Date: Tue, 21 Dec 93 04:30:14 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 #149 To: Ham-Ant Ham-Ant Digest Tue, 21 Dec 93 Volume 93 : Issue 149 Today's Topics: 6m portable advice Antenna Tuner Questions Commercial Antenna Tuners Hamfest License need ht antenna recommendation (mobile and base) 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: Mon, 20 Dec 1993 20:30:38 GMT From: dog.ee.lbl.gov!newshub.nosc.mil!news!usenet@network.ucsd.edu Subject: 6m portable advice To: ham-ant@ucsd.edu I'm getting more and more interested in 6m SSB. I use an M2 Sqloop now, but want an antenna I can use for drive-up hilltop portable use. I have a Bronco II with a pair of Yakima bars for a rack where I carry the antennas when we contest rove or just go and set up somewhere with a view. I told you that so you'd be able to consider my constraints and cababilities. What antennas have you had luck with on 6m (50.1 SSB/CW) which are suitable for portable use? What about pre-amps? Which ones and why? Have you had trouble with other antennas mounted on the same mast causing interference? Note that I'm not doing EME here, just hilltop DX for contests and general fun. My rig is a TS-690. I'm considering an amp too, but the antenna is first. Antennas I'm considering include: + M2 beam (which one? anyone own the short ones?) + Bandmaster Quad ( I like the 432 6elem quad I bought from them.) + Something I'll build. Still gathering plans and ideas. I don't have a shop or many tools so, I'm a bit limited in my building capabilities. However, I'm considering a wooden boom. Remember this is NOT a permanent installation and will only have to cope with wx I am willing to cope with. email comments, or post. I'll collect and post interesting comments I get. Thanks for your interest. email to: keating@nosc.mil Roger - KD6EFQ _ . _ _ . . _ . . . . . . . _ . _ _ . _ . . . _ . _ Roger Keating, Cognitive Engineer PS&E keating@nosc.navy.mil | KD6EFQ Naval Command, Control and Ocean Surveillance Center RDTE DIV | VHF DX is NRaD Advanced Afloat System HCI - Code 44209 | Fun! 53245 Patterson Rd, San Diego CA 92152-7150 USA | Try it. ------------------------------ Date: 19 Dec 93 03:38:16 GMT From: psinntp!iat.holonet.net!rohrwerk@uunet.uu.net Subject: Antenna Tuner Questions To: ham-ant@ucsd.edu kg7bk@indirect.com (Cecil Moore) writes: >I am teaching a ham class and have been asked questions that I can't >answer (not unusual) but I can't find the answer in the Handbook or >Antenna Book... Here they are: [items axed] >3. What is the transfer function of a transmission-line transformer type >Balun? i.e. Does a 4:1 Balun transform 1000 +j1000 to approximately >250 + j250 or is it like the coax series-section transformer equations? >thanks, Cecil, kg7bk@indirect.com A nice theoretical question. Just a thought on the practical level: from what I've read, the use of transmission line "baluns" on the output of antenna tuners is absurd when matching reactive loads, like using a dipole fed with balanced line on several bands. Feb. 1990 QST deals with a tuner that puts the balun (1:1, current-type) on the INPUT so you don't have to deal with this. There are some other articles I remember somewhere about the behavior of transmission-line transformers with reactiv3e loads, but can't place them. What your students should really hear is that your typical commercial antenna tuner with the balun on the output is taking the cheap way out. It may work after a fashion, but if you do it right ( a true balanced tuner, one example of which is the item referred to above), you will have a non-radiating balanced feedline, and a good multiband antenna system (if you don't mind twiddling with knobs). John K0JD ------------------------------ Date: 20 Dec 93 23:20:26 GMT From: ogicse!uwm.edu!cs.utexas.edu!sdd.hp.com!col.hp.com!srgenprp!alanb@network.ucsd.edu Subject: Commercial Antenna Tuners To: ham-ant@ucsd.edu Charles R. Hohenstein (Charles.R.Hohenstein.1@nd.edu) wrote: : Are there any balanced tuner designs commercially available? What is the : Johnson Matchbox, which is frequently mentioned in the rec.radio : newsgroups? I'm not up on currently-available tuners but, as a certified "old fart," I can comment on the Johnson Matchbox. :=) It's basically a tuned circuit with a link-coupled output, as I recall. Its big advantage over most modern tuners is that it has a true balanced output, without the need for an external balun. If you are feeding twinlead or open-wire feedline, the Matchbox is the hot ticket. It can also work with coax output by shorting one side of the link to ground. : As described by MFJ, the 986 differential T tuner certainly sounds : convenient--only two adjustments to make, only one optimum setting instead : of multiple dips. Does it work as well in practice as in theory? IMO, a T-network is an excellent way to go, in the following arrangement: Variable Variable Radio ------- Capacitor -------*------- Capacitor -------- Antenna | Bandswitched Inductor | Ground It has a wide matching range, for both high and low load impedances and requires no variable inductor. The one disadvantage is that it does little to attenuate harmonics, being a high-pass structure. However, most tuners do little to attenuate VHF harmonics (the ones that cause TVI) anyway, so I don't consider that to be much of a disadvantage. AL N1AL ------------------------------ Date: 20 Dec 93 16:29:10 GMT From: vnet.IBM.COM@uunet.uu.net Subject: Hamfest To: ham-ant@ucsd.edu I thought someone told me there is to be a hamfest in Yonkers in January, but I don't see it listed in ARRL's HAMFEST-USA file. Can someone tell me if there is such a hamfest, and its time and place? Regards, Evan Jennings ------------------------------ Date: Mon, 20 Dec 1993 15:25:09 GMT From: uunet.ca!uunet.ca!dmog10.bell.ca!news@uunet.uu.net Subject: License To: ham-ant@ucsd.edu In article <2esgu1$8f4@dancer.cc.bellcore.com> whs70@dancer.cc.bellcore.com (sohl,william h) writes: >In article <16CA76B51S85.R3RLB@VM1.CC.UAKRON.EDU>, > wrote: >>I am interested in getting a radio license and don't what to do or where to >Call the ARRL (Amateur Radio Relay League) at 1-800-326-3942 and they'll >send you a "New Ham" info package with contact information, etc. > >You can also immediately order the license manual for Novice and Technician >class licenses by calling the ARRL order line at 1-203-666-1541. >The license manual/study guide is: "Now You're Talking", item #4173, $19. > I would be interested in this too..... Is this ARRL and the Phone nos. valid for us in the Great White North? I haven't come across a Canadian group yet, but then I don't know where to look etiher. ------------------------------ Date: Tue, 14 Dec 1993 17:36:58 -0600 From: swrinde!cs.utexas.edu!math.ohio-state.edu!magnus.acs.ohio-state.edu!usenet.ins.cwru.edu!agate!dog.ee.lbl.gov!hellgate.utah.edu!cc.usu.edu!NewsWatcher!user@network.ucsd.edu Subject: need ht antenna recommendation (mobile and base) To: ham-ant@ucsd.edu I'd like to get recommendations on 2m antenna for use with an ht for base, mobile and as a portable. I have read recommendations on the AEA hotrod ($25) for rubber duck replacement. I am thinking on using this for home, portable and mobile use (using one of those bnc clips over the car window glass). any comments ? the AES store seems to be pushing their Diamond line of mobile antenna. the antenna itself cost like $30, but the mount cost $50 (I think). any comments/recommendations on mobile antennas ? also for base antenna for use at home (apartment). please email replies if possible. thanks in advance. jerry ------------------------------ End of Ham-Ant Digest V93 #149 ****************************** ******************************