Date: Wed, 5 Oct 94 04:30:19 PDT From: Ham-Ant Mailing List and Newsgroup Errors-To: Ham-Ant-Errors@UCSD.Edu Reply-To: Ham-Ant@UCSD.Edu Precedence: List Subject: Ham-Ant Digest V94 #332 To: Ham-Ant Ham-Ant Digest Wed, 5 Oct 94 Volume 94 : Issue 332 Today's Topics: 'No ground' verticals? (3 msgs) 15m phased vertical array 5/8 wve 'mirror mount' wanted. Anybody ever use Phillystran "big grips"? 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, 4 Oct 1994 16:52:11 GMT From: dts@world.std.com (Daniel T Senie) Subject: 'No ground' verticals? In article <36ra19$dfq@nntp.hut.fi>, Jukka Tapio Sirvi| wrote: >In article acooney@netcom.com (Alan Cooney) writes: >>I'd like to make a 'no ground' vertical antenna for six meters (to > >The vertical doesn't need radials, if you make it 1/2 wave length long. You >have match the impedance though since it isn't 50 ohm (can't recall now >how much it is). > >Jukka OH6DD Commercial antennas include the Cushcraft AR-6 and a Diamond base/repeater antenna. The Cushcraft is 1/2 wavelength long, and is essentially similar to all the rest of the ringos. It works just fine. The Diamond is colliniar and is 21 feet tall. J- poles for 6 meters are not hard to build. Use a choke (sleeve) balun on the coax directly below the feetpoint for best results. A vertical dipole (bring the coax away at 90 degrees) also works well. Dan N1JEB -- --------------------------------------------------------------- Daniel Senie Internet: dts@world.std.com Daniel Senie Consulting n1jeb@world.std.com 508-779-0439 Compuserve: 74176,1347 ------------------------------ Date: 4 Oct 1994 10:16:09 GMT From: jsi@vipunen.hut.fi (Jukka Tapio Sirvi|) Subject: 'No ground' verticals? In article acooney@netcom.com (Alan Cooney) writes: >I'd like to make a 'no ground' vertical antenna for six meters (to The vertical doesn't need radials, if you make it 1/2 wave length long. You have match the impedance though since it isn't 50 ohm (can't recall now how much it is). Jukka OH6DD ------------------------------ Date: 4 Oct 1994 11:53:08 GMT From: moritz@ipers1.e-technik.uni-stuttgart.de () Subject: 'No ground' verticals? Alan, What you are looking for is a endfed half wave dipole. the problem with this setup is, that the feed point impedance is very high, and hence requires a well designed matching transformers. Commercial systems for 2 or 10 m are the Ringo antennas, where there is a one turn loop with adjustable tap at the lower end of the radiating element. An alternative are those 1/4 wl verticals with a coaxial sleeve instead of the radials. Beware of some designs like Jpoles, some of them require 50 Ohms symmetric feed. 73, Morritz DL5UH ------------------------------ Date: 4 Oct 1994 17:44:02 -0400 From: ricecakes@aol.com (Ricecakes) Subject: 15m phased vertical array I'm looking for a design for a 2 element 15m phased vertical array with 1/8 wavelength separation and 135 degree phasing (which according to the ARRL antenna book, would give me 4.2dB) ------------------------------ Date: 4 Oct 1994 13:01:10 GMT From: kedz@banach.WPI.EDU (John Kedziora) Subject: 5/8 wve 'mirror mount' wanted. Im looking for a 5/8 wave 2m antenna that'l mount on my truck's mirror, (the kind that are 6x10 with tubular supports above and below) Real estate on the roof is limited at best. Does anyone have/reccomend one? cost is important (i.e. low cost :)) please reply by e-mail. thanx~ John Wu3c (kedz@wpi.wpi.edu) ------------------------------ Date: Tue, 4 Oct 1994 16:11:18 GMT From: rossi@VFL.Paramax.COM (Pete Rossi) Subject: Anybody ever use Phillystran "big grips"? Anyone out there ever use the new "big grips" that are now available for Phillystran cable? They cost roughly double what the standard end kits cost. Is it worth the extra cost? ================================================================= Pete Rossi - WA3NNA rossi@vfl.paramax.COM Unisys Corporation - Government Systems Group Valley Forge Engineering Center - Paoli, Pennsylvania ================================================================= ------------------------------ Date: Tue, 4 Oct 1994 16:32:28 GMT From: dts@world.std.com (Daniel T Senie) References <36q6d6$s60$1@mhade.production.compuserve.com>, <36rleb$jjn@nntpd.lkg.dec.com> Subject: Re: Antennas are prohibited ...!!!!!!.. In article <36rleb$jjn@nntpd.lkg.dec.com>, Todd Little wrote: > >In article <36q6d6$s60$1@mhade.production.compuserve.com>, TI Forum <76701.203@CompuServe.COM> writes: >|>Don't WE think it is about time we come out of the ATTIC and >|>STAND up for our rights!!!!! >|>I am also stuck with antenna prohibitions. I would like to fight. >|>Alone it will not work ... but as a group!!!! >|>i think we need to lobby our elected officials. Gather support >|>from other Amateur Radio Operators in similar situations. >|>No I don't propose my home owners association allow me to put up >|>a 40M beam on a town house. or Stacked 15 element 2M beams. But >|> out the the ATTIC reduces RFI. >|>Well any one elese feel this way!!! > >Please feel free to lobby anyone and everyone. I've personally written >much of the League's hierarchy and the only really favorable response I >got was from Wilson. Sumner went out of his way to suggest that we need >to work with local officials and demonstrate our value. The fact that >the local RACES (of which I'm an active member), and many disaster related >agencies spoke on our behalf, the local egomaniacs (you know, our local >elected government) still felt that our town shouldn't live under the >specter of high or large or numerous antennas. Dealing with a bunch >of self appointed demi-gods doesn't always work. > >Personally I beleive this is one of the biggest threats to amateur radio, >but I guess those that already have their contest station antenna farms >don't have to worry about it. It is interesting to read nearly identical threads over in rec.video.satellite as people start exploring the new small-dish satellite TV, only to discover that their towns prohibit ALL outside antennas. In the case of TV, this makes the Cable TV company a virtual monopoly (guess who pushed for such regulations in many towns?). As the fight for TV roof antennas and dishes moves forward, it is important for the hams to be there supporting in the fight. Ideally, we need to get all such ordinances, covenants, etc. removed, and the vehicle to get them gone may well be the "Information Superhighway". Much of the future of communications will be wireless, be it satellite or terrestrial, and antennas will have to be a part of the landscape. Dan N1JEB -- --------------------------------------------------------------- Daniel Senie Internet: dts@world.std.com Daniel Senie Consulting n1jeb@world.std.com 508-779-0439 Compuserve: 74176,1347 ------------------------------ Date: 4 Oct 1994 04:44:45 GMT From: buster@usr1.primenet.com (Lou Nigro) References <36iluf$shi@news.primenet.com>, <36pl01$1cq@chnews.intel.com> Subject: Re: using twin coax vs ladder line Tom WB7ASR (tom_boza@ccm.hf.intel.com) wrote: : Lou : At the bauln outside your house, I assume your tieing the center : conductor of each coax to the bauln's output terminals, however what do you do : with the sheilds, tie them together to ground or let them float? When you run : the two coax cables to the antenna, did you just tape them together? Is there : any critical spacing? At the feed point of the antenna, does the sheilds float? : Did you use 50 or 75 ohn coax, or doesn't it matter? : This idea sounds interesting, I have a ton of 50 ohm surplus coax and I might : give it a try. Tom - The center conductors are connected to the baluns output terminals and the grounds at the bauln end are grouded. The bauln is enclosed in a metal box that has 3 SO-239 connectors on it, 1 for the input to the bauln from the tuner, and the other 2 for the balanced outputs from the bauln. At the antenna end, the shields are tied together and not connected to anything else. No critical spacing, and you can run the coax wherever you want to, even bury it if you must. I used RG-8/U, you can use 75 ohm stuff as well with a change in impedance. 50 ohm coax will have an impedance of about 100 ohms, 75 ohm coax will be about 150 ohms. The new ARRL antenna book has a short writeup on shielded parallel lines, page 24-18. Losses will be higher than with open wire, but I have a short run and reduced noise, longer life, and easier installation of the feed line more than make up for this in my case. The feedline has been in use for 10+ years in Tucson and it is still working just fine. The antenna, a full wave horizontal delta loop cut for 80 meters, is used on 40 meters as well, on occasion with a Drake L4B linear with no problems at all. Lou Nigro - KW7H -- --------------------------------------------------------------- Water can be toxic if you hold your head under it long enough - ------------------------------ Date: Tue, 4 Oct 1994 19:31:10 GMT From: zlau@arrl.org (Zack Lau (KH6CP)) References <36q6d6$s60$1@mhade.production.compuserve.com>, <36rleb$jjn@nntpd.lkg.dec.com> Subject: Re: Antennas are prohibited ...!!!!!!.. Todd Little N9MWB (little@iamu.chi.dec.com) wrote: : Please feel free to lobby anyone and everyone. I've personally written : much of the League's hierarchy and the only really favorable response I : got was from Wilson. Sumner went out of his way to suggest that we need : to work with local officials and demonstrate our value. The fact that : the local RACES (of which I'm an active member), and many disaster related : agencies spoke on our behalf, the local egomaniacs (you know, our local : elected government) still felt that our town shouldn't live under the : specter of high or large or numerous antennas. Dealing with a bunch : of self appointed demi-gods doesn't always work. Some hams have solved this problem by serving on the town planning board to balance things out a little. : Personally I beleive this is one of the biggest threats to amateur radio, : but I guess those that already have their contest station antenna farms : don't have to worry about it. It seems that the hams who have done poorly in court cases haven't stacked the deck in their favor by spending a lot of time on emergency/public service activities. For example, the people at the South Pole really appreciate phone patches back home--something you usually need a really big 20 meter antenna to do well. -- Zack Lau KH6CP/1 2 way QRP WAS 8 States on 10 GHz Internet: zlau@arrl.org 10 grids on 2304 MHz ------------------------------ End of Ham-Ant Digest V94 #332 ******************************