Date: Sat, 6 Nov 93 04:30:21 PST 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 V93 #102 To: Ham-Ant Ham-Ant Digest Sat, 6 Nov 93 Volume 93 : Issue 102 Today's Topics: Antennas West (was Chimney mounting a triband beam?) Archery Advice for Antenna Raising Diamond X-500 Problem IsoPole Antennas (2 msgs) NEC modeling of ground effects 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: 3 Nov 1993 21:19:25 GMT From: swrinde!sdd.hp.com!vixen.cso.uiuc.edu!bradley.bradley.edu!augustana.edu!gganderson@network.ucsd.edu Subject: Antennas West (was Chimney mounting a triband beam?) To: ham-ant@ucsd.edu In article jayk@fc.hp.com (Jay Kesterson K0GU) writes: >From: jayk@fc.hp.com (Jay Kesterson K0GU) >Subject: Re: Chimney mounting a triband beam? >Date: Wed, 3 Nov 1993 14:44:55 GMT >>>Joe - N3PQY/AE >>>If this is doable, does anyone have a good source for high quality masts and >>>mounts like this? (Not Radio Shack!) > >Actually despite its looks the Radio Shack mount seems rather strong. >Its the only thing that kept the top 18 inches of my chimney from falling >off when a 75 MPH wind broke the chimney with a R5 vertical mounted on it. > >>Todd N9MWB >>Chimneys are not made to withstand the overturning forces that an antenna >>produces. > >I obviously must concur. > >73, Jay K0GU jayk@fc.hp.com How about the mounts from Antenna West? The ones advertised in 73 and that do not need guys or bolts. They use cinter blocks, either like 6 or 12 depending upon windload of antenna, in a rack to hold in place. Sounds good to me if you have a strong part of the roof to hold the weight, and maybe a rubber pad to put underneath. Don't own any stock, etc., with Antennas West, but they can be reached at 801-373-8425, Box 50062, S. Provo, Utah 84605 Can anyone comment on them? 73, Kevin kb9iua, gganderson@augustana.edu * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Kevin L. Anderson, Geography Dept., Augustana College Rock Island, Illinois 61201 USA phone: (309) 794-7325 e-mail: gganderson@augustana.edu or kla@helios.augustana.edu * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ------------------------------ Date: Thu, 4 Nov 1993 13:03:47 GMT From: mdisea!mothost!lmpsbbs!news@uunet.uu.net Subject: Archery Advice for Antenna Raising To: ham-ant@ucsd.edu In article 4307@tekgen.bv.tek.com, brucec@tekgen.bv.tek.com (Bruce Cheney) writes: } }I am about to put some rope through the trees using an arrow }with fish line attached to it. Anyone have any advice about }bows, arrows, archery for this purpose, attaching fish line, }paying the fish line out, etc ? } }If you do, I would appreciate hearing about it !! } }Bruce Cheney }NI7M }QTH: Sherwood, OR Well, it can be done - but it can be tricky. First, the arrow must have extra weight. Second, start with some lightweight twine, spool out what you think youy need in a half-circle in the direction of travel. Wear safety glasses!! I have had some bad experiences with this method because the acceleration of the arrow is so great. I've seen string spools snap the "stick" they were on and injure people. I've also seen the string cut the bow-string - and believ me, that is one wild reation when that snaps. I prefer using a fishing pole with 20lb test and about 3 oz of weight with some tape around it to soften it up some. I was able to easily cast over my 2 story townhome that way. Bruce, WB4YUC ------------------------------ Date: 1 Nov 1993 16:26 CST From: swrinde!cs.utexas.edu!TAMUTS.TAMU.EDU!zeus.tamu.edu!tskloss@network.ucsd.edu Subject: Diamond X-500 Problem To: ham-ant@ucsd.edu In article <4L5Bcc2w165w@vulcan.com>, kd4cim@vulcan.com (Jerry Pruett - KD4CIM) writes... >I have been using a Diamond X-500 dual-bander for a couple of years >and suddenly this week the SWR shot through the roof. The SWR would >waver but remained about 4:1. All the symptoms of bad feedline >(water?). Up we go with new feedline, new N-connectors - same >problem. We found a couple of inches of standing water in ours! Don't know where it came from though. -tim /------------------------------------------------------------------\ |* *(* (**)(* *)* *)*| Tim Skloss KC5DNA | |* * \/ \/ * *| Texas A&M University, Dept. of Chemistry | |* /=========\ *| College Station, TX 77843-3255 | |* | OXFORD | | LABORATORY FOR MAGNETIC RESONANCE | | | mags. | *| AND MOLECULAR SCIENCE | |* | RULE! | | voice: (409) 845-4459 | | |_________| | fax: (409) 845-4719 | | || || | Internet: TSKLOSS@venus.tamu.edu | | == == | My opinions do not reflect those of TAMU! | \------------------------------------------------------------------/ "The brain is much like a computer; therefore dumb people do not exist, just people running DOS!" PowerPC - The ULTIMATE personal computing machine. ------------------------------ Date: 5 Nov 93 19:50:28 GMT From: ogicse!uwm.edu!vixen.cso.uiuc.edu!howland.reston.ans.net!noc.near.net!news.delphi.com!usenet@network.ucsd.edu Subject: IsoPole Antennas To: ham-ant@ucsd.edu I'm shopping around for antennas and looking for opinions from the friendly, neighborhood antenna gurus. :-) Presently I'm using a Realistic HTX-202 handheld with a 5/8-wave mag-mount antenna inside the house. Needless to say it works great with most repeaters but simplex is practically out of the question. I currently live in a two-story house that has a TV beam mounted on the chimney (the antenna has been there forever but hasn't been used in years). At any rate, I'm going to remove the TV beam and mount a 2M omnidirectional antenna in its place -- of course I'm going to use all new mounts and coax. The question is which 2M antenna to use? I've been considering either a Ringo Ranger or an IsoPole and I've been hearing that the IsoPole is much better due to its lower angle of radiation. The specific uses I have in mind are primarily simplex and packet so I'm looking for as much distance as possible without going to a beam. Any opinions, criticisms and suggestions are much appreciated! -- Greg KE4DPX ------------------------------ Date: 5 Nov 93 23:53:48 GMT From: ogicse!uwm.edu!vixen.cso.uiuc.edu!moe.ksu.ksu.edu!crcnis1.unl.edu!unlinfo.unl.edu!mcduffie@network.ucsd.edu Subject: IsoPole Antennas To: ham-ant@ucsd.edu Greg Law writes: >I'm shopping around for antennas and looking for opinions from the >friendly, neighborhood antenna gurus. :-) > >Presently I'm using a Realistic HTX-202 handheld with a 5/8-wave mag-mount >antenna inside the house. Needless to say it works great with most repeaters >but simplex is practically out of the question. I currently live in a two-story >house that has a TV beam mounted on the chimney (the antenna has been there >forever but hasn't been used in years). At any rate, I'm going to remove the >TV beam and mount a 2M omnidirectional antenna in its place -- of course I'm >going to use all new mounts and coax. The question is which 2M antenna to use? >I've been considering either a Ringo Ranger or an IsoPole and I've been hearing >that the IsoPole is much better due to its lower angle of radiation. The >specific uses I have in mind are primarily simplex and packet so I'm looking >for as much distance as possible without going to a beam. > >Any opinions, criticisms and suggestions are much appreciated! > > -- Greg KE4DPX Just one man's opinion, but... The Ringo and IsoPole are probably about even, however I have not compared them side by side. I consider both of them slightly better than a dummy load. I have had several IsoPoles and don't think much of their ability to get a signal out, even less of their construction. If you opt for one, remember, they are ONLY rated at about 3db gain (not sure over what). You can come up with 3db gain with a few dollars worth of 50 ohm coax in a collinear. Increase the size of it and you can have more than that. Also, if you buy one, be sure to run a bead of silicon seal, or something simlar, on the lower edge of the foam doughnuts that stabilize the cones from underneath. This will keep them in place. In some cases, birds will peck them to pieces and they will no longer work. If that happens, get someone to cut a piece of plexiglas the right size to go up in the cones a few inches. This really works nice to keep all sorts of birds and small animals out of the cones. The cones MUST be stable. If they are lose or gone, the cones (made of nearly beer can quality aluminum) will move around in the wind and will break where they attach to the support mast. At that point, they are unrepairable. For the bucks, the Isopole is poor. There are LOTS of happy IsoPole users out there. I have never figured out why they are happy, but, many people swear by them. By the way, I have heard from many that the UHF version works very well and is of much better construction. Get next to one (where you can reach out and touch it) and look it over before you buy. I put a Diamond monobander up when the last IP bit the dust here. It works! 73, Gary ------------------------------ Date: Thu, 4 Nov 1993 01:47:36 GMT From: pa.dec.com!nntpd2.cxo.dec.com!nuts2u.enet.dec.com!little@decwrl.dec.com Subject: NEC modeling of ground effects To: ham-ant@ucsd.edu rkarlqu@scd.hp.com (Richard Karlquist) writes: >"NEC" (as opposed to "Mininec"). I thought that >PC's could only run Mininec and you needed a >workstation to run NEC. Can anyone confirm or NEC versus Mininec on PCs versus workstations is primarily an issue of addressing space. I would certainly think that the 32 bit C compilers available today could mung NEC into usable condition on a suitable PC, i.e. one with memory management such as a 386, 486, or later. Also, I'm sure the DECpc AXP 150 would have no trouble running NEC. :-) 73, Todd N9MWB ------------------------------ End of Ham-Ant Digest V93 #102 ****************************** ******************************