Date: Tue, 12 Apr 94 04:30:12 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 #100 To: Ham-Ant Ham-Ant Digest Tue, 12 Apr 94 Volume 94 : Issue 100 Today's Topics: ---TUNER ADVICE NEEDED--- Antenna materials... Best Mobile Antenna for Dual band (2m/70cm) rigs?? Comparison of mobile HF: Hustler/Bugcatcher/Others?? (2 msgs) eggbeater plans? help.. Ladder Line (2 msgs) Need apartment-dweller "stealth" HF ant Temporary HF Mobile ant? (3 msgs) Updated index to NEC ftp archives 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: 11 Apr 94 04:42:27 EST From: ihnp4.ucsd.edu!usc!sol.ctr.columbia.edu!newsxfer.itd.umich.edu!gumby!wmichgw!x90galbrait1@network.ucsd.edu Subject: ---TUNER ADVICE NEEDED--- To: ham-ant@ucsd.edu Hello, I am planning to erect a full wave 80m delta loop and use balanced transmission line for the first time (hurrah-I know). Also, this will require another first-a transmatch. What type of 2kW transmatch is the best in your opinion (make, model, etc...) and why? What sort of balun should be used if there is no internal one? Is there any non-roller inductor transmatches available besides the nye-viking $700 or Ameritron $400 ones??? (I can only afford around $200) Do you have one for sale??? Thanks for your help! Chris, KA8WFC ------------------------------ Date: 11 Apr 1994 16:17:44 GMT From: dog.ee.lbl.gov!agate!howland.reston.ans.net!europa.eng.gtefsd.com!news.umbc.edu!eff!news.kei.com!yeshua.marcam.com!charnel!olivea!koriel!lll-winken.llnl.gov!s07.es.llnl.@ihnp4.ucsd.edu Subject: Antenna materials... To: ham-ant@ucsd.edu A friend of mine made a 20 meter J-pole antenna out of electrical conduit for field day. Yes I said 20 meter J-pole. It was hung from a very tall tree and connected to a QRP rig. It worked fine, although they used a delta loop for most of their contacts. Steven Hunter ------------------------------ Date: Mon, 11 Apr 1994 11:15:52 GMT From: ihnp4.ucsd.edu!pacbell.com!att-out!cbfsb!cbnewsf.cb.att.com!cropley@network.ucsd.edu Subject: Best Mobile Antenna for Dual band (2m/70cm) rigs?? To: ham-ant@ucsd.edu well I took the plunge and bought a Yaesu FT530 at a feast yesterday Any body out there recommend a good dual band antenna (preferably Mag mount)?? Thanks, Andy C acropley@attmail.att.com ------------------------------ Date: Mon, 11 Apr 1994 18:45:02 GMT From: ihnp4.ucsd.edu!pacbell.com!amdahl!netcomsv!netcom.com!dgf@network.ucsd.edu Subject: Comparison of mobile HF: Hustler/Bugcatcher/Others?? To: ham-ant@ucsd.edu Has anyone done a comparison of HF antenna efficiency? I'm using a hustler on 40M & 20M, and wonder if the efficiency improvement (presumably...) would justify changing. Would appreciate info/pointers to article(s). 73 Dave WB0GAZ ------------------------------ Date: 12 Apr 94 05:52:03 GMT From: dog.ee.lbl.gov!agate!howland.reston.ans.net!noc.near.net!news.delphi.com!usenet@ucbvax.berkeley.edu Subject: Comparison of mobile HF: Hustler/Bugcatcher/Others?? To: ham-ant@ucsd.edu David Feldman writes: >Has anyone done a comparison of HF antenna efficiency? I'm using a hustler >on 40M & 20M, and wonder if the efficiency improvement (presumably...) would >justify changing. Would appreciate info/pointers to article(s). 73 Dave WB0GAZ Hi Dave, read what Maxwell says about Hustler resonators in "Reflections". The loading coil needs to be a large diameter with at least a wire diameter spacing between turns for high Q. If money is no object, you can hardly do better than a mobile antenna like the Texas Bugcatcher. Here's a statement sure to draw some flames. Since the radiation resistance of a 40m mobile antenna is around three ohms, if you can get your SWR up to 17/1, you will radiate most of your RF, unlike 40m mobile installations with an SWR of 1/1. Assuming a functional 40m mobile antenna (no shorts, no opens) the higher the SWR, the better. Use an antenna tuner to make your transceiver happy. A 40m loading coil with a Q=50 has a coil resistance of around 36 ohms. Add 10 ohms of ground loss and 3 ohms of radiation resistance and you have a perfect 1/1 SWR. Unfortunately, only about 6% of your RF energy actually gets radiated. Now put in a 40m loading coil with a Q=300 and a resistance of 6 ohms. The SWR is 3/1 but you are radiating 16% of your RF energy which is pretty good for 40m mobile. This is my opinion only, but I am convinced that the smaller the loading coil inductance, the better... as long as your antenna tuner and feedline have neglible losses and can furnish a conjugate match to the antenna system. 73, Cecil, kg7bk@indirect.com ------------------------------ Date: Mon, 11 Apr 94 12:37:29 -0500 From: news.bu.edu!noc.near.net!news.delphi.com!usenet@purdue.edu Subject: eggbeater plans? help.. To: ham-ant@ucsd.edu I remember seeing an article, possible in tech topics..., in QST with the basic design for an "eggbeater" antenna for 2m or 70cm. The antenna was very similar to the MC^2 systems eggbeater but i think that it was square. This is neither of the asat ants in the sat experimenters hbook, and i do not think that it is in the ARRL ant hbook. Any help would be greatly appreciated as i am becomming(argh, sp.) about ..... rather obsessive aboout homebrewing one. thanks Pete, N1QDQ ------------------------------ Date: 11 Apr 94 14:38:45 GMT From: ihnp4.ucsd.edu!agate!howland.reston.ans.net!vixen.cso.uiuc.edu!aries!wangc@network.ucsd.edu Subject: Ladder Line To: ham-ant@ucsd.edu cdsorens@mtu.edu (Christopher D. Sorensen) writes: >Where does one aquire 450ohm transmission quality ladderline? I have seen in >included in those over priced dipole kits, but I haven't found it anywhere sold >sepperatly. Is there a suitable substitute? Has anyone tried the stuff for >roof mounted TV antennas? Will that type of ladder line work? >I have heard many people talk about making their own ladder line. Can anyone >offer some suggestions on how to make your own ladder line? >Thanks >Chris -=- N8PBI Almost any Ham radio dealer has it. Buy it from Radio Works, 804-484-0140. You can get 2.5 inch ceramic spacers from Fair Radio, 4 for $1.25. They also have the Birnbach ceramic antenna center insulator (nice). 419-223-2169. Chuck, KE9UW 73 .. ------------------------------ Date: 11 Apr 1994 22:45:36 GMT From: ihnp4.ucsd.edu!usc!elroy.jpl.nasa.gov!ncar!noao!math.arizona.edu!news.Arizona.EDU!nelson.as.arizona.edu!hlester@network.ucsd.edu Subject: Ladder Line To: ham-ant@ucsd.edu In article <2o5ab6$71o@pace2.cts> cdsorens@mtu.edu (Christopher D. Sorensen) writes: >Where does one aquire 450ohm transmission quality ladderline? I have seen in > The best antenna wire I've ever seen/used, including ladder line, is from The Wireman. (I just looked for his ad in April QST and it's not there!!) His ladder line is far superior to that sold by The Radio Works. He also "sells" a catalog with a lot of good information about wire and transmission line. Howard KE7QJ ------------------------------ Date: 10 Apr 94 08:31:30 GMT From: bobsbox.rent.com!spatula!ahm@rutgers.rutgers.edu Subject: Need apartment-dweller "stealth" HF ant To: ham-ant@ucsd.edu I'd like to put up a decent end-fed "stealth" antenna for use from my apartment. (Someone mentioned using magnet-wire?! I don't suppose that would hold up under 100 watts, would it?) I'd appreciate any suggestions, with regard to an antenna of this sort and creative ways to install it. Thanks, Andy N2FYE ------------------------------ Date: 11 Apr 94 09:27:42 EST From: usc!howland.reston.ans.net!usenet.ins.cwru.edu!magnus.acs.ohio-state.edu!cis.ohio-state.edu!pacific.mps.ohio-state.edu!ohstpy.mps.ohio-state.edu!miavx1!miavx3.mid.muohio.edu!@ihnp4.ucsd.edu Subject: Temporary HF Mobile ant? To: ham-ant@ucsd.edu In article <2o7ml6$cck@pace2.cts>, cdsorens@mtu.edu (Christopher D. Sorensen) writes: > Can anyone give some suggestions for a temporary mobile HF antenna. I will > be borrowing a car from the company I work for to use on my trip to Dayton > and would like to work HF on the way down. I have never worked HF mobile > because I didn't have a suitable rig untill now. I have an FT890 with the > automatic tuner. > > Can anyone reccomend a decent antenna for probably 40meters? or whatever > band is best for HF mobile. The installation must be temporary and not do > any damage to the car. (Ie: No big scratches)... I will probably be > picking up a good HF mobile antenna at Dayton for my personal vehical > but would sure like to get something on the air for the trip down. > > Any suggestions would be greatly appreciated! > > 73, Chris -=- N8PBI > I like the "Ham Stick" ($20). It is single-band, low wind load, inexpensive, and it works. Look-alikes are available ($14-$20) in many ham outlets. There are magnet bases, however I've never used one. The mount I use is home made, clamps under the rear bumper, and works reasonably well. Does better on higher bands than 40 but does reasonably well on 40. Haven't tried 75. On 40M, try MIDCARS (7258KHz) on your trip to Dayton. With the antenna I described, I worked Chicago, Indiana, Missouri, and Ohio-area stations down I-75, thru Knoxville, and over into western NC. I was happy ... at least for now. See you at Dayton? Have a good trip. 73 >< Carl K8NHE ------------------------------ Date: 11 Apr 94 15:48:25 GMT From: ihnp4.ucsd.edu!galaxy.ucr.edu!library.ucla.edu!agate!howland.reston.ans.net!vixen.cso.uiuc.edu!aries!wangc@network.ucsd.edu Subject: Temporary HF Mobile ant? To: ham-ant@ucsd.edu cdsorens@mtu.edu (Christopher D. Sorensen) writes: >Can anyone give some suggestions for a temporary mobile HF antenna. I will >be borrowing a car from the company I work for to use on my trip to Dayton >and would like to work HF on the way down. I have never worked HF mobile >because I didn't have a suitable rig untill now. I have an FT890 with the >automatic tuner. >Can anyone reccomend a decent antenna for probably 40meters? or whatever >band is best for HF mobile. The installation must be temporary and not do >any damage to the car. (Ie: No big scratches)... I will probably be >picking up a good HF mobile antenna at Dayton for my personal vehical >but would sure like to get something on the air for the trip down. >Any suggestions would be greatly appreciated! You can mount a 40M "Hamstick" antenna on a heavy duty trunk lip mount or a 3 or 4 heavy duty magnet mount. I have done it, and it works well. It is advisable to "guy" the antenna against the wind with some fishing line or weed eater line tied to each rear window somehow. Good luck. You'll like mobile...makes the time go faster. Stay alert to the traffic, and keep your eyes on the road all the time. 73 Chuck, KE9UW >73, Chris -=- N8PBI ------------------------------ Date: 11 Apr 94 17:11:58 GMT From: agate!dog.ee.lbl.gov!ihnp4.ucsd.edu!pacbell.com!amdahl!netcomsv!netcom.com!dgf@ucbvax.berkeley.edu Subject: Temporary HF Mobile ant? To: ham-ant@ucsd.edu In article <1994Apr11.092742.1@miavx3.mid.muohio.edu> clmorgan@miavx3.mid.muohio.edu (Carl Morgan) writes: >In article <2o7ml6$cck@pace2.cts>, cdsorens@mtu.edu (Christopher D. Sorensen) writes: >> Can anyone give some suggestions for a temporary mobile HF antenna. I will >> be borrowing a car from the company I work for to use on my trip to Dayton > >There are magnet bases, however I've never used one. The mount I use is I use one of these; it works well electrically (on center of roof of station wagon), but I suspect it will cause paint damage or scratches on removal (I have an old car so I don't care). >See you at Dayton? Have a good trip. ^^^^^^^^^^ NAAAHHHHH - ** HAVE FUN !! ** ------------------------------ Date: 11 Apr 1994 21:36:07 GMT From: koriel!male.EBay.Sun.COM!uranium!raymonda@ames.arpa Subject: Updated index to NEC ftp archives To: ham-ant@ucsd.edu The following lists the current contents of the NEC archive site at ftp.netcom.com ******************************************************************** (note: this was netcom.com previously, however anonymous ftp is now allowed only via ftp.netcom.com or alternatively netcom2.netcom.com through netcom12.netcom.com. The higher number machines are usually less busy) ******************************************************************** * The files are located at ftp.netcom.com in /pub/rander/NEC and are available via anonymous FTP. * Note that eam_demo.zip is a new listing. ----------------------------------------------------------------------------- NEC (Numerical Electromagnetic Code): All files with .Z prefix compressed with UNIX compress NEC2_Mac_.hqx.Z NEC2 executable for the Macintosh (in compressed .hqx format) from Barry Newberger (bsn@fusion.ph.utexas.edu) NEC2_Mac_README.txt Document file for Mac version of NEC2 nec2.sun4.dl.Z SUN4 executable (dynamically linked) of NEC2 compiled for 1000 segments from Weston Beal (weston@arrakis.ebay.sun.com) nc2s1500.sun4.Z SUN4 executable (statically linked) of NEC2 compiled for 1500 segments from John Boyer (john.boyer@rd.eng.bbc.co.uk) nec2.rs6000.Z IBM RS/6000 executable of NEC2. Runs under AIX 3.2 from Doug Braun (dbraun@iil.intel.com) nec2.rs6000_readme.txt Document file for RS/6000 version of NEC2 mininec3.zip BASIC source code and DOS executable for mininec3 from NOSC nec2_src.tar.Z Fortran source code for NEC2 nec_param_util.Z Perl script to create NEC input files from parameterized physical descriptions. from Doug Braun (dbraun@iil.intel.com) nec_post_processor.Z Creates polar plots from NEC output. MS Quick Basic source code. from John Boyer (john.boyer@rd.eng.bbc.co.uk) nec81.tar.Z Fortran 77 source code for nec-81. (modified for 3000 segments) (Previously listed as nec3, but renamed to alleviate confusion with the real nec3.) (from Petri Kotilainen OH3MCK) nec81.readme.txt3 Readme file for nec-81. necdraw.zip DOS utility for verifying correctness of NEC models. Checks adherance to rules and provides 3-D display of model. (from ACES archive) nec_hist.txt Article from the ACES newsletter outlining the history of the various versions of NEC. eam_demo.zip EAM (electromagnetic antenna modeling) demo by SAIC (Science Applications International Corp.) Runs under Windows 3.1 (DOS). EAM is a graphical user interface to NEC and BSC. Demo version has limited capability but allows visualization and inspection of small to medium size input deck and output files. (from Malcolm_Packer@cpqm.saic.com) -------------------------------------------------------------------- ---------------------------------------------------------------------------- This response does not represent the official position of, or statement by, Sun Microsystems Incorporated. The above data is provided for informational purposes only. It is supplied without warranty of any kind. ---------------------------------------------------------------------------- /\ \\ \ \ \\ / / \/ / / Raymond E. Anderson WB6TPU / / \//\ Signal Integrity Engineer \//\ / / Sun Microsystems / / /\ / 2550 Garcia Ave. MS MIL04-16 / \\ \ Mountain View, CA 94043-1100 \ \\ \/ (408) 276-5224 (408) 956-0492 fax raymond.anderson@Sun.Com ------------------------------ Date: 11 Apr 1994 12:49:26 GMT From: ihnp4.ucsd.edu!swrinde!cs.utexas.edu!howland.reston.ans.net!europa.eng.gtefsd.com!news.umbc.edu!eff!news.kei.com!hookup!news2.sprintlink.net!news.sprintlink.net!indirect.com!patrick@network To: ham-ant@ucsd.edu References , <2o9dqm$8ne@herald.indirect.com>, <2o9qdg$865@crcnis1.unl.edu>fsd Subject : Re: Coax Loss on HF Gary McDuffie Sr (mcduffie@unlinfo.unl.edu) wrote: : Well, ladder line is one good idea. However, if you want to run coax, : do it. You will find it an advantage to have the antennas that far : from the house. You won't get into the tv/vcr/phone/intercom/etc. : nearly as much as you will with the antenna closer to the house. As If your system is properly installed, distance from the house has nothing to do with interference. Such things as poor connections on tower sections, poor joints on wires, etc., which set up rectification and radiate all over the spectrum, are going to effect your tv phone or other consumer devices at 350 ft just as much as at 0 feet. Witness the electric fence that destroys your communications from three or four miles away. Ladder line, being a BALANCED feedline, has nearly zero radiation. Even the best shielded coax has more. Pat KN7B ------------------------------ End of Ham-Ant Digest V94 #100 ******************************