Date: Tue, 28 Jun 94 04:30:14 PDT From: Ham-Ant Mailing List and Newsgroup Errors-To: Ham-Ant-Errors@UCSD.Edu Reply-To: Ham-Ant@UCSD.Edu Precedence: Bulk Subject: Ham-Ant Digest V94 #202 To: Ham-Ant Ham-Ant Digest Tue, 28 Jun 94 Volume 94 : Issue 202 Today's Topics: Antenna books, JASIK, ARRL antenna tower erection Followup : Static electricity on balloon antennas GAP Eagle Antenna -- Anyone Have Experiences? GPS group purchase shutdown (3 msgs) HF Mobile Antennas J-Poles and Baluns (2 msgs) need heathkit data Quadfiliar helix for GPS Switching Relays for Ladder Line? Thick Ethernet cable Thick Ethernet cable in place of RG cables ??? Send Replies or notes for publication to: Send subscription requests to: Problems you can't solve otherwise to brian@ucsd.edu. Archives of past issues of the Ham-Ant Digest are available (by FTP only) from UCSD.Edu in directory "mailarchives/ham-ant". We trust that readers are intelligent enough to realize that all text herein consists of personal comments and does not represent the official policies or positions of any party. Your mileage may vary. So there. ---------------------------------------------------------------------- Date: Tue, 28 Jun 94 00:48:00 +0200 From: ihnp4.ucsd.edu!usc!howland.reston.ans.net!EU.net!news.eunet.fi!gate.compart.fi!compart!heikki.partanen@network.ucsd.edu Subject: Antenna books, JASIK, ARRL To: ham-ant@ucsd.edu I am interested to know if there is any possibility to find an exemplar of Antenna Engineering Handbook from 1961 or later. The Editor of the first edition is HENRY JASIK. The book is published in New York, Toronto and London by McGRAW-HILL BOOK COMPANY, INC. I am interested in particularly of the chapters: 4, 5, 6, 7, 17, 18, 21, 22, 24, 30, 31, 33, 34 and 35. Please, lett me know. I shall wait any positive advise. Yours Heikki P.S. If somebody wants to contribute in finding a lose sample of ARRL's Antenna Handbook, I also shall wait any answer to my E-mail-address. Heikki P.P.S. Is there better antenna handbook than ARRL antenna Handbook to practical antenna building? Please send Your answers to my e-mail-address: heikki.partanen@compart.fi or henripar@freenet.hut.fi Thanks and have a good summer. ------------------------------ Date: Mon, 27 Jun 1994 21:03:02 From: ihnp4.ucsd.edu!dog.ee.lbl.gov!agate!howland.reston.ans.net!europa.eng.gtefsd.com!sundog.tiac.net!news.sprintlink.net!nwnexus!olympus.net!olympus.net!vaughnwt@network.ucsd.edu Subject: antenna tower erection To: ham-ant@ucsd.edu >I just was listening on the 40 meter wavelength to a conversation >about a friend of someone's who was affiliated in some manner >(one-time section manager or something) to the ARRL. He was up on >his tower working on something and somehow his safety belt got >hung up. Don't ask me how, I guess its possible with what might >be going on at the top of a tower....but the gentleman apparently >couldn't get free of his situation and released his safety belt >whereupon he fell freefalling to the top of his house and then >bounced off the roof, onto the pavement on his driveway. The poor >fellow is in a wheelchair and not expected to be able to walk >around anymore. His friend on the radio said that it's too bad >because the guy was very active. >Just more to think about..even with a safety belt and years of >experience climbing towers and being part of tower raising parties, >all it takes is one fall. >Definitely try to get help from some local guys before doing >something like raising a tower! >73's Tony Also a very good argument for TWO safety belts. One of the two should be connected at all times. Bill KB7MRF William Vaughn vaughnwt@olympus.net "Just plain Bill." ------------------------------ Date: Mon, 27 Jun 1994 16:48:12 GMT From: ihnp4.ucsd.edu!swrinde!gatech!newsfeed.pitt.edu!gvls1!rossi@network.ucsd.edu Subject: Followup : Static electricity on balloon antennas To: ham-ant@ucsd.edu A couple weeks ago there was an article posted here about using balloon antennas for Field Day and how there was considerable static electricity buildup on long wires. I figured that might be true for these 300-500 foot wires that were being discussed but figured that it would be unlikely on short wires. Well this past weekend (Field Day) I discovered that it can happen on shorter wires too. I was using a 67 ft half-wave wire vertical suspended from a kite. At one point while I was setting up, I had the kite flying overhead with the antenna wire just hanging from the kite string and the bottom end just hovering a few feet above the FD site. There was a nice 15-20 MPH breeze. While I was getting the kite in position, a few times I reached for the wire to move it into position and each time I would get a very mild shock, similar to what you get when you walk across the carpet in the winter and touch a light switch. The first time I just thought it was odd but when it happened a second time it suddenly clicked as to what was going on. Once I got things set up, the wire was DC grounded through my tuner so there was no further static problems. Very interesting... ---- Pete Rossi - WA3NNA rossi@vfl.paramax.com Unisys Corporation - Government Systems Group Valley Forge Engineering Center - Paoli, Pennsylvania ------------------------------ Date: 27 Jun 1994 20:27:44 GMT From: ihnp4.ucsd.edu!usc!elroy.jpl.nasa.gov!ncar!elmore@network.ucsd.edu Subject: GAP Eagle Antenna -- Anyone Have Experiences? To: ham-ant@ucsd.edu For the Curious, the GAP is some flavor of center-fed linear-loaded, stub-tuned vertical dipole. Over Father's Day, I took a trip to Tulsa to help my Dad put up a new antenna: the GAP Eagle. It covers 40, 20, 17, 15, 12 and 10 m. We felt that some modifications to it's basic sonstruction were in order: GAP liberally uses stainless steel #10 sheet metal screws in the antenna construction. Om Oklahome, the wind is relentless and we felt this was suboptimal. So, we used 1/4 x 20 stainless cap screws that extend through the antenna, with nylok nuts. We also doubled up on the wall thickness in the lower half of the antenna by inserting the next-size smaller aluminum tubing. The antenna tunes just as advertised and is nicely broad-banded. To our disappointment though, we've found the GAP to be about 10 dB down from a 1/4 wave, ground-mounted vertical using no radials. This seriously puzzles me; there's no reason to believe that a 1/3 size vertical dipole should perform so poorly compared to the least optimal 1/4 vertical installation imaginable! Yet, he's done A/B comparisons against the GAP and his vertical on recieved signals and on transmit and he uniformly get's poor results. We run a sked every Sunday on 40 m, and his 1/4 vertical just pummels the GAP. On other bands, he has not noted any such degradation in receive performance when comparing the GAP to his vertical. This is a realtively new antenna, debuted at Dayton. Has anyone else used one and noticed this? Is this a fluke? Any ideas/suggestions will be appreciated. Kim Elmore, [N5OP, PP ASEL/Glider 2232456] * _._. __._ _.. _.._ _.. . _. ..... ___ .__. _. ..... ___ .__. _.. _.._ _._ * * Said by NQ0I while working on his shack: * * "All these *wires*! Why do they call it `wireless'!?" * * _._. __._ _.. _.._ _.. . _. ..... ___ .__. _. ..... ___ .__. _.. _.._ _._ * ------------------------------ Date: 27 Jun 1994 17:25:23 GMT From: src.dec.com!crl.dec.com!nntpd.lkg.dec.com!nntpd2.cxo.dec.com!specxn.enet.dec.com!bonomo@decwrl.dec.com Subject: GPS group purchase shutdown To: ham-ant@ucsd.edu Greetings, all. As I have not achieved critical mass in the number of orders for the Motorola GPS engines, I am shutting down the group purchase. I am on vacation for the next two weeks. If, upon returning, there has not been enough orders received to reach the magic 100 mark, I will be returning the checks to those who have sent them to me, and discontinuing any efforts in this area. As of now, I have orders for about 35 units. For those of you interested, that's about $13,000 sitting on my desk. Thanks for your time, efforts and wonderful interest in this matter. Regards, Tom Bonomo ------------------------------ Date: Tue, 28 Jun 94 00:13:14 PDT From: ihnp4.ucsd.edu!usc!cs.utexas.edu!convex!news.onramp.net!usenet@network.ucsd.edu Subject: GPS group purchase shutdown To: ham-ant@ucsd.edu I'm still intetested if it counts. chasnged email addr since your original... -gc ------------------------------ Date: Tue, 28 Jun 1994 04:42:10 GMT From: news.Hawaii.Edu!kahuna!jeffrey@ames.arpa Subject: GPS group purchase shutdown To: ham-ant@ucsd.edu In article <2un223$4go@nntpd2.cxo.dec.com> bonomo@specxn.enet.dec.com () writes: > >I am on vacation for the next two weeks. .... > For those of you interested, that's about $13,000 >sitting on my desk. Uh oh... Wonder if he's going to Las Vegas? ;) Jeff NH6IL ------------------------------ Date: Tue, 28 Jun 94 00:08:41 PDT From: ihnp4.ucsd.edu!swrinde!cs.utexas.edu!convex!news.onramp.net!usenet@network.ucsd.edu Subject: HF Mobile Antennas To: ham-ant@ucsd.edu Steve, cheapest, best...Hamstick! $15 or so for each band, but boy do they work. Saturday evening mobile in Dallas, 14.162 UX2HO 59 sigs. We chatted for abt 10 minutes as I was driving Stemmons freeway. I ALWAYS get comments...90% of the time when a station discovers that I am mobile they always comment on the great mobile signal. No joking! -G ------------------------------ Date: Mon, 27 Jun 1994 15:21:38 GMT From: ihnp4.ucsd.edu!galaxy.ucr.edu!library.ucla.edu!csulb.edu!csus.edu!netcom.com!vanwag@network.ucsd.edu Subject: J-Poles and Baluns To: ham-ant@ucsd.edu A week or two ago, there was a post concerning using baluns with VHF/UHF J-pole antennas. I need clarification and information as I would love to improve the performance of my dual-band J-pole. Which type of balun do I need (4:1, 1:1)? What is a good source for baluns for VHF/UHF freqs? Thanks for the help, George KE6EPC -- vanwag@netcom.com ------------------------------ Date: 27 Jun 1994 21:44:17 -0500 From: ihnp4.ucsd.edu!galaxy.ucr.edu!library.ucla.edu!agate!howland.reston.ans.net!gatech!udel!news2.sprintlink.net!news.sprintlink.net!bga.com!bga.com!nobody@network.ucsd.edu Subject: J-Poles and Baluns To: ham-ant@ucsd.edu In article , George Van Wagner wrote: >A week or two ago, there was a post concerning using baluns with VHF/UHF >J-pole antennas. I need clarification and information as I would love to >improve the performance of my dual-band J-pole. Which type of balun do I >need (4:1, 1:1)? What is a good source for baluns for VHF/UHF freqs? I just know what I have read ... an ARRL ant handbook from a few years ago recommended a 4:1 balun (from 50 to ~200, noting that jpoles are 200-600). The book showed a step up made out of coax.... short the braid at both ends of a electral halfwave of coax and connect to the braid from the shield. Tie the feed center to one end for one feed point, use the other center conductor for the other feed point. This seems to work well for me (including eliminating the rf on the coax). You can coil the halfwave as desired. milton -- Milton Miller KB5TKF miltonm@bga.com ------------------------------ Date: 27 Jun 1994 20:18:24 GMT From: ihnp4.ucsd.edu!usc!nic-nac.CSU.net!rdw@network.ucsd.edu Subject: need heathkit data To: ham-ant@ucsd.edu I am seeking a source for manuals for the following Heathkit products: HW-16 Transceiver HW-13 VFO Does anyone have a source or possibly have these manuals for sale? Thanks in advance for any help. KE6FDU ------------------------------ Date: Mon, 27 Jun 1994 11:09:00 GMT From: ihnp4.ucsd.edu!agate!howland.reston.ans.net!newsserver.jvnc.net!yale.edu!noc.near.net!usenet.elf.com!rpi!psinntp!arrl.org!zlau@network.ucsd.edu Subject: Quadfiliar helix for GPS To: ham-ant@ucsd.edu Gary Coffman (gary@ke4zv.atl.ga.us) wrote: : Most GPS remote antennas are more than just an antenna. They almost : always include at least a preamp, and in some cases a complete down : converter assembly. That's because the small flexible coaxes used : have too great a loss at GPS frequencies to be overcome by just antenna : gain alone. That's why the antennas are expensive, they actually duplicate : circuitry in the receiver remotely at the antenna. Constructing such : circuitry at home is a rather advanced amateur technique. Unless you're : experienced at microwave construction, it's probably best to pay the : money for the factory remote antenna. One of the better descriptions of this antenna appears in Reflections by Walt Maxwell. I'd say it really doesn't belong here, but apparently this was one of Walt's specialties, so.... There are at least two MMICs designed to cover this frequency with noise figures below 2 dB--a Tri Quint semiconductor part that might be tough to get and the $8 Hewlett Packard MGA 86576 GaAs MMIC. The HP part has quite a bit of gain, over 20 dB, so it can overcome perhaps 30 ft or so of RG-58/U coax loss. I'd probably go to RG-8 coax before trying to cascade MMICs for longer coax runs--too much gain and you start having to worry about interference and stability problems. -- Zack Lau KH6CP/1 2 way QRP WAS 8 States on 10 GHz Internet: zlau@arrl.org 10 grids on 2304 MHz ------------------------------ Date: Mon, 27 Jun 1994 14:00:31 GMT From: mac_072.pppl.gov!user@princeton.edu Subject: Switching Relays for Ladder Line? To: ham-ant@ucsd.edu Hi, gang! As part of an effort to install a better antenna system, I would like to build a box containing relays and terminals so that I can select several antennas, each fed with 450 ohm ladder line. Has anybody in the group built such a unit? Are double-pole relays suitable for ladder line available anywhere? I can recall that in the 1950's I used a relay with a square ceramic base to switch my twin-lead transmission line between my station transmitter and receiver, but I don't recall the model or number. All the commercial antenna switching units appear to be designed for coaxial cable. Any tips or suggestions would be much appreciated! 73, George NJ2P Standard disclaimer: The above posting does not represent the views of Princeton University or the Plasma Physics Laboratory. ------------------------------------------------------------------------------ George B. Christianson | INTERnet: gchristianson@pppl.gov Princeton University | Phone: (609)-243-3270 FTS: 340-3270 Plasma Physics Laboratory | Amateur Radio: NJ2P P.O. Box 451 | Princeton, NJ 08543, USA ------|---------------------------------------------- ------------------------------ Date: Tue, 28 Jun 1994 05:59:37 GMT From: ihnp4.ucsd.edu!usc!cs.utexas.edu!convex!news.onramp.net!news.sprintlink.net!mv!mv.mv.com!tetrault@network.ucsd.edu Subject: Thick Ethernet cable To: ham-ant@ucsd.edu To: westgj@norand.com In a recent msg, you wrote, > >I would like to point out that you can test unknown coax with a wattmeter, a >dummy load and a VSWR bridge. > >If the loss is reasonable (check specs for "real" coax) and the VSWR is >really low then you know that it can be used successfully for RF purposes. > >Remember to check it out at or above the frequency you intend to use it on. >Advice for the day: Never walk away from gift coax. Agreed. I use Thick Ethernet Coax for ALL my 2m 440m antennas, including a very successful satellite (modeB) station. It is 50ohm, low loss stuff. Blue jacket, 2 foil and 2 braid shields, foam inner and solid copper tinned conductor. Loss is less than 9913 but more than 3/4" helix. NEVER overlook used Ethernet stuff. 73 Mark --- * UniQWK v3.3a* The Windows Mail Reader -- ------------------------------------------------------- | Mark D. Tetrault | tetrault@mv.mv.com | | 6 Colonial Drive | 1:132/169@fidonet.org | | Pembroke, NH 03275 | n1men.ampr.org_44.52.7.8 | | (603) 485-5852 | Have a Nice Day! | ------------------------------------------------------- ------------------------------ Date: 27 Jun 1994 12:06:06 -0500 From: ihnp4.ucsd.edu!swrinde!howland.reston.ans.net!vixen.cso.uiuc.edu!newsrelay.iastate.edu!hobbes.physics.uiowa.edu!news.uiowa.edu!norand.com!westgj@network.ucsd.edu Subject: Thick Ethernet cable in place of RG cables ??? To: ham-ant@ucsd.edu I would like to point out that you can test unknown coax with a wattmeter, a dummy load and a VSWR bridge. If the loss is reasonable (check specs for "real" coax) and the VSWR is really low then you know that it can be used successfully for RF purposes. Remember to check it out at or above the frequency you intend to use it on. Some off brand coax I have found is a little hard to connectorize. Sometimes it doesn't have exactly standard dimensions. Usually, particularly for use at HF you can make something work. Advice for the day: Never walk away from gift coax. Guy N0MMA westgj@norand.com ------------------------------ Date: 27 Jun 1994 10:10:16 -0500 From: ihnp4.ucsd.edu!usc!howland.reston.ans.net!cs.utexas.edu!geraldo.cc.utexas.edu!doc.cc.utexas.edu!not-for-mail@network.ucsd.edu To: ham-ant@ucsd.edu References <2uh1bh$lb4@news.u.washington.edu>, , s.e Subject : Re: A Question on Yagi's. Alec- Call the station Chief Engineer and ask him what type of polarization they are transmitting...Then get the ARRL antenna Book and wind a Helical antenna (guessing that it is going to be circuliar) using Wooden dowels as the Boom and standoffs. (you will need a calculator to do the dimentions) Go about..10 turns. This will look wild!...and operate great! Then...You Buy a radio shack Antenna preamp..bullet type..and put it at the antenna. Then...run RG-8x or better (belden 9913) for as short as possible to the receiver. You will be running the absolute optimum setup which should be able to routinely drag that signal in from 200 miles out. Your receiver better be decent..or else this will all be for naught. If you feel whimpy, just buy a commercial FM Yagi and do everything else I said. Oh yes, the Loop Yagi is not a circular antenna..I run a 55 element one at 87' with a Preamp into 7/8" heliax coax...Its like aiming a rifle! Good Luck- Bob AA5PB ------------------------------ End of Ham-Ant Digest V94 #202 ******************************