my main high band antenna for about 10 years now. I've worked DXCC with it, and it's been a great antenna. (It was actually inspired by W6SAI, but that's another story; as seems to be typical with Orr, his design ( from the old Ham Radio mag) didn't *quite* work the way he said it would, but after a little tweaking, I had a great 3 band antenna). Our club also uses a delta loop beam to great effect on 40 meters for Field Day. The triangle is upside down in this case, with the apex at the top (about 90 f eet between two tall cedar trees), and the feedpoint about 40 or 50 feet up in the middle of the horizontal section. Not the optimal orientation, but easily supported with on e rope. One nice feature about loop antennas in general is that they are somewhat lo wer in noise, especially if polarized horizontally. > > Carmine Iannace KA2PAP > The Mountain Top Homepage > http://members.aol.com/greeneny -- Charlie Panek KX7L Hewlett Packard Company charlier@lsid.hp.com Lake Stevens Division Everett, Washington From lwbyppp@epix.net Sat Mar 30 14:15:09 1996 From: W2FOE@gnn.com (Merv Stump) Newsgroups: rec.radio.amateur.antenna Subject: Re: Delta Loop Question Date: Thu, 28 Mar 1996 20:09:17 Message-ID: <4jfd9b$sp3@news-e2c.gnn.com> References: <4je8r3$frl@linus.mitre.org> I've used full-wave loops on 80 meters in a variety of configurations and orientations including the one you describe (although my dimensions were approximately 40 feet on the vertical sides and 95 feet on the horizontal sides). It did perform well from the east coast into Europe, but I found that the longer I could get the vertical sides (up to a quarter wavelength) the better it performed. However, the configuration which performed best at low angles was a delta with the apex at the bottom, and fed in one of the top corners. Regards, Merv From lwbyppp@epix.net Sat Mar 30 14:15:11 1996 From: jacosta@hiline.net Newsgroups: rec.radio.amateur.antenna Subject: diplexer design Date: Mon, 25 Mar 1996 21:17:10 GMT Message-ID: <4j75nl$6qi@mercury.hiline.net> the project I am working on requires a diplexer to be designed: Transmitter: ____ /| | |/ | | | <--horn antenna |____ |\ | || \| || || || || <-- coax || (tower) || ___ ||____ | | | | <-- Diplexer |________| || || || || __||__ _ ||___ | | | | <--transmitters |____| |____ | XMTR#1 XMTR #2 In this system, the outputs of two transmitters operationg at different frequencies are combined using a device known as a "diplexer", are sent up a long cable to the top of the tower, and are transmitted using a horn. The diplexer, to operate, must take energy from transmitter #1 and deliver it to the antenna, without letting any enrgy get to transmitter #2, and vice versa. What I was wondering is how a diplexer design can be acheived. That is after BP filtering the desired frequencies from each transmitter with parallel stubs, can I just connect the two XMTR output lines and expect them to mix? Thanks for responding. > xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx From lwbyppp@epix.net Sat Mar 30 14:15:12 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: Dust in yer reflector Date: Mon, 25 Mar 96 22:37:21 GMT Message-ID: <4j77ig$1pl@crash.microserve.net> References: rikoski@niia.net (Rick Rikoski) wrote: >Suppose I want to make a UHF or microwave parabolic-reflector >antenna. >Suppose I don't want to make the reflector out of metal. >Suppose I have the means to cast epoxy into a precisely parabolic >form. > >Could I simply mix aluminum dust or graphite into the liquid epoxy >and then cast the mixture into parabolic shape and expect the >resulting dish to reflect signal? > >How well might this work? What are the limitations? Has anyone >actually built antennas this way? I don't have a precise answer to your questions, but it sounds as though the process could be difficult to control. For instance, what if the particles settle before the epoxy cures? If I had a parabolic mold, I would line it with aluminum or stainless screening, then layer the metal screen with fiberglass cloth saturated with epoxy. Alternately, you could take the mold and screen to a fiberglass fabricating shop and let them blow on a nice thick coating of 'glass with their chopper gun. :) 73, Jack WB3U From lwbyppp@epix.net Sat Mar 30 14:15:13 1996 From: lmckelp@aol.com (LMcKelp) Newsgroups: rec.radio.amateur.antenna Subject: Failed HF Mobile Attempt Date: 29 Mar 1996 08:30:08 -0500 Message-ID: <4jgol0$3gp@newsbf02.news.aol.com> Reply-To: lmckelp@aol.com (LMcKelp) Earlier this week I attempted to work HF mobile using a borrowed company car on a company trip. My setup was as follows: Icom 735 MFJ 941E tuner Valor 40M mobile whip "CB" style trunk mount My problem was that the SWR would not remain constant with the application of power. With much difficulty, I could get the SWR down to acceptable with the radio in low power mode, but when I raised the output power, the SWR jumped to infinity each time. This occurred on 40, but when I replaced the whip with a continuously loaded 4 ft long CB antenna, the setup worked fine on 10, 11 (on a CB radio that I brought along also), 12, and 15 and 17 meters. As it was a company car that I was to return at the end of the trip, I didn't attempt any special grounding of the trunk mount, using only the 2 Allen set screws cutting through the paint on the underside of the trunk for connection. Any idea why this would not work on 40, but worked fine on the higher bands? By the way, I peaked the 40 meter setup on receive to get close and save my finals first, and after adding power and losing the match, the receive signal was lower also. Help! The company cars are my only chance at HF mobile, as my Nissan Maxima has a big console that allows no place to put the radio permanently. Thanks in advance, Levi N5ZFM From lwbyppp@epix.net Sat Mar 30 14:15:14 1996 From: kk5ep@aol.com (KK5EP) Newsgroups: rec.radio.amateur.antenna Subject: Force 12 rotatable dipoles Date: 27 Mar 1996 16:31:11 -0500 Message-ID: <4jcc2v$hho@newsbf02.news.aol.com> Reply-To: kk5ep@aol.com (KK5EP) I'm considering buying one of the Force 12 rotatable dipoles for 80 meters to mount above a C4XL. Has anyone had any experience with this particular antenna? 73, Mike KK5EP. From lwbyppp@epix.net Sat Mar 30 14:15:15 1996 From: at738@FreeNet.Carleton.CA (David Toste) Newsgroups: rec.radio.amateur.antenna Subject: Re: free TH6-DXX beam in Toronto Date: 26 Mar 1996 05:28:40 GMT Message-ID: <4j7va8$e7j@freenet-news.carleton.ca> References: <4j5vv2$dqo@sunburst.ccs.yorku.ca> Reply-To: at738@FreeNet.Carleton.CA (David Toste) David Stock (ya156039@alumnet.yorku.ca) writes: > I have a TH6-DXX tri-band beam that was carefully taken down on > Saturday March 23. It is in good shape except for the rusty hardware. > It is now behind my garage in Toronto. It is available free to anyone > who can disassemble it for moving and take it away. > David Stock e-mail ya156039@alumnet.yorku.ca > Sorry for the second message. Can you reply back to me at : saturn@interlog.com Since this address(I know it's ottawa but I use it for usenet mail) is alittel flakey. Or if your awake and want to call me after 12am-6am (at work) 416-203-5945 Thanks -- David Toste [VE3TOS] Internet - aa521@freenet.toronto.on.ca Don Mills, Ontario. SWLOGit - The Ultimate Shortwave Listeners ftp.virginia.edu /pub/swlogit/ Software. (Fidonet: 1:250/930) *NEW* http://www.interlog.com/~saturn/SWLOGit.html (SWLOGit Web Page) From lwbyppp@epix.net Sat Mar 30 14:15:17 1996 From: "Carmine M. Iannace" Newsgroups: rec.radio.amateur.antenna Subject: Full Wave Loop Question Date: Tue, 26 Mar 1996 14:33:47 -0500 Message-ID: <3158469B.66C3@bu.edu> I've been reading William Orr's "Antenna Handbook" and have found some interes ting plans for a G3AQC delta loop. The antenna is basically a vertical full wave loop on 80m (about 280 feet of wire)shaped like an equalateral triangle with a horizontal side at the top and two sides sloping inward to form the feedpoint at the bottom like the letter V. This type of bottom apex feed produces vertical polarization. This antenna is supposed to be the best type of antenna for the lower HF bands according to the book, since it exhibits both low angle (30 degrees) and high angle radi ation which a horizontal dipole cannot do if mounted at a 1/2 wavelength or less abo ve the ground. I am considering building this antenna as a main HF multiband antenna. I would like to hear from anyone who has tried it. I am also concerned about blasting my neigh bors with RFI since this antenna's feedpoint is near ground level as opposed to a dipole that would have a feedpoint at 40 or so feet above the ground and thus would probab ly cause less RFI. As you can guess a 80m dipole fed with open wire feedline is my alte rnative. Any comments regarding this matter are appreciated. Carmine Iannace KA2PAP The Mountain Top Homepage http://members.aol.com/greeneny From lwbyppp@epix.net Sat Mar 30 14:15:18 1996 From: davidc@scoot.NETis.COM (David, Michaela & Benjamin) Newsgroups: rec.radio.amateur.antenna Subject: GAP Titan vs Hygain DX-77 Vertical Date: 25 Mar 96 02:15:28 GMT Message-ID: <01BB19C7.165B7760@dns.netis.com.198.186.186.2> I don't know what happened to my recent posting, but here it is again. = Sure hope it stays on long enough to get some feedback! I am cutting back to a minimal setup for a couple of years & need the = best vertical (for a reasonable price) that does not require ground = radials. I think I'm down to the GAP Titan and the Hygain DX-77. I am hoping for complete coverage (or close) for 10-40 incl. WARC. I'm hoping to learn about installation & tuning, durability & operation = during bad weather, and actual band coverage (vs marketing hype) for = these two antennas. All feedback is welcome & responses sent here at Ham-Ant@UCSD.Edu are = requested so all may learn along with me. Thanks & 73, David AA1FA From lwbyppp@epix.net Sat Mar 30 14:15:18 1996 From: sw1gak@polaris.mindport.NET (Spencer Trombly) Newsgroups: rec.radio.amateur.antenna Subject: Re: Ham-Ant Digest V96 #147 Date: 21 Mar 96 04:21:08 GMT Message-ID: References: <199603201230.EAA25159@mail.ucsd.edu> I put some RG 8 X inside a 100 foot length of open braid polyprop line today for strain relief and anti-chafe. Works very well, very strong, and reduces kinking when handling the wire From lwbyppp@epix.net Sat Mar 30 14:15:19 1996 From: Pedro.Braz@gameover.alce.pt (Pedro Braz) Date: Tue, 26 Mar 96 13:54:23 GMT Message-ID: <3157f732@gameover.alce.pt> Newsgroups: rec.radio.amateur.antenna Subject: HF Antenna Hello All. Hi dudes. I Need plans for a HF multiband antenna preferably something of a dipole style that uses 3,7/7/14/18/25/28 MHz Please e-mail to: pedro.braz@gameover.alce.pt If you are going to send .gif files please use uucode thks in advance Pedro From lwbyppp@epix.net Sat Mar 30 14:15:22 1996 Newsgroups: rec.radio.amateur.antenna From: mack@ncifcrf.gov (Joe Mack) Subject: Re: How do I make a 2m 5/8 antenna? Message-ID: References: <4ii727$3at@hp5.online.apple.com> Date: Mon, 25 Mar 1996 20:34:15 GMT In article <4ii727$3at@hp5.online.apple.com> jospav@eworld.com (Jospav) writes : >I am wondering if anyone here can tell me how to make a 5/8 wave antenna >for use in the 2m band? Can I just get a piece of wire and cut it a >certain length, or is there more to it than that? Is wire something good >to use to make and antenna, or should I use some tubing, or a solid metal >rod? Can anyone here help, by giving a SIMPLE way to make an antenna for >2m use? They appear to be about the same size in the mag mount version as >a CB antenna, can I just cut it the same lenth and use the CB antenna I >already have? > >Thanks for any help > >Josh A 5/8 is non resonant, you need a coil at the base of the antenna to resonate it. So you need a mag mount (or similar), 5/8x2m (approx is OK) of self supporting wire and a coil to resonate the antenna. Start with about 11 turnsover about 3 inches long and 1/2" diam. Use a SWR meter to get the lowest SWR (you may be way off here and will need to do a bit of cut and try). Joe NA3T mack@ncifcrf.gov From lwbyppp@epix.net Sat Mar 30 14:15:23 1996 From: raiar@inlink.com (Gary V. Deutschmann, Sr.) Newsgroups: rec.radio.amateur.antenna Subject: Re: How? 6 Meter J-Pole? Date: Thu, 21 Mar 1996 18:38:56 GMT Message-ID: <4is7bn$if3@news1.inlink.com> References: <315145C1.62B7@azstarnet.com> Buster wrote: >Been thinking about doing a 6-meter J-Pole >I tried modifying the 2-Meter twin-lead design, but I think >my feed points were too low on the antenna. >I'd like to make one out of antenna whip. >It's gonna be big. Preliminary estimates put the 3/4~ side >at 150.5" and the 1/4~ matching stub at 50". >Anyone have experience/measurements for different construction >techniques. I've heard of some with 3/4" copper pipe. I'm >A Little more interested in a finer whip, like Stainless Steel? >Buster, KC7KMJ >Tucson Arizona DM42 >6 & 2 SSB Hi Buster Take a look at my web page http://www.inlink.com/~raiar I have the numbers already worked out. If you want to use stainless wire, it's simple to recalc and leave out the K-Factor in your measurements. TTUL - 73+ de Gary - KG0ZP From lwbyppp@epix.net Sat Mar 30 14:15:24 1996 From: graham@southlin.demon.co.uk (Graham Seale) Newsgroups: rec.radio.amateur.antenna Subject: Re: Ignorant question: What's a G5RV??? Date: Fri, 22 Mar 1996 09:42:20 GMT Distribution: world Message-ID: <19960322.094220.22@southlin.demon.co.uk> References: <314DC5B9.588F@vertex.ucls.uchicago.edu> Reply-To: graham@southlin.demon.co.uk G5RV - Isaac Cohn's question. Hi folks I know I replied first to Isaac, and I deliberately made it anodyne. The G5RV must be one of the most analysed antennas ever, and surely is one of the first ever tried by the new Ham with the smell of fuser oil still fresh on his ticket. To find an antenna that can be put up for less than $15 plus some fun time, that will allow at least an initial exploration of most of the HF Ham Bands has an obvious attraction. The nitty gritty is different! I have always thought it probable that the G5RV was built first and analysed later to aquire the implied kudos of "designed" . The whole thing looks like a field day lash-up, especially the feeder. When I first saw it, I thought to myself.. "This is a serendipity antenna! They were short of feeder, so they hung together the pieces they had to hand. Subsequently, to their delight, they discover that a reasonable match can be coaxed out on several bands" Ahh, such uncharitable thoughts get rapidly tempered when one considers the norms that were prevalent at a time when the "matcher" was usually part of the output stage, "aerial current" was everything, QSY was not so easy, etc. So, deferring to more experienced opinion, I put one up. I have since come across G5RVs often, and have always been disappointed. Usually I can hear stations I cannot work. On 80m it behaves like any low dipole. The signal goes straight up and comes down all over Europe (from UK @ 12metres high). Good for local chat at night if you can stand QRM. Any DX is a real struggle unless you work somebody off the vertically polarised feeder radiation. The variety that uses 75 ohm coax seems prone to feature in TV/RFI problems. Now that I know all the most useful highest current nodes are usually somewhere inside the balanced feeder part, doing a fine job of cancelling each other, I won't use it again. The tradeoff for low cost, quick setup, all bands was just too severe! You can get multiband dipoles by simply driving them from a common feedpoint, or other ways, with less downside. Perhaps my experiences were untypical, and there are thousands of you out there who never had these kind of struggles. I recognise the contribution the G5RV has made to Amateur Radio, but I do not want to contribute to an unjustified mystique. 73s G4WNT -- Graham Seale From lwbyppp@epix.net Sat Mar 30 14:15:25 1996 From: Cecil Moore Newsgroups: rec.radio.amateur.antenna Subject: Re: Ignorant question: What's a G5RV??? Date: Thu, 21 Mar 96 22:51:38 -0500 Message-ID: <51OpV+K.cecilmoore@delphi.com> References: <314DC5B9.588F@vertex.ucls.uchicago.edu> <4imi61$4dp@fcnews.fc.hp.com> <4ip9fo$1lo@fcnews.fc.hp.com> <4irq3l$hqs@fcnews.fc.hp.com> Edward Lawrence writes: > I do have one of my own. What is an OOTC? Only been licenced for >32 years, but I don't know this one. Ya'll young sprouts only been licensed 32 years will just have to wait 8 more years. The Old, Old Timers Club, 3191 Darvany Dr., Dallas, TX 75220-1611 requires 40 years or more. We think the QCWA guys are still wet behind the ears. :-) 73, Cecil, KG7BK, OOTC From lwbyppp@epix.net Sat Mar 30 14:15:27 1996 Newsgroups: rec.radio.amateur.antenna From: dts@peanut.senie.com (Daniel Senie) Subject: Re: Ignorant question: What's a G5RV??? Message-ID: <4j4uqq$fnh@peanut.senie.com> References: <314DC5B9.588F@vertex.ucls.uchicago.edu> <4ioh6b$25j@crash.microserve.net> <4ips4p$k1c@itnews.sc.intel.com> Date: Mon, 25 Mar 1996 02:02:02 GMT In article <4ips4p$k1c@itnews.sc.intel.com>, Cecil Moore wrote: >jackl@pinetree.microserve.com (WB3U) wrote: >> Cecil Moore wrote: >> >>>on 17m, the G5RV has 4 lobes each with 10dbi gain over ground >> >>Is that before or after subtracting the loss in the balun? ;) > >Hi Jack, the original G5RV didn't have a balun :-) Remember >W6SAI reported an SWR of 1.84:1 on 17M using a G5RV with >no balun. > >I was quoting gains from memory. I reran them with EZNEC and it >gave the dipole a two-lobed 5dbi gain over ground and the G5RV >a four-lobed 8dbi gain over ground on 17M. Why would someone >choose 5dbi in two directions when they could have 8dbi in four >directions? I guess I'd rather have the gain in the direction I'd want the signal to go. Those 4 lobes on the G5RV will go at different angles than the lobes produced on 80 meters, or 20 meters, or whatever. Having separate antennas can produce separate results, even if less gain, since the gain can then be oriented in a desired direction. For example, from here in New England, I prefer to have wire antennas that produce 2 lobes, one to the Northeast (Europe) and the other Southwest (toward the rest of the USA). Significant amounts of gain on antennas that can't be rotated can produce less useful antennas. I do have, and use, a G5RV. It's the compromise antenna that I leave up as a backup to the antennas that DO perform in the desired directions. If I lose an antenna to wind or other weather, the G5RV will radiate sufficiently to not be off the air. Dan From lwbyppp@epix.net Sat Mar 30 14:15:28 1996 Newsgroups: rec.radio.amateur.antenna From: dts@peanut.senie.com (Daniel Senie) Subject: Re: Ignorant question: What's a G5RV??? Message-ID: <4j4vib$fp8@peanut.senie.com> References: <314DC5B9.588F@vertex.ucls.uchicago.edu> <4ils2n$ilh@newsbf02.news.aol.com> <4ioivl$25j@crash.microserve.net> Date: Mon, 25 Mar 1996 02:14:35 GMT In article <4ioivl$25j@crash.microserve.net>, WB3U wrote: > w8jitom@aol.com (W8JI Tom) wrote: > >>Some people hate G5RV's, and "write bad things on walls" about them. >>But they are pretty good antennas for the effort, especially on 80, >>40 and 20 meters. > >Guess I'm one of the graffiti guys, 'cause I still don't understand >what the fuss is all about. In the configuration most people use >these in, they're practically a dummy load on 15 & 10m. The only way >to make this antenna perform well on all the bands is to ditch the >balun and drive it with a balanced tuner. Once you do that, it's just >a plain ole 102' dipole with a low-loss feed system, not a G5RV. I guess I bought the "right" G5RV then, several years ago. The one I have is from Antennas West, and does NOT have a balun. I feed it with coax to the bottom of the ladder line without any direct matching... well sort of. I do have a current balun made of a dozen or so 1" long ferrite beads over the coax. The antenna generally performs acceptably, though not outstandingly, on all bands 80 through 10. It's a good all-around back-up antenna... Dan From lwbyppp@epix.net Sat Mar 30 14:15:30 1996 From: levine@mc.com (Bob Levine) Newsgroups: rec.radio.amateur.antenna Subject: Re: Ignorant question: What's a G5RV??? Date: 21 Mar 1996 19:50:05 GMT Message-ID: <4isbtd$n05@newsy.mc.com> References: <314DC5B9.588F@vertex.ucls.uchicago.edu> Reply-To: levine@mc.com In article <314DC5B9.588F@vertex.ucls.uchicago.edu>, Isaac Kohn writes: -->Subject says it all.... What's a G5RV??? (antenna tuner??) --> -->73's -->Isaac A very famous ham in England. QSL via BURO also a dipole antenna cut to a specific length and fed with (typically) ladder line to make a resonant antenna on 80,40,20,15, and 10m. Some longer versions also work on 160. Usually 26' size 10-15-20m 52' size 10,15,20,40m 105' size 10-80 210' size 160-10 Antennas West makes the best (IMO) and have lifetime guarantees. -- /***************************************************************** * Bob Levine * * Manager of Application Engineering * * Mercury Computer Systems * * Amateur Radio Callsign KD1GG * *****************************************************************/ From lwbyppp@epix.net Sat Mar 30 14:15:31 1996 From: w8jitom@aol.com (W8JI Tom) Newsgroups: rec.radio.amateur.antenna Subject: Re: Ignorant question: What's a G5RV??? Date: 20 Mar 1996 23:40:05 -0500 Message-ID: <4iqmj5$bg0@newsbf02.news.aol.com> References: <4iq1c0$7ca@crash.microserve.net> Hi Jack, Rather than go over everything you said, let's first try to agree about what a choke balun does, and how it functions. We disagree almost completely at this point of time! :-) There are two separate problems a balun must deals with, common mode (like a parallel line excited by a voltage source) and differential mode (like a normal transmission line). Before getting into balun operation, we have to agree that common and differential modes are entirely different parameters, and do not have to be related to each other in any way. In other words, a system can have a low impedance line (high differential currents, low differential voltages) and very high common mode voltages, or vice versa. The common and differential mode voltages can also be nearly the same! They are unrelated except by happenstance or coincidence. If we agree on that, let's also agree what a choke balun is. By choke balun, I mean any balun that has a high common mode impedance, and a differential mode impedance unrelated to it's common mode impedance. Examples include sleeves over coax and solenoid windings of coaxial or two wire lines with either air or ferrous cores. All of the above "choke baluns" function the same way. "Load impedance" doesn't directly affect the choking ability. Normal differential mode excitation does NOT cause magnetic fields to appear in the core material. Common mode load impedance and operating power levels do not cause loss or heating in the choke balun. The only loss is a very small transmission line mode loss in the parallel wires (or coax) used to make the balun, and it is never affected only by the length of the transmission line used to make the balun. The loss is very small line section in a well designed choke balun. Only the common mode voltage (or current) causes core heating and core power loss. Common mode parameters are not directly related to the transmission line Z at the balun. The common mode voltage can be very low with a high Z load, or very high with a low Z load. Because of this, I disagree with most or all of your analysis. 73 Tom From lwbyppp@epix.net Sat Mar 30 14:15:32 1996 From: cmoore@vegas.ch.intel.com (Cecil A. Moore~) Newsgroups: rec.radio.amateur.antenna Subject: Re: Ignorant question: What's a G5RV??? Date: 24 Mar 1996 22:08:16 GMT Distribution: world Message-ID: <4j4h4g$sh1@chnews.ch.intel.com> References: <314DC5B9.588F@vertex.ucls.uchicago.edu> <4ioh6b$25j@crash.microserve.net> <4ips4p$k1c@itnews.sc.intel.com> <4iscvu$g1k@crash.microserve.net> In article <4iscvu$g1k@crash.microserve.net>, WB3U wrote: >Using the variable-length matching sections that you've described (in >conjunction with a balun at the feedpoint), or using a balanced tuner, >perfomance of a 102' dipole could be exceptional ... Guess I'm going to have to design a "G57BK" that has super high efficiency on all HF bands and a 50 ohm SWR of 1:1. I've already done 90% of the design and it works like a charm. It would be easy to turn into an autotuner completely transparent to the operator. The key is the single tuning component is in exactly the right place on the transmission line for maximum efficiency. 73, Cecil, KG7BK, OOTC (not speaking for my employer) From lwbyppp@epix.net Sat Mar 30 14:15:33 1996 From: cmoore@vegas.ch.intel.com (Cecil A. Moore~) Newsgroups: rec.radio.amateur.antenna Subject: Re: Ignorant question: What's a G5RV??? Date: 26 Mar 1996 20:40:56 GMT Distribution: world Message-ID: <4j9koo$14vh@chnews.ch.intel.com> References: <314DC5B9.588F@vertex.ucls.uchicago.edu> <4ioh6b$25j@crash.microserve.net> <4ips4p$k1c@itnews.sc.intel.com> <4j4uqq$fnh@peanut.senie.com> In article <4j4uqq$fnh@peanut.senie.com>, Daniel Senie wrote: > >Those 4 lobes on the G5RV will go at different angles than the >lobes produced on 80 meters, or 20 meters, or whatever. Here in Aridzone, those four lobes allow me to cover Europe, South America, Asia/Pacific, and New Zealand. With a half-wave dipole, I could cover either Europe and New Zealand or South America and Asia/Pacific or be forced to put up two half-wave dipoles or rotate it. One antenna that works well from the West is an 88ft dipole. It's an EDZ on 20m giving broadside 3dbd coverage and has a beautiful 2dbd clover-leaf pattern on 17M to cover everything else except Central Russia and the South Pole. 73, Cecil, KG7BK, OOTC (not speaking for my employer) From lwbyppp@epix.net Sat Mar 30 14:15:34 1996 From: John Fleming Newsgroups: rec.radio.amateur.antenna Subject: Re: Ignorant question: What's a G5RV??? Date: Tue, 26 Mar 1996 15:49:51 +0500 Message-ID: <3157CBCF.699D@mailbox.mcs.net> References: <314DC5B9.588F@vertex.ucls.uchicago.edu> <4ils2n$ilh@newsbf02.news.aol.com> <4ioivl$25j@crash.microserve.net> <4j4vib$fp8@peanut.senie.com> Check out the Antennas West G5RV at: http://www.far.net/antennaswest > > I guess I bought the "right" G5RV then, several years ago. The one I have is > from Antennas West, and does NOT have a balun. I feed it with coax to the > bottom of the ladder line without any direct matching... well sort of. I do > have a current balun made of a dozen or so 1" long ferrite beads over the > coax. The antenna generally performs acceptably, though not outstandingly, > on all bands 80 through 10. It's a good all-around back-up antenna... > > Dan From lwbyppp@epix.net Sat Mar 30 14:15:36 1996 From: levine@mc.com (Bob Levine) Newsgroups: rec.radio.amateur.antenna Subject: Re: Ignorant question: What's a G5RV??? Date: 27 Mar 1996 18:24:11 GMT Message-ID: <4jc14b$c71@newsy.mc.com> References: <4j4vib$fp8@peanut.senie.com> Reply-To: levine@mc.com If you are really interested in G5RVs and all the details, Antennas West has a publication called G5RV Technote. It is about 25 pages and answers a lot of questions. I think the price is $6.95 last time I knew. I used to sell Antennas West products from my Radio Devices business and their stuff is constructed nicely. I dont own that business anymore, but you can email the new owner Rhyne at rhynek@raddev.com for details. Also they are http:\\www.raddev.com\biz\raddev on the WWW. -- /***************************************************************** * Bob Levine * * Manager of Application Engineering * * Mercury Computer Systems KD1GG/VK2GYN/7J1AIS * *****************************************************************/ From lwbyppp@epix.net Sat Mar 30 14:15:36 1996 From: Dave Benzel Newsgroups: rec.radio.amateur.antenna Subject: Improving F/B ratio with lossy dielectric? Date: 28 Mar 1996 21:23:17 GMT Message-ID: <4jf005$1sr@lll-winken.llnl.gov> I am wondering if anyone has experience with improving the front/back ratio of an antenna by placing a lossy dielectric (RF poor plastic) rearward? If so, are there any recomendations as to the type of dielectric and thickness required? Specifically, I have a patch antenna for 900 MHz with a specified F/B ratio of 18 dB, but I need at least 22 dB. I would like to mount the patch (a Cushcraft Data Patch antanna) on a roughtly 16x16 inch sheet of plastic. Thanks - Dave From lwbyppp@epix.net Sat Mar 30 14:15:37 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: Improving F/B ratio with lossy dielectric? Date: Fri, 29 Mar 96 18:49:08 GMT Message-ID: <4jhbnh$esv@crash.microserve.net> References: <4jf005$1sr@lll-winken.llnl.gov> <4jh7j0$pr7@nadine.teleport.com> Dave Benzel wrote: >I am wondering if anyone has experience with improving the front/back >ratio of an antenna by placing a lossy dielectric (RF poor plastic) >rearward? If so, are there any recomendations as to the type of >dielectric and thickness required? I've heard of that being done at 2.5 GHz in order to reduce multipath from reflective objects behind the transmit antenna. Unfortunately, I think the absorptive material was a commercial product made for that purpose (at 2.5 GHz) and that it was expensive. Andrew Corp. or other manufacturers with a good test facility would probably have additional information on this. 73, Jack WB3U From lwbyppp@epix.net Sat Mar 30 14:15:39 1996 From: "E. Wade Thompson" Newsgroups: rec.radio.amateur.antenna Subject: Indoor AM Antenna Question (again) Date: 29 Mar 1996 11:16:57 GMT Message-ID: <4jggr9$88g@ssbunews.ih.att.com> I received 2 responses to my previous post about getting AM reception in the office building I work in. ie. (part of my original post) > I'm asking for suggestions/help on picking up AM stations where I work > (my office in particular). For about 2 years I've been listening to a > Chicago station (WLS, 890) and have had no problem with reception because > my office was close to an outside wall (and window). Unfortunately my boss > made me move to an interior office and now I can't pick up 890 (or any AM > station). I had a cheap radio, so I went looking for a better one with SW > capabilities and an external antenna connection. I settled on a Radio Shack > DX-390 after a lot of looking and even though I think it's probably not the > best, it was the best I could find fairly quickly (I miss WLS). Anyway, it > does no better than my cheap radio, even when I connect to the external > and run it down the hallway almost to the window. I really appreciate it, but unfortunately I can't implement them for a number of reasons (they were to get a low power FM rcvr/xmitter and place my radio near a window). And now I've found out something different. I can get 890 by my office door as long as I keep the radio close to the floor. It's weak and ther e is quite a bit of interference, but the signal is there. So, I've been reading more and more and am trying a new tack. How about a GE Superadio III in combination with a Select-A-Tenna? If anyone thinks this might work can you direct me to where I can find a Select-A-Tenna? I've tried the net and the only link I find to it comes back with an error. If the Select-A-Tenna is as good as I've heard it might work with my 390, but I've more or less decided I'd like to keep it home for the SW. Also again, could you please email to me direct. I'm having problems reading news groups. They seem to be disappearing before I read them and I'm not sure what I've got set wrong. Although if you posted to the group, I might be able to catch it and figure out what I'm doing wrong. Thanks, Wade wthompso@ixstar.ih.att.com From lwbyppp@epix.net Sat Mar 30 14:15:40 1996 From: Eric Newsgroups: alt.radio.scanner,alt.radio.pirate,aus.radio,rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc,rec.radio.scanner,rec.radio.shortwave,uk.radio.amateur Subject: KENWOOD TH415E Date: Wed, 27 Mar 1996 18:57:43 -0100 Message-ID: <31599DB7.7C8F@pacwan.mm-soft.fr> References: <314C74DA.2BB3@shadow.net> <4ijvsq$5ud@postman.jet.uk> <4iu54f$ald@alterdial.UU.NET> <4j2rrd$hee@ccnet2.ccnet.com> I'm looking for the instructions manual of the KENWOOD TH415E UHF FM Transceiver. Could anyone help me ? Thanks, Eric. From lwbyppp@epix.net Sat Mar 30 14:15:42 1996 From: "Ian White, G3SEK" Newsgroups: rec.radio.amateur.antenna Subject: Re: Ladder Line for VHF/UHF Date: Sat, 23 Mar 1996 13:44:07 +0000 Distribution: world Message-ID: References: <4ivp9i$2gs@crash.microserve.net> WB3U wrote: >I've seen a few articles here recently about the use of balanced >line for VHF and UHF transmitting. I just wanted to mention that the >self-cancelling feature of this line is related to its spacing. All >the literature I have says the spacing should be no more than 0.01 >wavelength. > This is not a 'hard' limit - just somebody's idea of the spacing at which losses *might* become significant. It doesn't mean a lot that "all the literature" says the same. It's mostly an indication that the people who write all the ham literature have read all the other literature first :-) The radiation loss is caused by the spatial phase difference between two quite closely spaced conductors carrying equal currents in antiphase. G6XN calls this "W8JK mode" because it's like the close-spaced W8JK flat-top antenna with a 180deg twist in the phasing line. The maximum radiation is bidirectional, sideways in the plane of the transmission line. The power radiated sideways from a balanced line (currents exactly equal and in antiphase) is proportional to: (I - I*cos(S))^2 where I is the current and S is the spacing expressed as an angle, ie 360deg = 1 wavelength. Because cos(S) remains close to 1 for spacings well beyond 0.01wl, this source of radiation loss is negligible. Quoting a different analysis from Terman, G6XN gives the power radiated from a balanced line carrying I amps as: P_r = 160 * (pi * D)^2 * I^2 where D is the spacing as a fraction of a wavelength. [ BTW, this equation has the strange property that P_r is independent of the total length of line. I don't have the 1943 edition of Terman's 'Radio Engineer's Handbook' (not the more common 'Radio Engineering') which G6XN references - can anybody comment, please? ] >The chart below shows what this means in terms of the maximum >allowable distance between conductors: > >Freq (MHz) 0.01 WL (Inches) > 50 2.3616 > 144 0.82 > 222 0.531892 > 420 0.281143 > >This would seem to put a limit on 1" and 3/4" ladder line within the >VHF range, even if loss is acceptable at those frequencies. It depends how you build the line. Straight runs of 200-ohm and 300-ohm line built from #10 enameled copper with the least possible number of PTFE spacers will have losses at 432MHz comparable with half-inch hardline, and far lower than RG213 or 9913. Many moonbouncers have confirmed this - and the spacing required is about 0.4in. Self-supporting open "wire" made from quarter-inch aluminium tubing works even better because it eliminates most of the losses in the spacers and supports. Even though the spacing is as high as 0.75in, the total losses are so low that they're very hard to measure. This is currently the method of choice for interconnecting yagi arrays for moonbounce. 73 from Ian G3SEK Editor, 'The VHF/UHF DX Book' 'In Practice' columnist for RadCom (RSGB) Professionally: IFW Technical Services Clear technical English - anywhere. From lwbyppp@epix.net Sat Mar 30 14:15:43 1996 From: tomb@lsid.hp.com (Tom Bruhns) Newsgroups: rec.radio.amateur.antenna Subject: Re: Ladder Line for VHF/UHF Date: 25 Mar 1996 16:26:52 GMT Distribution: world Message-ID: <4j6hgc$ito@hpcvsnz.cv.hp.com> References: Ian White, G3SEK (G3SEK@ifwtech.demon.co.uk) wrote: : Quoting a different analysis from Terman, G6XN gives the power radiated : from a balanced line carrying I amps as: : P_r = 160 * (pi * D)^2 * I^2 : where D is the spacing as a fraction of a wavelength. : [ BTW, this equation has the strange property that P_r is independent of : the total length of line. I don't have the 1943 edition of Terman's : 'Radio Engineer's Handbook' (not the more common 'Radio Engineering') : which G6XN references - can anybody comment, please? ] From Fredrick Terman, "Radio Engineers' Handbook," 1943, McGraw-Hill, pp 193-194: "Radiation from Transmission Lines.--All transmission lines, except those fo the concentric type, radiate some energy. Such radiation is often of importance, since it represents an additional energy loss, and in the case of transmission lines used in association with directional antennas, may seriously modify the directional pattern of the complete system. "The radiation from a two-wire nonresonant line is given approximately by the following formula, [from Sterba and Feldman, "Transmission Lines for Short Wave Radio Systems," _Proc._I._R._E., Vol 20, p. 1163, July, 1932], provided that the length is at least twenty times the spacing and the spacing is not greater than one-tenth of a wavelength and the line is nonresonant: [TVB: Boy, it must be really important that the line is nonresonant!] Radiated power / I^2 = 160 (pi * D / lambda)^2 (74) [TVB: note the lambda difference from what Ian wrote...but it's just a different def. for D: ] where D/lambda is the spacing in wave lengths, and I is the rms line current. This radiation is twice that resulting from a doublet antenna carrying the same current as the line and ahving a length equal to the line spacing. In addition to the radiation given by Eq. 74, the terminating connections also peoduce radiation, so that the total radiation from the line with its terminations will be approximately four times the power radiated from a doublet having length equal to the line spacing, and carrying the line current." -- Cheers, Tom tomb@lsid.hp.com From lwbyppp@epix.net Sat Mar 30 14:15:44 1996 From: Kevin Schmidt Newsgroups: rec.radio.amateur.antenna Subject: Re: Ladder Line for VHF/UHF Date: 25 Mar 1996 18:32:07 GMT Message-ID: <4j6or7$1e8c@theory.tc.cornell.edu> References: <4ivp9i$2gs@crash.microserve.net> "Ian White, G3SEK" wrote: >The power radiated sideways from a balanced line (currents exactly equal >and in antiphase) is proportional to: > > (I - I*cos(S))^2 > >where I is the current and S is the spacing expressed as an angle, ie >360deg = 1 wavelength. Because cos(S) remains close to 1 for spacings >well beyond 0.01wl, this source of radiation loss is negligible. > >Quoting a different analysis from Terman, G6XN gives the power radiated >from a balanced line carrying I amps as: > > P_r = 160 * (pi * D)^2 * I^2 > >where D is the spacing as a fraction of a wavelength. > >[ BTW, this equation has the strange property that P_r is independent of >the total length of line. I don't have the 1943 edition of Terman's >'Radio Engineer's Handbook' (not the more common 'Radio Engineering') >which G6XN references - can anybody comment, please? ] > This property isn't so strange. The transmission line equations are usually derived by assuming an infinitely long transmission line made of perfect conductors. You find that there is a nonradiating mode that transports energy down the line with both the electric and magnetic fields transverse to the direction of the wires, the TEM mode. Since this is a solution to Maxwell's equations, and the fields die off faster than 1/r as you move away from the conductors, it does not radiate at all. So if you can excite a perfectly straight transmission line by creating the proper TEM mode fields at both ends, you will not have any radiation loss. Generally, the excitation is more like a small generator connected by wires to the transmission line. This then radiates more or less like a small dipole. The radiation is independent of the length because it is an end point effect. A similar thing happens at the load end. You could minimize this loss by exciting a transmission line with the conductors close together and slowly bring them apart (a tapered line) to whatever spacing you wanted to increase the characteristic impedance and lower the loss. You would do the same thing at the load end. In addition anything else that is different from the original assumptions can cause radiation. In particular, if the line bends, you get additional radiation losses which increase with the spacing. If it rains, the bumpy dielectric produced can cause radiation. All of these effects can be estimated, and lead to various rules people have about the spacing. Kevin Schmidt w9cf@ptolemy.la.asu.edu From lwbyppp@epix.net Sat Mar 30 14:15:45 1996 From: ssouva@borg.com (Scott D. Souva) Newsgroups: rec.radio.amateur.antenna Subject: Ladder line length Date: Thu, 28 Mar 1996 13:54:33 GMT Message-ID: <315a982f.6301082@news.borg.com> I'm about to hang a 160 meter dipole and will use 450 ohm ladder line into an antenna tuner. My question is-- how long should the feedline be? I've got 100 feet of the stuff and would like to cut it to an optimal length. If I end up cutting the feedline to a specific length, how should the excess feedline be handled (coiled up...)? Any ideas would be welcome. Scott Souva ssouva@borg.com From lwbyppp@epix.net Sat Mar 30 14:15:46 1996 From: Cecil Moore Newsgroups: rec.radio.amateur.antenna Subject: Re: Ladder line length Date: Fri, 29 Mar 96 00:56:08 -0500 Message-ID: References: <315a982f.6301082@news.borg.com> Wes Stewart writes: >The optimum length is zero. The next best is 265' (1/2 wavelength). >The most practical is the distance between the tuner and the antenna. Hi Wes, there's another choice. Shorten the dipole until the transmission line current maximum is exactly at the transmitter. It's much easier to match that way. 73, Cecil, KG7BK, OOTC From lwbyppp@epix.net Sat Mar 30 14:15:47 1996 From: "Carmine M. Iannace" Newsgroups: rec.radio.amateur.antenna Subject: Re: Ladder line length Date: Fri, 29 Mar 1996 13:22:27 -0500 Message-ID: <315C2A63.53CD@bu.edu> References: <315a982f.6301082@news.borg.com> Scott D. Souva wrote: > > I'm about to hang a 160 meter dipole and will use 450 ohm ladder line > into an antenna tuner. My question is-- how long should the feedline > be? I've got 100 feet of the stuff and would like to cut it to an > optimal length. > > If I end up cutting the feedline to a specific length, how should the > excess feedline be handled (coiled up...)? > > Any ideas would be welcome. > > Scott Souva > ssouva@borg.com I've been licensed since 1982 and have strung up many dipole antennas fed with different types of line. Basically, your idea of feeding the dipole with 450 ohm open wi re line is the best way for multiband use. If your attaching the line to the balanced inp uts of a tuner the lenght of line is, in a practical sense, not important. Just run th e line all the way to the tuner and simply cut off any excess. Be sure to keep the open w ire away from any metal at least twice the distance between the conductors of the line (ie- 1 inch 450 ohm line means that it should be seperated by 2 inches from a gutter, etc.) -- Carmine Iannace KA2PAP The Mountain Top Homepage http://members.aol.com/greeneny From lwbyppp@epix.net Sat Mar 30 14:15:48 1996 From: Tom Lewis Newsgroups: rec.radio.amateur.antenna Subject: Larson 2/70 open coil ant Date: 26 Mar 1996 15:30:53 GMT Message-ID: <4j92jd$255@nntp.flash.net> FYI I recently purchased a Larson 2/70 dual band OPEN COIL antenna for my car. When installed using the larson magmount, I discovered the antenna was resonant above both 2 meters and 70 centimeters! The SWR was 2.2 to one on the lower portion of the VHF band and 1.8 to one on the UHF. I talked with a Larson representative on the phone. He admitted there was a problem with the OPEN COIL stingers and the center frequency being above the ham bands! He then suggested I purchase the closed coil antenna because it was tuned for the center of each band of interest. Anyway, I just wanted to share my experience with everyone. 73! Tom Lewis - AB5CK AB5CK Dopplers Doppler technology - Radio Direction Finding From lwbyppp@epix.net Sat Mar 30 14:15:49 1996 From: bbruhns@newshost.li.net (Bob Bruhns) Newsgroups: rec.radio.amateur.antenna Subject: loop antennas Date: 24 Mar 1996 15:37:51 GMT Message-ID: <4j3q8f$bs3@linet06.li.net> I am getting pretty good results from in the northeast US, from Maine to Virginia, with vertical loops on 75 meters. I use 1/2 wave loops, which start out as 1/2 wave dipoles and then wrap around into a loop shape (ends not connected together). In fact, the ends overlap (again, not touching; a few feet of separation between the ends), making these loops quite compact. This approach requires only one tall support, which also holds the feedlines and baluns. I went one step further, and placed two vertical loops at right angles, and fed them 90 degrees out of phase. This produces circular polarization straight up, although the polarization becomes elliptical at lower angles, and vertical at very low angles. With proper "sense" (which changes with time of day), circular polarization enhances transmission and reception; I get stronger receive signals, and less short-term and selective fading, on local and DX signals. I found it helpful to provide for separate adjustment of TX sense and RX sense; the optimum TX sense setting does not always match the optimum RX setting. It seems that the circular sense of DX is opposite that of closer (500 mile radius) stations. This allows receive antenna polarization sense to provide some discrimination against local interference. Bob Bruhns, WA3WDR, bbruhns@li.net From lwbyppp@epix.net Sat Mar 30 14:15:50 1996 From: Dave Hand Newsgroups: rec.radio.amateur.antenna Subject: Re: loop antennas Date: 27 Mar 1996 13:38:22 GMT Message-ID: <4jbgce$9u7@jeefers.microdes.com> References: <4islis$i4i@opal.southwind.net> <4ja8k7$iub@news.ios.com> robertm@ios.com (robert morgenstern) wrote: > > Lee Buller (k0wa@southwind.net) wrote: > : Hey, has anyone out there have any experience with loop antennas for > : the HF bands? I had a delta loop several years ago on 40 meters and > : it was a good antenna. Is anyone using loops on the new WARC bands? > > : Thanks for any feedback > > : Lee Buller > : k0wa@southwind.net > Lee; > Just look for the formula regarding loop antennas, in the ARRL Handbook > and fabricate one. I had a Delta loop on 20 for a few years and it was F.B. > by all the sig rpts. > Gud luck et 73,s Bob WA2EAW > Lee, I have built several fw loops over the past few years and for the simplicity and cost I dont think you can beat them, they work very well. I much prefer my 40 loop to a long 160 m dipole for op on 40m. I ran one on 17m and was very happy with it untill I put up a beam. The easiest way to feed 'em is 1/4 of 75 ohm coax as a matching stub but you can also gama match em. Good luck! Dave Hand WB4HYP dhand@microdes.com From lwbyppp@epix.net Sat Mar 30 14:15:52 1996 From: Karl_Shepard@ccm.jf.intel.com (Karl Shepard) Newsgroups: rec.radio.amateur.antenna Subject: Loop antennas for short wave reception? Date: Wed, 27 Mar 1996 11:08:34 Message-ID: I am playing with antennas for my Yaesu FRG 100. I have been reading the ARRL antenna handbook and I interested in hearing about experiences with loop antennas. I was considering building a 20 ft 3/4" copper loop with a capacitor/stepper motor at the top for changing resonance. I would mount this on an 8 ft wood post. Will this provide any gain over a dipole hung at less than 1/4 wave of the length (ie, omni-directional)? This past weekend I put together a 96.5 ft half wave dipole hung at about 30 ft for the 60 meter band. It gives me 2-6 dB gain in the 60 meter band over the Radio Shack dipole that I bought. In the 19 meter band I get a little less gain but still better than the RS antenna. In the other bands it is toss up. Sometimes the antenna with the less gain picks up less interferance. The two antennas are connected to a Daiwa antenna switch. I know that I will get greater directionality from a loop, but will it also provide enough gain to be able pick up weak and distant stations? For example, on the 60 meter 1/2 wave dipole, I was able to get La Vox Evangelica in the 60 meter band clearly. This is a 3kw station in Costa Rico (I live west of Portland Oregon). Will a loop perform as well or better? I am looking for an antenna design that is not huge and does not have to be hung over 30 ft and will give good performance. Will a loop do it? Karl_Shepard@ccm.jf.intel.com From lwbyppp@epix.net Sat Mar 30 14:15:53 1996 From: ddenter@nortel.ca (Dean Denter) Newsgroups: rec.radio.amateur.antenna Subject: Re: Mfgrs of 5 ft Stainless Steel Whips? Date: 25 Mar 1996 16:05:42 GMT Message-ID: <4j6g8m$j8v@bcarh8ab.bnr.ca> References: <4itcgt$i69@newsbf02.news.aol.com> Reply-To: ddenter@magi.com In article <31537944.2191@athena.csdco.com>, Richard Kiefer writes: >Like you Zack I have been trying to find a source of whips. Radio Shack >is the best source I have found, and I am unable to determine who their >manufacturer is. Any shop which caters to CB'er also sells 102" whips. >I also found one wholesaler in Denver which carry them. My interest is >in using 102" units, or longer, as end elements for HF Yagi's Have you tried a welding shop or machine shop? I've found a couple that would sell me stainless steel stock, and one that would even order stuff for me (no special orders, it got ordered whenever they did their regular order -- kept the price down that way). The stainless stock seems to be almost as stiff as CB whips, and you don't have to make your element 102" or shorter (most of what I buy is 10-20' lengths Unfortunately, I've moved across the country, and haven't found another shop to do my orders for me (and I haven't got the room to setup the antennas I already have built). regards, Dean. -- Dean Denter work -> ddenter@bnr.ca VA3CDD play -> ddenter@magi.com [[[[[[[[[[[[[[I speak only for myself]]]]]]]]]]]]]] From lwbyppp@epix.net Sat Mar 30 14:15:54 1996 Newsgroups: rec.radio.amateur.antenna From: dgf@netcom.com (David Feldman) Subject: Re: Mfgrs of 5 ft Stainless Steel Whips? Message-ID: References: <4itcgt$i69@newsbf02.news.aol.com> <31537944.2191@athena.csdco.com> <4jca36$2bd@news.inc.net> Date: Wed, 27 Mar 1996 21:54:45 GMT In article <4jca36$2bd@news.inc.net> Will Flor writes: >Richard Kiefer wrote: >>Like you Zack I have been trying to find a source of whips. Radio Shack >>is the best source I have found, and I am unable to determine who their >>manufacturer is. Any shop which caters to CB'er also sells 102" whips. >>I also found one wholesaler in Denver which carry them. My interest is >>in using 102" units, or longer, as end elements for HF Yagi's > >I imagine that for your use, such whips would work well. For those of us who >would like to use them for other purposes, like an end-loaded vertical mobile >antenna - remember, CB antennas are not designed to handle high power levels, >since 12W SSB is max out for a (legal) CB. > >73 de Will KB9JTT I had a need for some longer-than-normal HAMSTICK whips ("stingers"). Lakeview (who makes the HAMSTICK line) supplied several to me (I think they were in the $7 range each). I think they are about 5' long, but I am not certain. They are definately longer than the stock whip, and this permitted my 75M hamstick to cover down through the bottom of the CW portion of the 80M band. Might be worth giving them a call. P.S., I am interested in finding some really long COLLAPSIBLE whips, like were used on 1960's era CB HTs and some older shortwave sets. I asked VOCOM (and one other vendor) who supplied whips for those "5/8 wave" 2M HT whips but they didn't provide any useful info. Any leads? 73 Dave WB0GAZ dgf@netcom.com From lwbyppp@epix.net Sat Mar 30 14:15:55 1996 From: Will Flor Newsgroups: rec.radio.amateur.antenna Subject: Re: Mfgrs of 5 ft Stainless Steel Whips? Date: 27 Mar 1996 20:57:10 GMT Message-ID: <4jca36$2bd@news.inc.net> References: <4itcgt$i69@newsbf02.news.aol.com> <31537944.2191@athena.csdco.com> Richard Kiefer wrote: >Like you Zack I have been trying to find a source of whips. Radio Shack >is the best source I have found, and I am unable to determine who their >manufacturer is. Any shop which caters to CB'er also sells 102" whips. >I also found one wholesaler in Denver which carry them. My interest is >in using 102" units, or longer, as end elements for HF Yagi's I imagine that for your use, such whips would work well. For those of us who would like to use them for other purposes, like an end-loaded vertical mobile antenna - remember, CB antennas are not designed to handle high power levels, since 12W SSB is max out for a (legal) CB. 73 de Will KB9JTT From lwbyppp@epix.net Sat Mar 30 14:15:57 1996 From: davidc@scoot.NETis.COM (David, Michaela & Benjamin) Newsgroups: rec.radio.amateur.antenna Subject: MFJ Multiband Verticals -- comments Date: 26 Mar 96 18:24:34 GMT Message-ID: <01BB1B17.CF3D00E0@dns.netis.com.198.186.186.2> Date: 25 Mar 1996 14:51:52 -0500 From: thomasm910@aol.com (ThomasM910) Subject: MFJ Multiband verticals -- comments? I am considering the 2M thru 80M vertical. Does anyone have any comments on this or its predecessor? Thanks, Tom, AA0UU, THOMASM910@AOL.COM Tom Miller, Mpls., MN Amateur Radio Station AA0UU *** Tom: I have been trying to gather information here on the several differe nt multiband verticals in the same category as the MFJ, but for some reason the posting keeps getting dropped after it shows up just once :-( I have received two positive reports about the MFJ, the most recent one from a Ham who generally doesn't respect the quality of MFJ products. He said the antenna performed as specified, was rugged enough to survive the past winter without guys, and that other Hams have seen it work and then decided to get one as well. Powerful testimony. The GAP Titan has been roundly panned by every Ham who has replied on packet, E-mail, and here as not much better than a dummy load. I did get one good report on the Telex/Hygain DX-88, and one for the Butternut (but several others have said the Butternut is too flimsy for New England). There is supposedly a UniHat vertical out there, but I've been unable to find useful info. There is also the new Cushcraft R-7000 (and the + model for 75/80), but little experience in the field yet. There you have it. Hope this has been helpful. 73, David AA1FA From lwbyppp@epix.net Sat Mar 30 14:15:58 1996 From: thomasm910@aol.com (ThomasM910) Newsgroups: rec.radio.amateur.antenna Subject: MFJ Multiband verticals -- comments? Date: 25 Mar 1996 14:51:52 -0500 Message-ID: <4j6tgo$jqd@newsbf02.news.aol.com> Reply-To: thomasm910@aol.com (ThomasM910) I am considering the 2M thru 80M vertical. Does anyone have any comments on this or its predecessor? Thanks, Tom, AA0UU, THOMASM910@AOL.COM Tom Miller, Mpls., MN Amateur Radio Station AA0UU From lwbyppp@epix.net Sat Mar 30 14:15:59 1996 From: VE4KLM Newsgroups: rec.radio.amateur.antenna Subject: More Stuff on the Sterba Curtain Date: Mon, 25 Mar 1996 09:17:36 -0600 Message-ID: Here is more information for Rick (rikoski@niia.net) that I said I would try to dig up. Hi Rick, My antenna appears as follows : B ------------------ | | A | | A | | ------\/---------- ------/\---------- | C | | | B | | B | | | | | | ------\/---------- <-------- 300 ohm ------ transmatch ----- 50 ohm ------/\---------- <-------- feed ------- for 2 m ------- HT | C | A | | A | | ------------------ B The quarter wave sections are labelled A, the half wave sections are labelled B, The C is the ~ half wave transmission phase lines. Make sure you put one twist in them (for 180 degree shift). The intermod is not there because of the selectivity of the transmatch's tuned circuits. That did not dawn on me in my original response to you. If you want more detail on this antenna, see QST Issue October, 1991, an article by K1TN, 'Curtains for you'. Regards, Maiko Langelaar VE4KLM Winnipeg, Manitoba, Canada --------------------- | SLM Software Inc. | | slmusr03@SLMSoft.CA | --------------------- From lwbyppp@epix.net Sat Mar 30 14:16:00 1996 Newsgroups: rec.radio.amateur.antenna From: hbaker@netcom.com (Henry Baker) Subject: New Megawave TV Antenna on CNN today... Message-ID: Date: Mon, 25 Mar 1996 01:54:37 GMT Has anyone seen the 'Megawave' antenna designed by John & Glenda Benham of Megawave on CNN this weekend?? Upon doing a web search, it would appear that US DOD ARPA is a supporter of this effort. Apparently, a popular science magazine did a story on this, as well, but the track record of this particular magazine isn't very good at telling what actually works and what doesn't. :-) Does anyone know how it works or how well it works? Philips has also developed a 'ghost eliminator' that is supposed to be available right about now. Can anyone compare & contrast? (I have no relationship with Megawave, Philips, or any other vendor, but am just curious as a potential consumer.) Thx in advance for any help in this matter. -- www/ftp directory: ftp://ftp.netcom.com/pub/hb/hbaker/home.html From lwbyppp@epix.net Sat Mar 30 14:16:01 1996 From: watchman@netside.com Newsgroups: rec.radio.amateur.antenna Subject: no tune antenna Date: Tue, 26 Mar 96 18:56:43 GMT Message-ID: <4j8sf1$ioo@nntp.netside.com> can anyone give me info on a no tune antenna for 80-10m. I have a problem with my tuner on my present antenna cut for 3700 khz. Thanks KD4DPB Billy From lwbyppp@epix.net Sat Mar 30 14:16:04 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: no tune antenna Date: Wed, 27 Mar 96 18:59:55 GMT Message-ID: <4jc3j9$ksg@crash.microserve.net> References: <4j8sf1$ioo@nntp.netside.com> watchman@netside.com wrote: >can anyone give me info on a no tune antenna for 80-10m. I have a >problem with my tuner on my present antenna cut for 3700 khz. A trap dipole would fit that description, but I don't know if there's a commercial model that covers all the bands. 73, Jack WB3U From lwbyppp@epix.net Sat Mar 30 14:16:05 1996 From: Dave Hand Newsgroups: rec.radio.amateur.antenna Subject: Re: OK...now i'm mad at the hardline!!!!!! Date: 28 Mar 1996 13:42:15 GMT Message-ID: <4je4vn$4lh@jeefers.microdes.com> References: <4jcgs2$3jlc@ns4-1.CC.Lehigh.EDU> c002@Lehigh.EDU wrote: > > WEll, i did what ALOT of ppl said to do about useing 75ohm hardline > let it go! install pl-259's and use it as is > well...my swr's are down pretty good...but it seems like the cable is > a 100db attenuator!! now what should i do? buy 75-50ohm hardline connector s > from ZD enginerring? or TRY to make one myself? > or have someone send me one for only the cost of shipping > > Sounds like an operator problem ...:) If the hard line is good ( I have seen some here in Fla that is lightning or water damaged) you must have a problem with the ant or the connectors shorts opens ect. If you connected yur pl259 with clip leads it would not cause 100 db loss . The 75 ohm hard line is by nature low loss So Good luck! Dave Hand Wb4hyp From lwbyppp@epix.net Sat Mar 30 14:16:06 1996 From: BOYCRUZ <104152.2610@CompuServe.COM> Newsgroups: phl.media,rec.antiques.radio+phono,rec.radio.amateur.antenna,rec.radio.amateur.digital.misc,rec.radio.amateur.equipment Subject: Popular Commun Free Back Issues Date: 30 Mar 1996 18:04:49 GMT Message-ID: <4jjt41$hsq$2@mhafc.production.compuserve.com> I have around two dozen POPULAR COMMUNICATIONS magazines from the late 1980s years 1987 88 and 89 and have no use for them anymore I would be willing to give these away individually or all together if you want to pay postage Contact me for further info! Lots of articles on shortwave, dxing, radio stations etc From lwbyppp@epix.net Sat Mar 30 14:16:07 1996 From: hansons@mailbag.com (Jason Hanson) Newsgroups: rec.radio.amateur.misc,rec.radio.amateur.antenna Subject: Problem with Indoor HF system Date: Tue, 26 Mar 1996 23:14:43 GMT Message-ID: <4j9tul$lni@grandcanyon.binc.net> Reply-To: hansons@mailbag.com I have an Icom IC-730 HF rig powered by a Pyramid 30A power supply. I have just acquired the MFJ-1621, an indoor/portable antenna with built-in tuning system. I am having a problem however. On most bands, especially 20M, if I try to key the transmitter the transceiver dies completely, just as though the power were shut off. Further, the power supply meters all go to zero. The only thing on the whole system that works is the power supply power light. :) The only way to get anything back to life is to cycle the power on the power supply... I suspect that this is some sort of RF feedback problem - throwing random lengths of wire on the transmitter ground lug does some to help. Does this sound like RF feedback, or something else? What solutions do you recommend? Thanks in advance... From lwbyppp@epix.net Sat Mar 30 14:16:08 1996 From: mkeitz@bev.net (Mike Keitz) Newsgroups: rec.radio.amateur.misc,rec.radio.amateur.antenna Subject: Re: Problem with Indoor HF system Date: 27 Mar 1996 17:31:27 GMT Message-ID: <4jbu1f$ma5@solaris.cc.vt.edu> References: <4j9tul$lni@grandcanyon.binc.net> In article <4j9tul$lni@grandcanyon.binc.net>, hansons@mailbag.com (Jason Hanso n) says: > >I have an Icom IC-730 HF rig powered by a Pyramid 30A power supply. I >have just acquired the MFJ-1621, an indoor/portable antenna with >built-in tuning system. I am having a problem however. > >On most bands, especially 20M, if I try to key the transmitter the >transceiver dies completely, just as though the power were shut off. >Further, the power supply meters all go to zero. The only thing on >the whole system that works is the power supply power light. :) > >The only way to get anything back to life is to cycle the power on the >power supply... The power has indeed been shut off. Most power supplies contain a "crowbar" circuit that fires a SCR to shunt out the output should the voltage rise much above the rated value. This protects your radio from receiving 20-30 V should the regulator in the power supply fail. Most likely, RF is being rectified in the power supply and causing it to regulate improperly, though it is possible that only the crowbar circuit is being fooled. (it would be unwise to simply disconnect the SCR, of course). So the solution is to keep RF away from the power supply. This could be hard to do with an indoor antenna. Obviously, the first measure is to move the antenna as far as possible from the equipment. The cord between the power supply and the radio can act as an antenna. So ideally shorten it (you may not be ready to do that since those cords are expensive) or coil it up to the minimum length possible with setting the power supply right next to or under the radio. Placing ferrite cores on the power lead and the antenna coax may help too. Now that the supply and the radio are right next to each other, bond them together with a grounding strap. Try putting a capacitor (0.01 - 0.1 uF disc) across the output terminals of the supply, or even better a group of 3 capacitors in a triangle from the two ouput terminals and the supply case. If none of this helps, try operating from a 12V lead-acid battery instead of the power supply. This may uncover other problems, such as RF getting into the microphone cord or on the radio case (the knobs feel "hot"). If that is the case, better grounding or otherwise trapping RF from getting back onto the outside of the coax is in order. It is tough to get a good ground in an apartment situation which I assume you have. -Mike KD4QDM From lwbyppp@epix.net Sat Mar 30 14:16:09 1996 From: aga@ssguest.west.sun.com (Tony Angerame - Sun SSE) Newsgroups: rec.radio.amateur.antenna Subject: Quagi Question Date: 27 Mar 1996 17:31:22 GMT Distribution: world Message-ID: <4jbu1a$58i@newsworthy.West.Sun.COM> Reply-To: aga@ssguest.west.sun.com I've decided to use a circular polarized Quagi for the 2 meter OSCAR downlink. I've reviewed several articles all of them excellent but have not come across one s imple fact. Is the distance between elements measured center to center?? It would ap pear that it is but it's just a guess on my part. Since a measurement error of only 1/8" is significant to performance I'd rather not take a chance. Yagi dimensions ce nter to center?? TIA Tony WA6LZH From lwbyppp@epix.net Sat Mar 30 14:16:10 1996 From: Jack Swift Newsgroups: rec.radio.amateur.antenna Subject: Re: Question, where can I find ..... Date: 21 Mar 1996 13:21:09 GMT Message-ID: <4irl45$n70@btc1.up.net> References: <31500063.1BA4@fast.net> To: n2mga@fast.net Try any True Value Hardware.... the SKU number is 139527 for a 40" ($11) and 139535 for a 48" ($12) Jay wrote: >Can anyone suggest where I might be able to buy a piece of hardware used >for anchoring guy wires call an "Earth Screw"? It kinda looks like an >auger that can be turned into the ground with an eyeloop on the end for >attaching guy wires to. > >Tnx in advance for any suggestions etc... > >Jay n2mga@fast.net ------------------------------------------------------------------------- Jack Swift jswift@up.net N8WAV@W8YY.#UPMI.MI.USA.NOAM Swift True Value Hardware 402 Shelden Ave. Houghton, MI 49931 906-482-0530, 0531, 7766 Alpha Phi Omega Epsilon Lambda Chapter Advisor Houghton County Amateur Radio Emergency Service Dereliction IS! Keweenaw Peninsula Chapter American Red Cross CIO/Treasurer Ham It Up! ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ From lwbyppp@epix.net Sat Mar 30 14:16:12 1996 From: rice@ttd.teradyne.com (John Rice) Newsgroups: rec.radio.amateur.antenna Subject: Re: Question, where can I find ..... Date: 24 Mar 96 15:52:18 CDT Message-ID: <1996Mar24.155218.1@ttd.teradyne.com> References: <31500063.1BA4@fast.net> In article , rikoski@niia.net (Rick R ikoski) writes: > In article <31500063.1BA4@fast.net>, Jay wrote: > >> Can anyone suggest where I might be able to buy a piece of hardware used >> for anchoring guy wires call an "Earth Screw"? It kinda looks like an >> auger that can be turned into the ground with an eyeloop on the end for >> attaching guy wires to. >> >> Tnx in advance for any suggestions etc... >> >> Jay n2mga@fast.net > > ===================================== > > Uh well Jay your neighborhood pet store probably has some pretty > substantial screw anchors for leashing dogs to one's back yard. > > If its solid enough to hold a Rottwiler (a dynamic load).Three or four of > em should be able to anchor your antenna guys. Actually, that's not a good analogy. A 'Rott' is going to pull latterally (sideways) and is highly unlikely to pull an anchor out of the ground, from the end of a 15-20' tether, unless it's a 'wire type' screw anchor and only a couple of feet into the ground. (Common design for 'Pet' anchors. I have, however seen a Great Dane 'unscrew' a 3' 'solid' anchor :-). An anchor used to guy a tower, on the other hand, is going to have most of the strain directly upward and be much more susceptable to being pulled out of the ground. I've found them in ACE and TRUE-VALUE hardware stores. They're used, among other things, to anchor House Trailers to the ground, in wind-prone areas (read "the south during hurricane season), but I've found them in the Chicago area, also. I used 4' anchors, in sand, in Florida on a 50' Rohn and went through some 70kt winds with no problems. -------- John Rice - K9IJ | "I speak for myself, not my employer". k9ij@avsoft.com | Miracles, Magic and Sleight-of-hand done here. k9ij@amsat.org | Licensed since 1959 (708)-438-5065 - (bbs ) | Ex: K8YZR, KH6GHC, WB9CSP, W9MMB, WA1TXV From lwbyppp@epix.net Sat Mar 30 14:16:13 1996 From: dragonsl@scn.org (Ralph Lindberg & Ellen Winnie) Newsgroups: rec.radio.amateur.antenna Subject: Re: R7000+ Date: Sun, 24 Mar 1996 08:28:03 -0700 Message-ID: References: <9603140447.AA10820@snipe.dwe.co.kr> In article <9603140447.AA10820@snipe.dwe.co.kr>, zeisu@snipe.dwe.co.KR (Jae-Soo Yoon) wrote: >Has anybody had experiences with Cushcraft's new vertical R7000+? >R7000 looks basically the same as R7 with some improvements. >R7000+ is R7000 with optional 80M add-on. My current antenna >covers 40-20-15-10 and I want to work on 80-30-17-12 in addition. >R7000+ seems to be a good candidate if performance is good. Sorry I can't be of much help, I have the R-7 and think it's worth the money. I have been trying to find out more about the R7000 but their published email address has been bad . They also have a homepage -- Ralph Lindberg N7BSN e-mail to dragonsl@scn.org (read daily) RV and Camping FAQ I am researching this book: Rockwell-Collins, Engineering Compendium: HF Antenna Selection, 1969. Please reply in the news group or by mail ( my adress is in the 1996 Call Book). 73, jacques. From lwbyppp@epix.net Sat Mar 30 14:16:15 1996 From: diagonal@mail.unisoft.fr (Diagonal Cafe) Newsgroups: rec.radio.amateur.antenna Subject: Research for book(II) Date: Fri, 22 Mar 1996 17:55:03 GMT Message-ID: <4iupje$qrm@s3.iway.fr> My call sign is F5ULS 73, jacques Espiau From lwbyppp@epix.net Sat Mar 30 14:16:15 1996 From: kk5ep@aol.com (KK5EP) Newsgroups: rec.radio.amateur.antenna Subject: Rohn 45g and the accessories Date: 27 Mar 1996 16:22:35 -0500 Message-ID: <4jcbir$ham@newsbf02.news.aol.com> Reply-To: kk5ep@aol.com (KK5EP) Hello, I'm in the process of moving from Jackson, MS to Baton Rouge, LA where no tower restrictions exist! I need to purchase some Rohn 45 sections and would like to get around paying full new price if at all possible. Does anyone know of any sources for used Rohn 45g? I have a truck and will travel! 73, Mike Causey KK5EP. From lwbyppp@epix.net Sat Mar 30 14:16:16 1996 From: BColenso@aol.COM Newsgroups: rec.radio.amateur.antenna Subject: roof saftey Date: 23 Mar 96 07:09:42 GMT Message-ID: <960322202005_452631253@emout08.mail.aol.com> In a message dated 96-03-22 11:09:11 EST, Karl Kurz wrote: > >When I was younger a piece of line tossed over the peak and fastened on >the other side to a car or tree worked fine, as I get older I tend to use >my roof jacks to make a steady platform, better yet find a friendly >lineman who will set it up with his hydraulic basket. > >Good Luck When fastening to a car, ALWAYS make sure you have the coil wire in your pocket!! Bob KD8WU Any day ABOVE ground is a GOOD day!! From lwbyppp@epix.net Sat Mar 30 14:16:17 1996 From: Art Gunderson Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.equipment Subject: Re: Seeking Power mobile antenna raise/lower mounting. Date: Wed, 27 Mar 1996 17:04:34 -0800 Message-ID: <3159E5A2.5F46@west.net> References: <4iv1mq$n4a@acmey.gatech.edu> <4j4fev$ars@dfw-ixnews4.ix.netcom.com> Brian Dunlap wrote: > > A friend of mine has mentioned that Motorola still does or used > to manufacture a power Tx/Rx antenna for mobile installation! > > de Brian N9ROVHey Brian, I am assumming you are talking about a powered antenna as in up-down retractable. If so a company named Stico will modify any powered antenna to be a dual purpose Am-Fm and Vhf or Uhf antenna which is functional and still goes up and down. They can be located at 716-662-2680. They usually require you to remove your existing antenna and send it to them. They modify it and return it to you.. You will need a splitter to connect the Am-Fm and the Vhf radios to the same coax. Ask them about it.. good luck. Art WB6VKR -- 73's Art WB6VKR From lwbyppp@epix.net Sat Mar 30 14:16:18 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Sorry, Just a Test - Don't Read Date: Mon, 25 Mar 96 19:29:16 GMT Message-ID: <4j6shl$8k@crash.microserve.net> References: <19960322.094220.22@southlin.demon.co.uk> <4iueis$qed@newsbf02.news.aol.com> <4ivh45$tc@crash.microserve.net> Sample Text > < > < > < > < End From lwbyppp@epix.net Sat Mar 30 14:16:19 1996 From: w8jitom@aol.com (W8JI Tom) Newsgroups: rec.radio.amateur.antenna Subject: Re: Sturba Curtain Date: 24 Mar 1996 11:18:05 -0500 Message-ID: <4j3sjt$jgr@newsbf02.news.aol.com> References: In article , rikoski@niia.net (Rick Rikoski) writes: > >(I think I like antennas like this one because they provide spacial >diversity whereas a log periodic or wideband yagi doesn't) The Curtain doesn't provide more spacial diversity or "capture area" than log's or yagi's having the same gain provide. Effective apature is related to gain, not physical size. Besides that, space diversity is not useful unless special combining techniques are used. Spacial diversity causes as much fading as it eliminates! Other than that, curtains do work quite well. The large Finco VHF (only) antenna had more gain than other antennas available at that time. We used them in Toledo Ohio to receive fringe Detroit and Cleveland stations before TV receivers had low noise front ends. They were the "hottest" antenna around! But the Finco was not a "Sturba" (Sterba), it was a curtain array. A combination of stacked collinear elements with a reflector. Professional antenna engineering textbooks discuss curtain arrays in detail. Cushcraft made a similar two meter antenna. 73 Tom From lwbyppp@epix.net Sat Mar 30 14:16:20 1996 From: Ian Cummings <102152.1703@CompuServe.COM> Newsgroups: rec.radio.amateur.antenna Subject: Re: Sturba Curtain Date: 26 Mar 1996 16:32:48 GMT Message-ID: <4j967g$7ig$1@mhafc.production.compuserve.com> References: <1996Mar20.024224.20673@ke4zv.atl.ga.us> Hi, I put up a Sterba on 15M following a QST article a few years ago. Strung between 2 poles 50 feet high on each side. It had 10 elements if I recall correctly. Beautiful north south (it's orientation) propogation but very narrow beam and narrow bandwidth. I am now playing with fixed quads (10 elements on 20M) beaming my favorite directions (Europe, Equatorial Africa, Pacific and JA, if I get that ambitious and if it works). 73's Ian KB1SG -- Ian Cummings, KB1SG From lwbyppp@epix.net Sat Mar 30 14:16:23 1996 From: w8jitom@aol.com (W8JI Tom) Newsgroups: rec.radio.amateur.antenna Subject: Re: Sturba Curtain Date: 26 Mar 1996 16:34:47 -0500 Message-ID: <4j9ntn$ieu@newsbf02.news.aol.com> References: <4j967g$7ig$1@mhafc.production.compuserve.com> Hi Rick, First let's be sure we agree the frontal area of an array has no direct relationship to capture area or effective aperture. An antenna's effective area or aperture is A= lamda sqrd times gain/ 4pi. (Gain is the directivity times the efficiency of the array.) If we agree on that, we can ignore misused and abused buzz words like "capture area". In a message dated 96-03-26 09:28:27 EST, you write: >1. In a fading situation with both groundwave and skywave, both the phase >and pathlength of the skywave are changing continuously. Most of the time >when the amplitude is sufficient, the effects of these changes in the >skywave are noticed only as destructive cancellation of the groundwave. >Planar antennas such as the log periodic have no defense against this >while the stacked antennas do because the wavefront of the skywave coming >in at an angle arrives at different times at each of the individual >stacked antennas. More frontal area can NOT "cure" fading if phase and amplitude of wavefronts are random. The signal will be in or out of phase just as often with a large frontal antenna as in a small frontal antenna! If the phase relationship is constant, then we only need to design a system of fixed antennas combined with the right phase. The spacial phase relationship is never so simple as occurs in a stack of in-phase elements, unless the signal is a plane wave. When the signal suffers from random phase interference, both systems offer the same performance incentives. In either case, a yagi "works" as well as a broadside array! All diversity systems employ some means of dynamically adjjusting the system to provide the best S/N ratio at any given moment in time. It is all but impossible to reduce fading without detecting random phase shift in multi-path signals, and compensating for it dynamically. Improving directivity by focusing only on the direct wave or a steady indirect wave can help, but an end-fire array is every bit as effective as a broadside or collinear array in focusing. >2. At UHF, especially noticable on television, there are "hot spots" which >are regular places at regular distances above ground where the received >signal can be as much as 6 to 9 db better than at other spots. So if one >aligns a UHF log periodic in a spot which is optimal say for channel 22, >probably the reception on channels 16 or 34 won't be optimal. The >bedspring or 4 or 8 stack bowtie allows for a driven element to be placed >in a hot spot for all of the received channels and thus performs better >than the log periodic. The likelyhood of signal improvement because more elements "land in a hot spot" with a taller stack is untrue in nearly every case. A stack may improve things if the "hot spots" (or more appropriately the *nulls*) result from wave interference immediately in front of the array (in the near field). But most "hot spots" (nulls) occur from random phase arrivial of multiple interfering wavefronts. That effect changes not only with height, but with distance and side movement of the antenna! The null location also changes with frequency, and with other effects such as ducting, or movement of objects between the source and receiving antennas. In the common situation, either a stacked antenna, collinear antenna, or end fire antenna is just as likely to have "dead spots" or fading. Moving the antenna back and forth, or side to side, changes the signal level just as up or down movement will! If you don't beleive that, roll your car forward or to the side at a light when the radio fades! It's just as effective (and less troublesome) as jacking the car up to eliminate the fade! >I suppose "special combining techniques" would be useful but even if you >don't bother, the effect can be seen. For example a garden variety 8 bow >tie with screen reflector Channel Master gives better overall broadband >UHF fringe area reception than any UHF log periodic or corner reflector >antenna that I have tried. Only because the directive gain is higher! The corner reflector has a broad "frontal area", it should support your theory. Why isn't it just as effective? >Parabolic reflector antennas work well in a broadband situation too. >Since they average signals over a variety of heights above ground they >perform well for exactly the same reason that the diversity array does. Again if the wavefront is subject to multiple path arrivals of random phase, the size makes no difference except as it affects gain. If wavefront phase is shifting with height, you can be assured it is shifting with depth or side movement. It all goes back to effective aperture! >Do you know: If Finco is still in business; if so do they still sell the >colinear? If not is it possible to get the design of that antenna? (I >don't mind cutting quarter inch copper tubing) So far as I know, they're long gone. As technology changed and other UHF antennas improved, the mattress and stacked bowtie arrays went away! 73 Tom From lwbyppp@epix.net Sat Mar 30 14:16:23 1996 From: benda@netvision.net.il (Shlomo) Newsgroups: rec.radio.amateur.antenna Subject: Re: this is a test Date: Thu, 28 Mar 1996 13:17:40 GMT Message-ID: <4je4ue$rg4@news.NetVision.net.il> References: <4je4n9$rg4@news.NetVision.net.il> benda@netvision.net.il (Shlomo) wrote: >this is only a test.זהו רק ניסיון זה עוד ניסיון From lwbyppp@epix.net Sat Mar 30 14:16:24 1996 From: benda@netvision.net.il (Shlomo) Newsgroups: rec.radio.amateur.antenna Subject: this is a test Date: Thu, 28 Mar 1996 13:13:51 GMT Message-ID: <4je4n9$rg4@news.NetVision.net.il> this is only a test.זהו רק ניסיון From lwbyppp@epix.net Sat Mar 30 14:16:26 1996 From: w5robert@blkbox.COM (Robert) Newsgroups: rec.radio.amateur.antenna Subject: Tower Paint (fwd) Date: 26 Mar 96 01:47:43 GMT Message-ID: <9603251947.aa24484@blkbox.COM> Forwarded message: From ve7tcp.ampr.org!lyndon Mon Mar 25 16:51:22 1996 From: "Goggans, Steve" To: Dx-Reflecter Subject: Tower Paint Date: Mon, 25 Mar 96 11:11:00 est Message-ID: <3156C531@SMTPGW01.SCH.GE.COM> Encoding: 30 TEXT X-Mailer: Microsoft Mail V3.0 Sender: owner-dx@ve7tcp.ampr.org Precedence: bulk Reply-To: "Goggans, Steve" X-VE7TCP-Loop-Detector: dx "Goggans, Steve" I painted my Roan 25 with an off green water based paint (WEATHERBEATER house and trim) I got from Sears surplus store. Now the fun part. I sat the sections on 2X4 and painted with a regular pump up garden sprayer. I added enough water to the paint it would spray and adjusted the nozzle for a small pattern. I sprayed what I could, rolled the sections when dry and sprayed the other side. This gave me a mottled effect of different densities of green and blends into the woods quite well. As an added benefit my hands or gloved relay GRIP the tower legs. I had new tower sections and did no preparation what so ever, I live in rainy windy Seattle WA area. The tower has been up for about 15 years and the paint is still almost as good as when first sprayed. There a few chips here and there but it just helps with the blending into the forest. I know the normal thing would have been to hit the Galvanizing with something like vinegar to neutralize it first, then a primer, and then the final coat. That is not what I did. I just put the paint in the sprayer, added enough water to get it to spray and sloshed the sprayer while I sprayed. My luck was great and the effect was what I wanted. It has been zero maintenance since a neighbor and I erected it. My hands or gloved still grip the tower much better than the slick unpainted towers I climb for others. Good luck Steve K7LZJ ------- Forwarded via the Internet DX Mailing List. Submissions: dx@ve7tcp.ampr.org Subscribe/unsubscribe requests: dx-REQUEST@ve7tcp.ampr.org DX info on the Web: http://ve7tcp.ampr.org/DX/ -- 73 Robert WB5CRG w5robert@blkbox.com From lwbyppp@epix.net Sat Mar 30 14:16:27 1996 From: w8jitom@aol.com (W8JI Tom) Newsgroups: rec.radio.amateur.antenna Subject: Tribander trap loss Date: 24 Mar 1996 11:18:15 -0500 Message-ID: <4j3sk7$jh0@newsbf02.news.aol.com> References: <4j1p2l$tqs@squick.apana.org.au> >Adds for triband beams promise nearly 6db of gain but how much power is >lost in the traps? Probably not very much. If there was a lot of loss, the traps would melt at fairly low power. For example if the loss was 3dB, at 1500 watts the traps would be dissipating 750 watts. With six traps that would be 125 watts of heat in each trap. But we also know the lss isn't equal in each trap, it's highest in the driven element. So the poor traps in the driven element might have 200 watts or more dissipation in each trap. No way could that happen and the molded plastic trap live long!!! Traps certainly add loss, but so does any multi-banding system. If we really want to "come down on ads", we should get down on the ones that call traps "lossy" and then go on to describe the virtues of something that is even more lossy, like coaxial stubs or folded up linear loading systems! >They usually have at least 6 traps and I'm sure they >aren't lossless. Neither is "linear loading", as a matter of fact it is usually more lossy than a trap!!!!!! (I'm not speaking of stub decoupling with well constructed parallel stubs, although there is some loss involved there also.) > I would think this would be of concern when comparing a >trap beam to a quad. I would think the very THIN wire used to make a quad would also be a problem. Also the pure numbers involved. A single quad element has a little gain (less tha 2 dB) over a dipole in freespace. But when the horizontally polarized quad element is placed near earth (or another groundplane) that advantage in gain drops. At some heights over some ground conditions, the quad's advantage can go completely away, the dipole can provide more gain! As elements are added the difference drops also. Someone actually measured the gain of quads over yagis in an extensive test. They took a crank up tower and a two element tribander to other Hams houses, and did actual FS comparisons. As I recall, the best antennas were monoband yagis, they handily beat multi-element quads of the same boomlength. Two element monoband quads roughly tied small three element trap yagis like TA-33's. I think the article was written by Wayne Overbeck N6NB? (or something like that), and appeared in QST in the 80's. Anyone remember it? It makes good reding and is supported by fact. As further examples, look at the VHF antenna gain shootouts and commercial point to point antenna installations. Not many quads place well in shootouts, and point to point commercial installations never use quads. 73 Tom From lwbyppp@epix.net Sat Mar 30 14:16:28 1996 From: cmoore@vegas.ch.intel.com (Cecil A. Moore~) Newsgroups: rec.radio.amateur.antenna Subject: Re: Tribander trap loss? Date: 26 Mar 1996 19:08:10 GMT Distribution: world Message-ID: <4j9faq$165q@chnews.ch.intel.com> References: <4j543u$4m6@newsbf02.news.aol.com> <4j58ag$6ig@newsbf02.news.aol.com> In article <4j58ag$6ig@newsbf02.news.aol.com>, W8JI Tom wrote: >Traps certainly add loss, but so does any multi-banding system. Hi Tom, I'm working on an approach that switches in 0-15 ft. of ladder-line 25 ft. from a 102 ft. dipole. Given the variable length line, all that is needed to perfectly tune the antenna system is a single parallel variable capacitor (remotely tuned). This is the least lossy matching system that I can think of for an all band HF dipole. What do you (and anybody else) think? 73, Cecil, KG7BK, OOTC (not speaking for my employer) From lwbyppp@epix.net Sat Mar 30 14:16:29 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: Tribander trap loss? Date: Tue, 26 Mar 96 00:31:52 GMT Message-ID: <4j7e97$349@crash.microserve.net> References: <4j543u$4m6@newsbf02.news.aol.com> parf@aol.com (Parf) wrote: >The real loss is in the fact that the parasite spacing is a >compromise for all the bands perhaps except one. Has anyone ever done any tests on a 2 or 3-element yagi with V-shaped elements? In other words, the driven element would be straight, the reflector would be swept back and the director would be swept forward. Wouldn't that provide variable spacing as the traps "open" and "close" on the different bands? 73, Jack WB3U From lwbyppp@epix.net Sat Mar 30 14:16:30 1996 From: parf@aol.com (Parf) Newsgroups: rec.radio.amateur.antenna Subject: Re: Tribander trap loss? Date: 27 Mar 1996 01:52:34 -0500 Message-ID: <4jaoji$2u2@newsbf02.news.aol.com> References: <4j91oi$b6r@newsbf02.news.aol.com> Reply-To: parf@aol.com (Parf) Hi Tom, I agree w/ the 'bones to pick'. How does Cushcraft achieve the same dBD gain on their 6EL 6M yagi (20' boom) as the guys at M Square get out of their 32'(?) 6EL? Are the guys at M Square just dumb? Or are they a little less influenced by the marketing department? I think the latter. Dale WA2YPY From lwbyppp@epix.net Sat Mar 30 14:16:31 1996 From: parf@aol.com (Parf) Newsgroups: rec.radio.amateur.antenna Subject: Re: Tribander trap loss? Date: 27 Mar 1996 01:39:32 -0500 Message-ID: <4janr4$2l5@newsbf02.news.aol.com> References: <4j7e97$349@crash.microserve.net> Reply-To: parf@aol.com (Parf) Hi Jack, The swept idea looks good at 1st blush but the current loop of each element (center of a 1/2 wave) still remains at the same fixed distance. The best that has been done is to add a second director for the highest band (10M in the case of a triband) to adjust for what turns out to be too wide a DE to D1 spacing. This then results in a 3EL on 20M,15M and 4 on 10. Fortunately, the gain VS spacing curves are relatively broad. It is the F/B curves that are narrow. I constantly here hams speaking of the nice broad VSWR curve of their long Yagis- this is probably the least important parameter ( but the most easily measured). The Gain and F/B as well as sidelobe patterns fall apart way b4 the VSWR curve begins to look bad. In fact I am very suspicious of wide VSWR plots- time to check the feedline and connex! Dale WA2YPY From lwbyppp@epix.net Sat Mar 30 14:16:32 1996 From: wvanho@infinet.com (W. E. Van Horne) Newsgroups: rec.radio.amateur.antenna Subject: Tribander Traps Date: 28 Mar 1996 13:50:18 GMT Message-ID: <4je5eq$9t5@news1.infinet.com> There has been a recent discussion of power loss in tribander traps. The discussion missed one point: tribander traps are NOT resonant at any of the operating frequencies. Anyone who reads most ham antenna literature, e.g. the ARRL Antenna Book, gets the impression that all multiband dipoles operate on the "classic trap" basis. In other words, the center wire is cut to resonance at the highest frequency and a trap resonant at that frequency is inserted at each end to "cut it off" when operating that band. Then the next piece of wire at each end is tuned to the next lower band, and similar traps inserted, etc. But I believe all commercial antennas work in a different manner. It is obvious when one looks at the fact that many commercial designs put two traps, side-by-side, in the same housing. Also, note the fact that Butternut verticals have all their traps at the bottom. (Almost all patents that have ever been issued for trap antennas were assigned to Butternut!) The principle of non-resonant "traps" has been explained by Yardley Beers - W0JF in several articles over the last 10-years, or so. See, for example, "Designing Trap Antennas: A New Approach" in HAM RADIO, August, 1987. Also, I believe it is explained in some of Butternut's literature. 73, Van - W8UOF wvanho@infinet.com From lwbyppp@epix.net Sat Mar 30 14:16:33 1996 From: "Dave J. Cook" Newsgroups: alt.radio.scanner,alt.radio.pirate,aus.radio,rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc,rec.radio.scanner,rec.radio.shortwave,uk.radio.amateur Subject: was Re: ####, my FM-25 is ######! What to do?? Date: 25 Mar 1996 04:57:21 GMT Message-ID: <4j593h$dtq@dsm6.dsmnet.com> References: <314C74DA.2BB3@shadow.net> <4iruql$66n@mars.spaceworks.com> <4itlar$3pd@tube.news.pipex.net> <31548C17.6F65B43E@sinister.com> <4j4cei$j3h@news.bellglobal.com> PUNT. From lwbyppp@epix.net Sat Mar 30 14:16:34 1996 Newsgroups: alt.radio.scanner,alt.radio.pirate,rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc,rec.radio.scanner,rec.radio.shortwave,uk.radio.amateur From: gary@ke4zv.atl.ga.us (Gary Coffman) Subject: Re: Weird Radio Problem Message-ID: <1996Mar23.142115.8973@ke4zv.atl.ga.us> Reply-To: gary@ke4zv.atl.ga.us (Gary Coffman) References: <314D9822.371D@vertex.ucls.uchicago.edu> Date: Sat, 23 Mar 1996 14:21:15 GMT In article <314D9822.371D@vertex.ucls.uchicago.edu> Isaac Kohn writes: >Michael J Wooding wrote: >> In article <4idjm1$f0c@madeline.INS.CWRU.Edu>, David Mark >> writes >> >What's happening is your radio is probably tuned to an FM station >> >near the upper end of the band (around 107-108mhz) and you're >> >probably under a flight path. When a plane is nearby (there's >> >that word again) and the pilot transmits on one of the lower >> >airline frequencies, your radio's less than discriminating tuner >> >picks it up.There is a small, minor detail: Air transmissions were AM, las t time I >checked! How does an FM receiver with poor-selectivity receive AM >transmissions??? Remember that the poor selectivity is in the receiver front end, allowing the image signal into the receiver. This doesn't have anything to do with IF selectivity. Now as to how an FM receiver can demodulate AM, if the receiver uses a discriminator, it will happily demodulate AM too unless the signal is strong enough to have it's amplitude variations stripped off by the limiter stage. If the receiver uses a ratio detector, it won't have a limiter because a ratio detector is theoretically insensitive to AM variations. But if the ratio detector isn't perfectly balanced, it will still demodulate the AM signal too. So either of the popular types of FM detector can demodulate AM under the right conditions. One of those conditions is likely to exist in a cheaply made FM receiver using a whip antenna. Gary -- Gary Coffman KE4ZV | You make it, | Due to provider problems Destructive Testing Systems | we break it. | with previous uucp address es 534 Shannon Way | Guaranteed! | Email to ke4zv@radio.org Lawrenceville, GA 30244 | | From lwbyppp@epix.net Sat Mar 30 14:16:36 1996 From: Kevin Schmidt Newsgroups: rec.radio.amateur.antenna Subject: What is a current node Date: 26 Mar 1996 18:35:12 GMT Message-ID: <4j9dd0$vsh@theory.tc.cornell.edu> In physics and mathematics, nodes, when referring to vibrating systems, are the places where no vibration takes place. For example for a square drum head, there is a mode where the nodal lines form an X. You can see the nodes if you sprinkle powder on the drum, and then strike it in a way that excites that mode. Here on rec.radio.amateur.antenna, I see references to "current nodes." On an antenna, I would infer that that is a place where the current is zero or nearly so. I therefore assume, perhaps incorrectly, that it must refer to a current minimum (and therefore a voltage maximum) when talking about a current node on a transmission line. Here the common use for "current node" seem to be for positions along a transmission line where the current magnitude is a maximum and the voltage is a minimum. Which is correct? By the way, I believe the word node comes from latin for knot. Kevin Schmidt w9cf@ptolemy.la.asu.edu From lwbyppp@epix.net Sat Mar 30 14:16:37 1996 From: Cecil Moore Newsgroups: rec.radio.amateur.antenna Subject: Re: What is a current node Date: Tue, 26 Mar 96 21:30:30 -0500 Message-ID: References: <4j9dd0$vsh@theory.tc.cornell.edu> Kevin Schmidt writes: >Here the common use for "current node" seem to be for positions along a >transmission line where the current magnitude is a maximum and the >voltage is a minimum. Hi Kevin, I believe a "node" is defined as a point where the sign of the slope changes. Current nodes are the points where the forward and reflected currents add to a maximum. Voltage nodes are the points where the forward and reflected voltages add to a maximum. The sum of the currents is minimum at a voltage node and the sum of the voltages is minimum at a current node. Current nodes are relatively low resistance while voltage nodes are relatively high resistance. 73, Cecil, KG7BK, OOTC From lwbyppp@epix.net Sat Mar 30 14:16:38 1996 From: Cecil Moore Newsgroups: rec.radio.amateur.antenna Subject: Re: What is a current node Date: Wed, 27 Mar 96 00:18:16 -0500 Message-ID: References: <4j9dd0$vsh@theory.tc.cornell.edu> Cecil Moore writes: >Hi Kevin, I believe a "node" is defined as a point where the sign >of the slope changes. Current nodes are the points where the forward I stand corrected. What I said is true for geometry but not for physics. In physics, a node is a minima. Hey, whadda expect from an old geometry teacher? 73, Cecil, KG7BK, OOTC From lwbyppp@epix.net Sat Mar 30 14:16:39 1996 From: cmoore@vegas.ch.intel.com (Cecil A. Moore~) Newsgroups: rec.radio.amateur.antenna Subject: Re: What is a current node Date: 28 Mar 1996 21:43:53 GMT Distribution: world Message-ID: <4jf16p$9v4@chnews.ch.intel.com> References: <4jaov0$32s@newsbf02.news.aol.com> In article <4jaov0$32s@newsbf02.news.aol.com>, Parf wrote: >Nodes are points of minima- whether voltage or current and occur 1/4 wave >from current or voltage loops (maxima). Loops are also known as antinodes. From lwbyppp@epix.net Sat Mar 30 14:16:40 1996 From: hamop@aztec.asu.edu (CHARLES J. MICHAELS) Newsgroups: rec.radio.amateur.antenna Subject: What's a G5RV Date: 29 Mar 1996 06:51:58 GMT Message-ID: <4jg1ae$gom@news.asu.edu> Wouldn't this thread be simpler if it is recognized that a *G5RV* is a 102 foot antenna fed in a specific way and if you feed a 102 foot antenna in the center by any means the ANTENNA will behave exactly the same in ALL ways . I.E. patterns, height abvoe br/// above br/// above ground effects etc... The only subject of any difference is in the feed system. Charlie, W7XC -- From lwbyppp@epix.net Sat Mar 30 14:16:40 1996 From: zaax@aol.com (ZaaX) Newsgroups: rec.radio.amateur.antenna Subject: Re: Wideband Dipoles Date: 23 Mar 1996 10:13:45 -0500 Message-ID: <4j14f9$nb7@newsbf02.news.aol.com> References: <19960322.090337.87@southlin.demon.co.uk> Reply-To: zaax@aol.com (ZaaX) If you want to see an interesting broadband dipole check out the ARRl's "Antenna Compendium Vol.2" page 106-106. The design in here is very broadband. How does .500khz for 80m sound or .951khz for 40m sound? 73 Zack Schindler N8FNR From lwbyppp@epix.net Sat Mar 30 14:16:41 1996 From: w4avy@vulcan.com (W4AVY) Newsgroups: rec.radio.amateur.antenna Subject: Re: WTB: Mosley TW33 Beam Message-ID: <8BD4464.00140037E9.uuout@vulcan.com> Date: Sat, 23 Mar 96 18:44:00 -0600 Distribution: world Reply-To: w4avy@vulcan.com (W4AVY) References: <4hqevc$j91@homer.alpha.net> I want to buy a Mosley TW33 beam for 33, 17 and 12 meters. If you have one for sale please call 205 833-6278 or e-mail at W4AVY@vulcan.com. Thanks, Gary W4AVY --- * SLMR 2.1a * Unable to locate Coffee -- Operator Halted! From lwbyppp@epix.net Sat Mar 30 14:16:42 1996 From: w4avy@vulcan.com (W4AVY) Newsgroups: rec.radio.amateur.antenna Subject: Re: WTB: Mosley TW33 Beam Message-ID: <8BD4464.00140037EA.uuout@vulcan.com> Date: Sat, 23 Mar 96 18:44:00 -0600 Distribution: world Reply-To: w4avy@vulcan.com (W4AVY) References: <4hqevc$j91@homer.alpha.net> I want to buy a Mosley TW33 beam for 33, 17 and 12 meters. If you have one for sale please call 205 833-6278 or e-mail at W4AVY@vulcan.com. Thanks, Gary W4AVY --- * SLMR 2.1a * Unable to locate Coffee -- Operator Halted! From lwbyppp@epix.net Sat Mar 30 14:16:43 1996 From: w4avy@vulcan.com (W4AVY) Newsgroups: rec.radio.amateur.antenna Subject: Re: WTB: Mosley TW33 Beam Message-ID: <8BD4464.00140037EB.uuout@vulcan.com> Date: Sat, 23 Mar 96 18:44:00 -0600 Distribution: world Reply-To: w4avy@vulcan.com (W4AVY) References: <4hqevc$j91@homer.alpha.net> I want to buy a Mosley TW33 beam for 33, 17 and 12 meters. If you have one for sale please call 205 833-6278 or e-mail at W4AVY@vulcan.com. Thanks, Gary W4AVY --- * SLMR 2.1a * Unable to locate Coffee -- Operator Halted! From lwbyppp@epix.net Sat Mar 30 14:16:45 1996 From: w4avy@vulcan.com (W4AVY) Newsgroups: rec.radio.amateur.antenna Subject: Re: WTB: Mosley TW33 Beam Message-ID: <8BD4464.00140037EE.uuout@vulcan.com> Date: Sat, 23 Mar 96 18:44:00 -0600 Distribution: world Reply-To: w4avy@vulcan.com (W4AVY) References: <4hqevc$j91@homer.alpha.net> I want to buy a Mosley TW33 beam for 33, 17 and 12 meters. If you have one for sale please call 205 833-6278 or e-mail at W4AVY@vulcan.com. Thanks, Gary W4AVY --- * SLMR 2.1a * Unable to locate Coffee -- Operator Halted! From lwbyppp@epix.net Sat Mar 30 14:16:46 1996 From: w4avy@vulcan.com (W4AVY) Newsgroups: rec.radio.amateur.antenna Subject: Re: WTB: Mosley TW33 Beam Message-ID: <8BD4464.00140037EC.uuout@vulcan.com> Date: Sat, 23 Mar 96 18:44:00 -0600 Distribution: world Reply-To: w4avy@vulcan.com (W4AVY) References: <4hqevc$j91@homer.alpha.net> I want to buy a Mosley TW33 beam for 33, 17 and 12 meters. If you have one for sale please call 205 833-6278 or e-mail at W4AVY@vulcan.com. Thanks, Gary W4AVY --- * SLMR 2.1a * Unable to locate Coffee -- Operator Halted! From lwbyppp@epix.net Sat Mar 30 14:16:46 1996 From: w4avy@vulcan.com (W4AVY) Newsgroups: rec.radio.amateur.antenna Subject: Re: WTB: Mosley TW33 Beam Message-ID: <8BD4464.00140037ED.uuout@vulcan.com> Date: Sat, 23 Mar 96 18:44:00 -0600 Distribution: world Reply-To: w4avy@vulcan.com (W4AVY) References: <4hqevc$j91@homer.alpha.net> I want to buy a Mosley TW33 beam for 33, 17 and 12 meters. If you have one for sale please call 205 833-6278 or e-mail at W4AVY@vulcan.com. Thanks, Gary W4AVY --- * SLMR 2.1a * Unable to locate Coffee -- Operator Halted! From lwbyppp@epix.net Tue Apr 02 09:01:17 1996 From: dave@cybergate.com (Dave Morrow) Newsgroups: rec.radio.amateur.antenna Subject: 2m 1/4 Wave Glass Mount Advise Date: 24 Mar 1996 22:43:12 GMT Message-ID: <4j4j60$j05@opal.CyberGate.COM> Anyone have any comments on using a 1/4 wave glass mount antenna for 2 meters? any and all comments or suggestions would be greatly appreciated. Thanks, Dave From lwbyppp@epix.net Tue Apr 02 09:01:19 1996 From: Ron Newsgroups: alt.radio.scanner,alt.radio.pirate,aus.radio,rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc,rec.radio.scanner,rec.radio.shortwave,uk.radio.amateur Subject: Re: Shit, my FM-25 is Fucked! What to do?? Date: Wed, 27 Mar 1996 12:57:42 -0800 Message-ID: <3159ABC6.2B11@ix.netcom.com> References: <314C74DA.2BB3@shadow.net> <4iruql$66n@mars.spaceworks.com> <4itlar$3pd@tube.news.pipex.net> <31548C17.6F65B43E@sinister.com> <4j2adv$a6b@miwok.nbn.com> > -- > Gary... KJ6Q... I am the NRA | Annoy a Liberal - say NO to gun control! > ============================ | Annoy a Democrat - say BYE BYE CLINTON! > Those who choose to "beat |================================== > their swords into plowshares"| "It's *EASY* to be a liberal, it's > may end up *PLOWING* for | OTHER people's money you are giving > those who DON'T! | away! (or living off of!) Hey Gary, loved your taglines! Especially the one above about the plow- shares:) I realize this is a bit off-topic, considering the newsgroup, but do you listen to Rush? Cheers, Ron Cain From lwbyppp@epix.net Tue Apr 02 09:01:20 1996 From: Clint.Bradford@228.woodybbs.com (Clint Bradford) Date: 27 Mar 96 19:35:00 Newsgroups: rec.radio.amateur.antenna Subject: (removed) Message-ID: <3c9_9603280149@woodybbs.com> >>For legal reasons, any messages in this article that reveal >>I may have taken part in any illegal activity (either directly >>or indirectly) are hereby disclaimed. I hereby state that I >>have taken no part in any such activity. Worthless, meaningless "disclaimer," Nick. clint.bradford@atdbbs.com --- * TLX v4.00 * Useless laws weaken the necessary laws. * wcECHO 4.1 ~ AR-Net: ATTENTION to Details * Mira Loma, CA * 909-681-6221 -- |Fidonet: Clint Bradford 1:2619/228 |Internet: Clint.Bradford@228.woodybbs.com | | Standard disclaimer: The views of this user are strictly his own. From lwbyppp@epix.net Tue Apr 02 09:01:21 1996 From: Gary Watts Newsgroups: rec.radio.amateur.antenna Subject: Re: OK...now i'm mad at the hardline!!!!!! Date: Thu, 28 Mar 1996 13:27:08 -0600 Message-ID: References: <4jcgs2$3jlc@ns4-1.CC.Lehigh.EDU> David.. On Thu, 28 Mar 1996, Wes Stewart wrote: > >AAAAARG! > >and to think...i have a 800ft roll of this stuff laying in the backyard and i > >find out its useless!!! > > You can always use it for ground radials! > Or he could make a 160 meter LOOP antenna !! ;-) From lwbyppp@epix.net Tue Apr 02 09:01:22 1996 From: Cecil Moore Newsgroups: rec.radio.amateur.antenna Subject: Re: baluns in G5RV???. Date: 28 Mar 1996 15:49:29 GMT Distribution: world Message-ID: <4jece9$ld7@chnews.ch.intel.com> References: <360fkdg60.alamito@banana.speed.satlink.net> anibal@banana.speed.satlink.net (Anibal Aguirre) wrote: >Electromagnetics theory affirm that if exist an impedance change surface in >this surface appears a reflected wave.The solution at this are the baluns. Hi Anibal, baluns are usually designed for resistive loads. Unfortunately the load a balun sees in a G5RV is never resistive on some bands. I wouldn't run a G5RV without a balun and I wouldn't run a G5RV on 30M. A lot of hams think that the impedance at the coax/ladder-line junction in a G5RV goes from 50 ohms to 300 ohms. It almost never does. The impedance seen by the coax at the coax/ladder-line junction on my G5RV is around 12 ohms at resonance on 80M. A 1/4 balun would be better than a 1:1 or 4:1 in that case. 73, Cecil, KG7BK, OOTC (not speaking for my employer) From lwbyppp@epix.net Tue Apr 02 09:01:23 1996 From: wa4pgm@moonstar.com Newsgroups: rec.radio.amateur.antenna Subject: New Web Page Date: Thu, 28 Mar 96 20:37:22 EDT Message-ID: Check it out, under construction ! http:www.moonstar.com/~/wa4pgm/welcome What to add your link or anything else ??? Looking for ideas !! 73 Kyle From lwbyppp@epix.net Tue Apr 02 09:01:25 1996 From: "C. J. Hawley" Newsgroups: rec.radio.amateur.antenna Subject: Re: Failed HF Mobile Attempt Date: Fri, 29 Mar 1996 09:15:37 -0600 Message-ID: <315BFE99.18A0@uiuc.edu> References: <4jgol0$3gp@newsbf02.news.aol.com> To: LMcKelp LMcKelp wrote: > > Earlier this week I attempted to work HF mobile using a borrowed company > car on a company trip. My setup was as follows: > > Icom 735 > MFJ 941E tuner > Valor 40M mobile whip > "CB" style trunk mount > > My problem was that the SWR would not remain constant with the application > of power. With much difficulty, I could get the SWR down to acceptable > with the radio in low power mode, but when I raised the output power, the > SWR jumped to infinity each time. This occurred on 40, but when I > replaced the whip with a continuously loaded 4 ft long CB antenna, the > setup worked fine on 10, 11 (on a CB radio that I brought along also), 12, > and 15 and 17 meters. The thing that jumps to mind is corona at the top of the whip. You need to hav e a smooth, round ball on the tip. The corona problem is worse the lower you go in frequency and the higher the antenna Q, and with higher power. You are getting a lot of loss if you don't put the tuner at the antenna base and feed the vertical with a single ended output (all you need for a valor is a capacitor across the feedpoint and gnd, of about 500pf and adjust the whip to resonance. -- Charles Jack Hawley Jr. Amateur Radio KE9UW (A.K.A. 'Chuck' in Ham Radio) BMW K100RS, BMWMOA #224 (A.K.A. 'Jack' in Motorcycles) c-hawley@uiuc.edu Sr. Research Engineer Emeritus Univ of Ill, Urbana-Champaign From lwbyppp@epix.net Tue Apr 02 09:01:26 1996 From: w8jitom@aol.com (W8JI Tom) Newsgroups: rec.radio.amateur.antenna Subject: test Date: 29 Mar 1996 10:46:51 -0500 Message-ID: <4jh0lb$5ed@newsbf02.news.aol.com> Reply-To: w8jitom@aol.com (W8JI Tom) test From lwbyppp@epix.net Tue Apr 02 09:01:27 1996 From: chideste@xvnews.unconfigured.domain (Dale Chidester) Newsgroups: rec.radio.amateur.antenna Subject: Re: Ladder line length Date: 29 Mar 1996 13:02:27 GMT Message-ID: <4jgn13$nho@igate2.pt.cyanamid.com> References: <315a982f.6301082@news.borg.com> Reply-To: chideste@xvnews.unconfigured.domain In article 6301082@news.borg.com, ssouva@borg.com (Scott D. Souva) writes: >I'm about to hang a 160 meter dipole and will use 450 ohm ladder line >into an antenna tuner. My question is-- how long should the feedline >be? I've got 100 feet of the stuff and would like to cut it to an Scott, It should be long enough to get back to your tuner! That way you'll be able t o work all bands from the antenna. If you have to go through a wall with coax or something, a 9:1 or 4:1 balun (There seems to be some question about the ra tios) can be used. I wouldn't reccommend trying to get away without a tuner, in eit her case. I've only got enough room for an 80 meter dipole with about 75' of home made 450 ohm ladder line, a 9:1 balun and a Drake TN-2700 tuner. Works great on al l bands. 73 and good luck, Dale From lwbyppp@epix.net Tue Apr 02 09:01:28 1996 From: w7el@teleport.com (Roy Lewallen) Newsgroups: rec.radio.amateur.antenna Subject: Re: What is a current node Date: Fri, 29 Mar 96 17:40:48 GMT Message-ID: <4jh795$pr7@nadine.teleport.com> References: <4j9dd0$vsh@theory.tc.cornell.edu> In article , Cecil Moore wrote: >Kevin Schmidt writes: > >>Here the common use for "current node" seem to be for positions along a >>transmission line where the current magnitude is a maximum and the >>voltage is a minimum. > >Hi Kevin, I believe a "node" is defined as a point where the sign >of the slope changes. Current nodes are the points where the forward >and reflected currents add to a maximum. Voltage nodes are the points >where the forward and reflected voltages add to a maximum. The sum >of the currents is minimum at a voltage node and the sum of the >voltages is minimum at a current node. Current nodes are relatively >low resistance while voltage nodes are relatively high resistance. > >73, Cecil, KG7BK, OOTC This interesting definition explains a problem with communication we recently had. I don't recall encountering the term "current node" in any of my antenna or transmission line texts, and it isn't in the _IEEE Standard Dictionary of Electrical and Electronic Terms_, so I resorted to the definition of node I'm familar with. Webster: "a point at which a wave has an amplitude of zero". Because the current on a transmission line doesn't drop to zero, I incorrectly assumed that you meant "current minimum". Because your definition is almost opposite from Webster's, I'd suggest that you instead use "current maximum" to reduce confusion and enhance communication. Out of curiosity, what references do you have which use "current node" to mean point of maximum current? Roy Lewallen, W7EL Charter member, OFC From lwbyppp@epix.net Tue Apr 02 09:01:29 1996 From: w7el@teleport.com (Roy Lewallen) Newsgroups: rec.radio.amateur.antenna Subject: Re: Improving F/B ratio with lossy dielectric? Date: Fri, 29 Mar 96 17:46:03 GMT Message-ID: <4jh7j0$pr7@nadine.teleport.com> References: <4jf005$1sr@lll-winken.llnl.gov> In article <4jf005$1sr@lll-winken.llnl.gov>, Dave Benzel wrote: >I am wondering if anyone has experience with improving the front/back >ratio of an antenna by placing a lossy dielectric (RF poor plastic) >rearward? If so, are there any recomendations as to the type of >dielectric and thickness required? > >Specifically, I have a patch antenna for 900 MHz with a specified F/B >ratio of 18 dB, but I need at least 22 dB. I would like to mount the >patch (a Cushcraft Data Patch antanna) on a roughtly 16x16 inch sheet of >plastic. > >Thanks - Dave Hopefully, you'll get some answers from people who have tried this and know what to expect. If you don't, you might try ferrite-loaded absorbing materials. Several varieties are (or were) available in the form of paint and ferrite-loaded silicone sheet from Emerson & Cuming (617-828-3300). Roy Lewallen, W7EL From lwbyppp@epix.net Tue Apr 02 09:01:30 1996 From: David Nulton Newsgroups: rec.radio.amateur.antenna Subject: Need Guidlines for F.S. Tower Bases Date: 29 Mar 1996 19:11:34 GMT Message-ID: <4jhcl7$6ge@alterdial.UU.NET> A friend of mine has a free standing tower and needs some info on how to make the base for it. We have two problems here. 1. How big should the base be. (i.e. should the mass of the concrete equal or be more than the mass of the tower? Are we trying to shift the center of gravity to below the soil?) 2. In central Texas the soil has alot of limestone in it. It is very difficult to even dig a hole for a rose bush, let alone a tower base. We have talked to some drilling companies, but prices are up in the thousands of dollars. Explosives are out of the question. Any advice on how to dig the hole? Can a compromise be made by digging a shallower, but wider pit? Any advice is appreciated. My friend is going to seek help from the County Engineer. However at this point we no not what were doing. Thanks in advance 73s de KI5XW From lwbyppp@epix.net Tue Apr 02 09:01:31 1996 From: Cecil Moore Newsgroups: rec.radio.amateur.antenna Subject: Re: Ladder line length Date: 29 Mar 1996 22:47:48 GMT Message-ID: <4jhpak$sac@itnews.sc.intel.com> References: <315a982f.6301082@news.borg.com> <315C2A63.53CD@bu.edu> "Carmine M. Iannace" wrote: >If your attaching the line to the balanced inputs of a >tuner the lenght of line is, in a practical sense, not important. Hi Carmine, If the output of the tuner is balanced by a balun, the length of the line matters a lot. Assume a 50 ohm antenna fed by a quarter wavelength of 450 ohm ladder-line. Don't think the balun is going to like feeding 4000 ohms. 73, Cecil, KG7BK, OOTC (not speaking for my employer) From lwbyppp@epix.net Tue Apr 02 09:01:32 1996 From: Cecil Moore Newsgroups: rec.radio.amateur.antenna Subject: Re: What's a G5RV Date: Sat, 30 Mar 96 00:29:57 -0500 Message-ID: References: <4jg1ae$gom@news.asu.edu> CHARLES J. MICHAELS writes: > Wouldn't this thread be simpler if it is recognized that >a *G5RV* is a 102 foot antenna fed in a specific way and if you >feed a 102 foot antenna in the center by any means the ANTENNA >will behave exactly the same in ALL ways . I.E. patterns, height Hi Charlie, you're right in that any 102 ft dipole will radiate the same percentage of power reaching it. It's the total power that we are discussing. If there's neglible loss in the feed system, the antenna will radiate more power than if there's not neglible loss in the feed system. I haven't changed my antenna but I am radiating at least double the RF power on 75m after I gave the 4:1 a load of 300 ohms resistive instead of the 1000+j2000 ohm load that I was previously giving it. 73, Cecil, KG7BK, OOTC From lwbyppp@epix.net Tue Apr 02 09:01:33 1996 From: dbwillia@uci.edu (Brian Williams) Newsgroups: rec.radio.amateur.antenna Subject: Re: Feeding dual-band antennas w/multiple rigs? Date: 30 Mar 1996 01:02:43 GMT Message-ID: <4ji17j$o5a@news.service.uci.edu> References: <4jbl70$1v9@elmgate.raster.Kodak.Com> In article <4jbl70$1v9@elmgate.raster.Kodak.Com>, rkm@scanproj.raster.kodak.com asks... > When feeding a dual-band antenna with a single feed point, >will a duplexer permit you to feed it with 2 rigs ( 2M and 70cm, >for example ) simultaneously, in both transmit and receive? >And, if so, where I can I get more info about commerical offerings >or plans to build one? >Thanks, > - Rich Any of the Comet, Diamond, etc. diplexers are able to be used bi-directionally (Two antennas with one transmitter or one antenna with two transmitters. Brian N6ZAU From lwbyppp@epix.net Tue Apr 02 09:01:34 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: Ladder line length Date: Sat, 30 Mar 96 06:01:03 GMT Message-ID: <4jij3k$l29@crash.microserve.net> References: <315a982f.6301082@news.borg.com> <315C2A63.53CD@bu.edu> "Carmine M. Iannace" wrote: >If your attaching the line to the balanced inputs of a tuner the >lenght of line is, in a practical sense, not important. Just run the >line all the way to the tuner and simply cut off any excess. If you're using the typical modern tuner with a built-in balun, line length is *very* important. If the impedance seen by the balun isn't correct, the balun ceases to function and causes A) feedline imbalance and B) power consumption in the balun. See Tom's post for more info. 73, Jack WB3U From lwbyppp@epix.net Tue Apr 02 09:01:35 1996 From: jackl@pinetree.microserve.com (WB3U) Newsgroups: rec.radio.amateur.antenna Subject: Re: Failed HF Mobile Attempt Date: Sat, 30 Mar 96 06:08:15 GMT Message-ID: <4jijh3$l29@crash.microserve.net> References: <4jgol0$3gp@newsbf02.news.aol.com> lmckelp@aol.com (LMcKelp) wrote: >By the way, I peaked the 40 meter setup on receive to get close >and save my finals first, and after adding power and losing the >match, the receive signal was lower also. To me, that usually indicates that an arc has occurred and that the arc has left behind a conductive (carbon) path. Probably, each time you reloaded at low power then switched to high power, the arc was depositing another (or more significant) path. I wonder if the setscrews were making good contact to the sheetmetal? 73, Jack WB3U From lwbyppp@epix.net Tue Apr 02 09:01:36 1996 From: w8jitom@aol.com (W8JI Tom) Newsgroups: rec.radio.amateur.antenna Subject: Re: Failed HF Mobile Attempt Date: 30 Mar 1996 07:59:26 -0500 Message-ID: <4jjb7e$bg@newsbf02.news.aol.com> References: <4jijh3$l29@crash.microserve.net> In article <4jijh3$l29@crash.microserve.net>, jackl@pinetree.microserve.com (WB3U) writes: > >To me, that usually indicates that an arc has occurred and that the >arc has left behind a conductive (carbon) path. Probably, each time >you reloaded at low power then switched to high power, the arc was >depositing another (or more significant) path. I wonder if the >setscrews were making good contact to the sheetmetal? > >73, >Jack WB3U I agree with Jack, but I'd like to add it could be arcing from the trunk to the car chassis either at the hinges, latch, or both The entire CAR only looks like a few hundred pF of capacitance to ground on 80 meters, image what the trunk lid "looks like". It's not a very good ground at all except perhaps on ten meters and up! Any arc between the mount and the deck lid, or the deck lid and the car body, will do exactly what you describe. And putting a tuner at the rig will only extend the range of frequency slightly. A mobile antenna changes impedance much more rapidly with frequency than a big antenna. The only "good place" for the tuner with a physically VERY short (in relation to the frequency) antenna is right back at the antenna. 73 Tom From lwbyppp@epix.net Tue Apr 02 09:01:38 1996 From: w8jitom@aol.com (W8JI Tom) Newsgroups: rec.radio.amateur.antenna Subject: Re: Ignorant question: What's a G5RV??? Date: 30 Mar 1996 07:59:42 -0500 Message-ID: <4jjb7u$bl@newsbf02.news.aol.com> References: <4jikjt$14k4@chnews.ch.intel.com> In article <4jikjt$14k4@chnews.ch.intel.com>, cmoore@vegas.ch.intel.com (Cecil A. Moore~) writes: >>Whatever scheme drives the currents, we face the physical fact that the >>shorter the elements are, the more of the last high current node will end >>up wasted, cancelling itself inside the feeder, >Here's what happens: If the antenna were 50 ohms resistive, the >current from 100 watts would be 1.414 amps at the antenna. Now >let's shorten the antenna to move the current maximum back down >the transmission line and let's say it's still 1.414 amps maximum >in the transmission line. The antenna impedance will have gone >up - let's make it easy and say to 500 ohms for sake of illustration >only. Shortening the antenna makes the impedance DROP, not go up! Current IN THE ANTENNA GOES UP, not down. Only current causes the type of radiation we want. Let's say we have a short antenna with a current of one amp throughout the entire length. With the same amount of applied power, a triangular distribution (same antenna) would now produce two amperes at the current loop (and zero at the Node) and the SAME radiated power. A fixed amount of power applied to a thin, short, linear diameter whip on 160 has MORE current at the feedpoint than the same whip when top loaded(~ twice as much). At the top current is zero in the base loaded antenna, at the middle the currents are equal. What really happens in the G5RV on 80 (or any other antenna that is shortened while maintaining the same basic current distribution shape) is the current in the antenna *increases* until the total power radiated is the same. As the length of the radiating area is reduced with the same power applied (it MUST be radiated if applied), the over all current increases. Current from the G5RV does not "move into the feeder" and become canceled. Current in the element goes up! Think about it this way, do you worry about the "current that could have been radiating" in your RG-8 fed dipole because current "moved into the feeder? If feeder current was a real worry, we'd all be using folded dipoles to keep current out of the feeder. The only current or radiated power "lost" in the transmission line comes from normal line attenuation, not because current is "there". 73 Tom From lwbyppp@epix.net Tue Apr 02 09:01:39 1996 Newsgroups: rec.radio.amateur.antenna From: john@wd1v.mv.com (John Seney) Subject: Mac Ham Users Group Message-ID: Date: Sat, 30 Mar 1996 09:07:41 GMT "Macnet Roster" (ver. 739) has just been updated and is now a stand-alone application! The version number = the number of hams using Macs. "Macnet Roster" lists: o CALL SIGN @ HOME PBBS o FULL NAME o ADDRESS o CITY, STATE, ZIP o INTERNET ADDRESS o MACS USED o RADIOS USED o SOFTWARE USED o PASSIONS o COMMENTS of every known amateur radio operator in the world that uses a Mac computer. You can use "Macnet Roster" to find other Mac users that you can then communicate with directly. Compare notes on software, applications, ideas, hints and kinks, and make new ham friends that use the same computer you do. (You already know how cool you are - imagine accessing "the rest of us"!) If you'd like the latest "Macnet Roster": Send me a formatted disk in a self addressed and stamped disk mailer that is in a large envelope clearly marked "ROSTER". Or connect to my home page via the WWW http://www.mv.com/ipusers/wd1v Put YOUR INFO (via EMAIL or disk using TEACH TEXT) if you'd like to be include d in the "Macnet Roster" or send an update to your stats to me via pkt or email anytime. John D. Seney |_|_|_|_| e-mail: john@wd1v.mv.com 144 Pepperidge Dr |_| |_| www http://www.mv.com/ipusers/wd1v Manchester, NH 03103-6150 |_|_ _|_| wireless: wd1v@wb1dsw.nh.usa.noam Voice Mail: 603-533-3472 | | | | | skytel page: 5956779@skymail.com From lwbyppp@epix.net Tue Apr 02 09:01:40 1996 From: Cecil Moore Newsgroups: rec.radio.amateur.antenna Subject: Re: Ignorant question: What's a G5RV??? Date: Sat, 30 Mar 96 12:03:53 -0500 Message-ID: References: <4jikjt$14k4@chnews.ch.intel.com> <4jjb7u$bl@newsbf02.news.aol.com> W8JI Tom writes: >Shortening the antenna makes the impedance DROP, not go up! Current IN THE >ANTENNA GOES UP, not down. Hi Tom, Sorry I forgot to indicate that my illustration was for the G5RV on 20m, the band for which it was designed. I actually shortened my G5RV from 102 ft. to 88 ft. and the antenna impedance went up, not down. EZNEC says 117-j43 for a 102 ft. dipole on 20m and 165-j795 for an 88 ft. dipole on 20m. The current maximum point moved away from the antenna when it was shortened and the current into the antenna dropped but it still radiated the same amount of power but into a more desirable radiation pattern. 73, Cecil, KG7BK, OOTC From lwbyppp@epix.net Tue Apr 02 09:01:41 1996 From: walchwl@wkuvx1.wku.edu Newsgroups: rec.radio.amateur.antenna Subject: Date: 30 Mar 96 15:16:22 CDT Message-ID: <1996Mar30.151622@wkuvx1.wku.edu> I would be interested in full or part of your mag collection send response to WALCHWL.WKUVX1.WKU.EDU From lwbyppp@epix.net Tue Apr 02 09:01:42 1996 From: lmckelp@aol.com (LMcKelp) Newsgroups: rec.radio.amateur.antenna Subject: Re: Failed HF Mobile Attempt Date: 30 Mar 1996 15:32:48 -0500 Message-ID: <4jk5pg$8a0@newsbf02.news.aol.com> References: <4jjb7e$bg@newsbf02.news.aol.com> Well, now there are more clues to this mystery. I brought the rig (and tuner( back into the house, where I had been using it to good effect prior to my trip. By the way, I live in a duplex apartment with total antenna restrictions, so I've been using a random length wire tuned by the tuner. Now, I'm having the same problem on 40 meters in the house. Also, I seem to be getting enough RF in the "shack" to cause my radio to shut off when loading up on 20 meters, EVEN WHEN PROPERLY MATCHED! The power supply stays on, but some internal circuit in the radio causes the power to go off, and I have to shut off the power supply with the radio power supply on to get the radio to come back on. I've experienced this before with random wires on trips to visit family, always on end fed, random length wires, so I know what causes it. I don't know what to do now, as the wire worked fine on all bands before the trip. I have an idea of trying one of the triple magnet mounts for the trunk. Any of you guys have any experience, either personal or anecdotal, of how they work on the lower HF bands? I'd like to know before I plunk down $45 or so. Thanks for the help and advise so far... Levi N5ZFM From lwbyppp@epix.net Tue Apr 02 09:01:44 1996 From: w8jitom@aol.com (W8JI Tom) Newsgroups: rec.radio.amateur.antenna Subject: Re: Failed HF Mobile Attempt Date: 30 Mar 1996 19:14:23 -0500 Message-ID: <4jkiov$d67@newsbf02.news.aol.com> References: <4jk5pg$8a0@newsbf02.news.aol.com> In article <4jk5pg$8a0@newsbf02.news.aol.com>, lmckelp@aol.com (LMcKelp) writes: >Now, I'm having the same problem on 40 meters in the house. Also, I seem >to be getting enough RF in the "shack" to cause my radio to shut off when >loading up on 20 meters, EVEN WHEN PROPERLY MATCHED! The power supply >stays on, but some internal circuit in the radio causes the power to go >off, and I have to shut off the power supply with the radio power supply >on to get the radio to come back on. I've experienced this before with >random wires on trips to visit family, always on end fed, random length >wires, so I know what causes it. You need a good RF ground. SWR has NOTHING to do with RF floating around the shack. There are many ways to get an RF ground, but what they all involve is having something that looks like a large electrical mass at the rig. That can be as simple as a few counterpoise wires, as complex as sixty or a hundred radials, or as innovative as lining the floor of your shack under the carpet with aluminum foil that you ground to the radio and power supply chassis ground post. >I don't know what to do now, as the wire worked fine on all bands before >the trip. I have an idea of trying one of the triple magnet mounts for >the trunk. Any of you guys have any experience, either personal or >anecdotal, of how they work on the lower HF bands? I'd like to know >before I plunk down $45 or so. Hmm. That's strange. A triple mag mount may give you the same trouble you had with the lip mount. I've seen mag mounts burn holes in paint at HF. 73 Tom From lwbyppp@epix.net Tue Apr 02 09:01:46 1996 From: Cecil Moore Newsgroups: rec.radio.amateur.antenna Subject: Re: Ignorant question: What's a G5RV??? Date: 30 Mar 1996 19:29:59 GMT Distribution: world Message-ID: <4jk23n$14qa@chnews.ch.intel.com> References: <314DC5B9.588F@vertex.ucls.uchicago.edu> <19960322.094220.22@southlin.demon.co.uk> <19960324.182928.72@southlin.demon.co.uk> <4jikjt$14k4@chnews.ch.intel.com> cmoore@vegas.ch.intel.com (Cecil A. Moore~) wrote: Before I get any more email on this posting: This example was based on what happened to my TWENTY METER antenna impedance when I shortened it from 102 ft. to 88 ft. The antenna impedance went from a resonant 127 ohms on 14.33 MHz to 158-j752. I exagerated the following to make a point. The point is: It doesn't matter if the antenna impedance is high or low if the delivery system is lossless. >Let's >assume that the antenna reactance is conjugately matched and not >causing any losses. Also assume near-lossless open-wire feeder. >Here's what happens: If the antenna were 50 ohms resistive, the >current from 100 watts would be 1.414 amps at the antenna. Now >let's shorten the antenna to move the current maximum back down >the transmission line and let's say it's still 1.414 amps maximum >in the transmission line. The antenna impedance will have gone >up - let's make it easy and say to 500 ohms for sake of illustration >only. The current at the antenna will be only 0.45 amp now but >guess what? (1.414)^2*50 = (0.45)^2*500 Even though the current >has dropped by 68% at the antenna, the power delivered to >the antenna is still the same old 100 watts. It's not really >that simple but I think this example illustrates why high current >with a low impedance antenna can be identical, power-wise, to >low current with a high impedance antenna. If the losses are >made to be neglible, then the "last high current node" will >not "end up wasted". The antenna impedance doesn't matter >(within reason) if it is matched with a neglible loss >delivery system. As a matter of fact, in the above illustration, >unless one knows better, one can't tell that the 500 ohm antenna >is not at the current maximum and the results will be almost the >same for both antennas assuming similar radiation patterns. From lwbyppp@epix.net Tue Apr 02 09:01:47 1996 From: drhodes@islandnet.com (Douglas Rhodes) Newsgroups: rec.radio.amateur.antenna Subject: Field Day Special Date: 31 Mar 1996 01:41:15 GMT Message-ID: <4jknrr$rrh@sanjuan.islandnet.com> QST magazine had an article by W7EL about eight or ten years ago with description and dimensions for a modified ZL-special for twenty meters, which Roy Llewellyn called the Field Day Special. I've been using it happily for two years, but would like to try something different on twenty and re-cut the FD-special for 15 meters. Has anybody (including W7EL) re-modelled it for other bands? Doug Rhodes, VE7DFZ Victoria, British Columbia From lwbyppp@epix.net Tue Apr 02 09:01:48 1996 From: l.mclaughlin@slipid.async.csuohio.edu (Bostonian) Newsgroups: rec.radio.amateur.antenna Subject: WTD: RCA WT-100A OR HICKOK 700 TUBE TESTER Date: 31 Mar 1996 01:44:32 GMT Message-ID: <4jko20$5i7@csu-b.csuohio.edu> RCA WT-100A and/or Hickok 700 tube tester wanted. Seeking unit in good running condition, needing some repairs or for parts (if I later come across a working unit). Willing to swap for something or please state a fair price for the respective unit. I would prefer swapping something as cash is tight, but I would have to find out what you are looking for -- I may have it. Please indicate if you have manuals, schematics, charts and/or plug-in tube sockets for the respective tube tester. Kindly, email with details. Thank you.  From lwbyppp@epix.net Tue Apr 02 09:01:49 1996 From: Charles Bolland Newsgroups: rec.radio.swap,rec.radio.amateur.antenna,rec.radio.amateur.digital.misc,rec.radio.amateur.equipment,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.amateur.policy,rec.radio.amateur.space,rec.radio.noncomm,rec.radio.scanner,rec.radio.shortwave,rec.radio.swap Subject: Shortwave etc database program.... Date: Sun, 31 Mar 1996 10:51:57 -0800 Message-ID: <315ED44D.1E94@flinet.com> Sir, A stand alone IBM compatible Broadcasting Radio Station Database program for Longwave, Mediumwave, or Shortwave. 4000 records... Completely read/write and updateable... If you'd like a copy, send your EMail address and Postal Address which will be used to pass you more detailed information on the full featured program.... The above program will be sent via EMAIL... All information will be kept confidential.... Chuck KA4PRF From lwbyppp@epix.net Tue Apr 02 09:01:50 1996 From: Newsgroups: alt.radio.scanner,alt.radio.pirate,aus.radio,rec.radio.amateur.antenna,rec.radio.amateur.equipment,rec.radio.amateur.misc,rec.radio.scanner,rec.radio.shortwave,uk.radio.amateur Subject: Naughty Rude Words Date: 31 Mar 1996 11:05:54 GMT Message-ID: <4jloui$lmr@juliana.sprynet.com> This thread having to do with the messed up FM-25 has certainly gotten the mil eage. We're all behaving like a bunch of politicians: making a lot of noise about s omething that is not in the least bit important. An emotional issue and therefore not conducive to rational discussion. We're talking about words here, not some threat to personal or national securi ty, or to the health and general welfare of mankind. Just words. Every time I read another shrill and strident post on this subject I think about what my son (10 at the time) said when Pee Wee Herman was busted , "Isn't that what people do when they watch porno flicks?" Oh, that wonderful purity of a child's morality. Come on folks, let's drop this thing for good. It's a waste of resources and time and it's getting ridiculous what with the patriots, the freedom fight ers and the moralists getting all frothed up. What has finally done it for me is a messag e I read today that alludes to posts acceptable for "family channels" and "mixed company" yet has a signature block that contains the suggestive double entendre "Hams do it bounc ing off the "F" layer." What a hypocritical, self-righteous prig! From lwbyppp@epix.net Tue Apr 02 09:01:51 1996 From: cheply@coastnet.com (Rob Cheply) Newsgroups: rec.radio.amateur.antenna Subject: yagi antenna help!! Date: Sun, 31 Mar 1996 11:57:56 GMT Message-ID: <4jlrmi$cj3@nntp.pinc.com> HI i was wondering if anyone knows if there is somewhere I can download a diagram of a Yagi antenna with all the lengths of the peices for the 143 - 144 Mhz range. If so please tell me Thanx Cory Cheply cheply@coastnet.com From lwbyppp@epix.net Tue Apr 02 09:01:52 1996 From: "H. Mark Nadel" Newsgroups: rec.radio.amateur.antenna Subject: Hams helping Hams ! Date: Sun, 31 Mar 1996 12:28:17 -0800 Message-ID: <315EEAE1.6D99@i-2000.com> When you have an oportunity please check out the home page of the Radio Amateurs Defense & Information Organization, ( R.A.D.I.O. ) We are in need of your support. The address is http://www.islandlink.com/radio/radio.htm Thank you -- <<<>>> From lwbyppp@epix.net Tue Apr 02 09:01:54 1996 From: MMcanally@gnn.com (Mark McAnally) Newsgroups: rec.radio.amateur.antenna Subject: * * * AFFORDABLE QSL CARDS * * * Date: Sun, 31 Mar 1996 12:58:59 Message-ID: <4jmkf1$f95@news-e2b.gnn.com> After some checking, I found out that QSL cards cost anywhere from $70.00 to $450.00 per 1000 cards to be printed up. I also found out that you are pretty limited to the color of card, artwork and color of ink to choose from. I have been printing cards for my ham friends for some time now and I have been encouraged by my friends to branch out and advertise a little. I can print 1000 cards with black ink for only $50.00. Why should you order your cards from me? Because $50.00 is it! No shipping charges, no setup charges, no hidden costs. PLUS...you have your choice of 13 card colors, unlimited artwork, and you can have up to FIVE different layouts per order. Want color ink? For example, do you want a red, white and blue US flag on your cards? That would only be $65.00 per 1000, with 13 card colors to choose from, up to FIVE different layouts, and unlimited artwork in black or colors. Your card color choices are white, blue, yellow, pink, green, ivory, peach, gray, and the following eyepopping flourescents: yellow, pink, green, blue, and red. Artwork is too numerous to list all designs here, but just some examples would be an ARRL logo, ARES logo, SKYWARN logo, flags of all 50 states, maps of all 50 states, antennas and radios, flags and maps of US territories and foreign countries and 1000's more... Custom artwork available at NO ADDITIONAL CHARGE!!! Just tell me what you want!!! Reply via private email for a FREE sample snail mailed to you today! To place an order call Mark at (904) 626-2450 or FAX (904)626-7686 or you can mail check or money order to: McAnally and Associates 6223 Hwy 90 Suite 301 Milton, FL 32570-1708 From lwbyppp@epix.net Tue Apr 02 09:01:54 1996 From: red5or7@aol.com (Red5or7) Newsgroups: rec.radio.amateur.antenna Subject: Re: OK...now i'm mad at the hardline!!!!!! Date: 31 Mar 1996 15:48:15 -0500 Message-ID: <4jmr2f$3ij@newsbf02.news.aol.com> References: <4jmo70$22ti@ns2-1.CC.Lehigh.EDU> Reply-To: red5or7@aol.com (Red5or7) Hmmm. Somehow I missed this one. What is the problem...why is the hardline causing you all this grief? Perhaps this (old & broken down) ex-radio engineer can help! Re-post & I'll see what answers I can come up with. From lwbyppp@epix.net Tue Apr 02 09:01:55 1996 From: David Nulton Newsgroups: rec.radio.amateur.antenna Subject: Re: Propagation Query Date: 31 Mar 1996 18:30:42 GMT Message-ID: <4jmj0i$9po@alterdial.UU.NET> References: <4je44e$182k@ns1-1.CC.Lehigh.EDU> 10 meters is rarely open during the day, but some contacts do exists. 15 meters is almost as bad - some DX. 17 meters is better bud signals are fading. 20 meters is good during the day, but still suffers from fading. Right now 160, 80 and 40 are perferred for evenings and nights. The noise level on these bands is better than its been, with the exception of atmospheric noise from thunderstorms. We are definately at the solar minimum. Solar activity should start to increase in 97 and be much better by 99. The bands are still worth using, and you can work good DX. However, you will have to look harder than you did 5 years ago. 73s de KI5XW From lwbyppp@epix.net Tue Apr 02 09:01:56 1996 From: David Nulton Newsgroups: rec.radio.amateur.antenna Subject: Re: no tune antenna Date: 31 Mar 1996 18:36:50 GMT Message-ID: <4jmjc3$9po@alterdial.UU.NET> References: <4j8sf1$ioo@nntp.netside.com> <4jem0t$hlm@news1.inlink.com> I saw an ad for an all-band no-tune antenna in the last QST. It was only 30" long WOW! Then again it was the april issue. Seriously, what you ask is difficult. Have you looked at trap dipoles? If you have a variable inductor, you may be able to set a cheap verticle made out of chain link fence top rail, or conduit. Use the inductor to tune the lower bands. Even then I think you'll find 80-10m coverage hard to achieve. With conditions the way they are, if you could use 80, 40 and possibley 20 you'd be doing great. Perhaps you'll get the tuner fixed, or better antenna by the time the solar conditions improve. 73s de KI5XW From lwbyppp@epix.net Tue Apr 02 09:01:57 1996 From: rvr@pacifier.com (Ron Ries) Newsgroups: rec.radio.amateur.antenna Subject: SSB DX antennas for 2M Date: 31 Mar 1996 20:41:47 GMT Message-ID: <4jmqmc$891@news.pacifier.com> I am considering a 2m horizontally polarized gain antenna for 2M DX. I live in an antenna restricted area but could get away with 12 foot boom. Have considered the KLM, M2, and Lightning Bolt 10 element quad. Any comments on performance or other factors that would influence a selection? Any other suggestions of other mfrs? 73 Ron KG7LR -- Arizona Dreamin' From lwbyppp@epix.net Tue Apr 02 09:01:58 1996 From: ua666@localnet.com Newsgroups: rec.radio.amateur.antenna Subject: MFJ Antenna Date: Sun, 31 Mar 96 21:20:21 EDT Message-ID: Anybody have a schematic of the MFJ "Tower In A Box" This consists more or less of a 54" whip mounted on top of a phenolic box with a tunner built into it. ? From lwbyppp@epix.net Tue Apr 02 09:01:59 1996 From: orrin@stinger.redshift.com (Orrin Winton) Newsgroups: rec.radio.amateur.antenna Subject: rhombic design update Date: 31 Mar 1996 23:24:45 GMT Message-ID: <4jn47t$11u@wing.redshift.com> Was recently informed that one of the programs in my rhombic design package had a bug; this is now fixed. The bug was in a no-graphics program called rhom.exe originally written in gwbasic; apparently the QuickBasic 4.5 compiler didn't like some of the code and produced an unusable program. This is now fixed, and the source code in basic is included. The C-language version never had this particular bug (rhom112.exe). The whole little collection can be gotten from my ftp site ; if you use Netscape it's ftp://redshift.com/orrin/112rhom.exe A Windows version is ftp://redshift.com/orrin/204rhom.exe On a different note, i am making Web space available for articles written by people 'out there' who feel they have been treated poorly by packet-radio sysops -- this refers mainly to the more traditional "all radio" network. Details can be found on my Web page: http://www.redshift.com/~orrin and click on the link for "The Sysop Syndrome." orrin@redshift.com