Date: Tue, 19 Apr 94 04:30:24 PDT From: Ham-Homebrew Mailing List and Newsgroup Errors-To: Ham-Homebrew-Errors@UCSD.Edu Reply-To: Ham-Homebrew@UCSD.Edu Precedence: Bulk Subject: Ham-Homebrew Digest V94 #103 To: Ham-Homebrew Ham-Homebrew Digest Tue, 19 Apr 94 Volume 94 : Issue 103 Today's Topics: cheap 6-meters? HELP!! Looking for info on Kenwood TR-7625 RF sensing T/R switch Spec sheets needed for Sony, NPC... Varactor diodes (2 msgs) Wanted: TNC plans or kit 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-Homebrew Digest are available (by FTP only) from UCSD.Edu in directory "mailarchives/ham-homebrew". 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: 18 Apr 1994 23:48:56 GMT From: ihnp4.ucsd.edu!swrinde!emory!news-feed-2.peachnet.edu!hobbes.cc.uga.edu!news.uga.edu!jgifford@network.ucsd.edu Subject: cheap 6-meters? To: ham-homebrew@ucsd.edu I recently got my hands on a "Space Patrol" walkie talkie. It is at 49.8 MHz I think. Does anyone know of a cheap and easy way to get the thing into the 6meter band? I figure if it works OK, I can get a little linear that puts out a few (<10) watts and use the local experimental repeaters. Thanks in advance! Jim KD4PPG ------------------------------ Date: Mon, 18 Apr 1994 22:15:09 GMT From: ihnp4.ucsd.edu!sdd.hp.com!hpscit.sc.hp.com!cupnews0.cup.hp.com!news1.boi.hp.com!hess@network.ucsd.edu Subject: HELP!! Looking for info on Kenwood TR-7625 To: ham-homebrew@ucsd.edu I purchased a Kenwood TR-7625 at Auction. It is a synthesized 2M rig, and is working. I need a manual for it. Looks like it was built between 1975 and 1980. It has no DTMF, and I would like to have suggestions on a microphone with a DTMF pad and encoder I could put on the radio. The microphone connector is a five pin style. I called Kenwood, they have no manuals and have no suggestions on where to go for help. To any who have a manual, I will gladly pay costs for photocoping, etc. Thanks much for your time. Maybe I can return the favor to you some day. -- The statements/opinions expressed here are not necessarily those of the Hewlett-Packard Company. HP paid a research firm millions of dollars to get their own opinions, and has made it clear they do not wish to share mine. Kevin C. Hess (KB7UKR) Hewlett-Packard Network Printer Division hess@hpdmd48.boi.hp.com (208) 396-3384 Boise, Idaho 83704 Are we at last brought to such humiliating and debasing degradation, that we cannot be trusted with arms for our defense? ... If our defense be the _real_ object of having those arms, in whose hands can they be trusted with more propriety, or equal safety to us, as in our own hands? - Patrick Henry ------------------------------ Date: 18 Apr 1994 23:52:00 GMT From: ihnp4.ucsd.edu!usc!howland.reston.ans.net!gatech!udel!news2.sprintlink.net!news.sprintlink.net!bga.com!kbrune@network.ucsd.edu Subject: RF sensing T/R switch To: ham-homebrew@ucsd.edu Anyone out there messed around with an RF sensing T/R switch? I have been thinking of building one for an amp. Thanks in advance ... Ken WL7IR ------------------------------ Date: 18 Apr 94 17:11:09 -0600 From: ihnp4.ucsd.edu!sdd.hp.com!saimiri.primate.wisc.edu!news.doit.wisc.edu!uwec.edu!standimj@network.ucsd.edu Subject: Spec sheets needed for Sony, NPC... To: ham-homebrew@ucsd.edu Would anyone know where I could get the adresses for spec sheets from the following? Sony, Cardinal Components, and NPC? Im doing some work with digital audio and would greatly appreciate any response, phone numbers for the companies would be great too. Matt Standing KA9VJV standimj@cnsvax.uwec.edu Thanks in advance... ------------------------------ Date: 15 Apr 94 03:29:26 GMT From: agate!howland.reston.ans.net!vixen.cso.uiuc.edu!moe.ksu.ksu.edu!matt.ksu.ksu.edu!not-for-mail@ucbvax.berkeley.edu Subject: Varactor diodes To: ham-homebrew@ucsd.edu Hi: I'm attempting to make a very broadband synthesizer in the VHF range and I'm looking for some tuning diodes with LARGE tuning ratios. If anyone has any suggestions I'd be very interested. So far I've gotten 80 MHz to 180MHz with a fairly linear tuning curve. Beyond this the VCO response flattens out. I've got the system running now by misusing hyperabrupt low frequency varactors. These have two problems. Their Q is pretty horrible until you get a fair amount of reverse bias on them. Most are made over a 12V operating range. This gives some pretty massive VCO gains. I'm ideally looking for a high tuning ratio capacitor made for the VHF range. I also wouldn't mind a larger voltage operating range. Thanks in advance for any advice. nam mortense@matt.ksu.ksu.edu () When all you have is a hammer ... #######======|| ## ... everything looks like a nail! ------------------------------ Date: 15 Apr 94 03:53:39 GMT From: agate!howland.reston.ans.net!europa.eng.gtefsd.com!paladin.american.edu!constellation!osuunx.ucc.okstate.edu!olesun!gcouger@ucbvax.berkeley.edu Subject: Varactor diodes To: ham-homebrew@ucsd.edu In article <2ol1mm$506@matt.ksu.ksu.edu>, Alvin Nor Mortensen wrote: >Hi: > >I'm attempting to make a very broadband synthesizer in the VHF range and >I'm looking for some tuning diodes with LARGE tuning ratios. If anyone >has any suggestions I'd be very interested. > >So far I've gotten 80 MHz to 180MHz with a fairly linear tuning curve. >Beyond this the VCO response flattens out. I've got the system running >now by misusing hyperabrupt low frequency varactors. These have two >problems. Their Q is pretty horrible until you get a fair amount of >reverse bias on them. Most are made over a 12V operating range. This >gives some pretty massive VCO gains. I'm ideally looking for a >high tuning ratio capacitor made for the VHF range. I also wouldn't mind >a larger voltage operating range. > I saw an VCO in RF ??? 1990 sometime that used an electro-magnet to change the inductance of a coil on a ferrite Coil. It gave a great deal more range than capicators. Sorry about not rembering the name of the magizine It's a monthly publication well known and I am pretty sure the editors name is Gary. Of all the things I've lost I miss my mind the most. Good luck Gordon AB5DG >nam > >mortense@matt.ksu.ksu.edu > > () When all you have is a hammer ... > #######======|| > ## ... everything looks like a nail! > Gordon Couger Biosystems & Agricultural Engineering Oklahoma State University 114 Ag Hall, Stillwater, OK 74074 gcouger@olesun.agen.okstate.edu 405-744-9763 day 624-2855 evenings I do not speak for my employer ------------------------------ Date: Sun, 17 Apr 1994 23:24:16 GMT From: ihnp4.ucsd.edu!swrinde!gatech!newsxfer.itd.umich.edu!zip.eecs.umich.edu!panix!ddsw1!news.kei.com!ub!dsinc!netnews.upenn.edu!iat.holonet.net!vectorbd!jpll@network.ucsd.edu Subject: Wanted: TNC plans or kit To: ham-homebrew@ucsd.edu Rick Gilmore (rg36+@andrew.cmu.edu) wrote: : I have a Macintosh Powerbook 140 I'd like to use for packet. Could : someone point me toward plans or a kit for a TNC that would give me : basic packet capabilities? The BAYCOM Modem will hook to a Mac.. the rest of the TNC process gets done in the Mac itself. There's schemtics, drivers etc on many LLBBS for this. -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Jim Lill- Vector Board BBS jpll@vectorbd.com 716-544-1863/2645 wa2zkd@wb2psi.#wny.ny.usa.na GEnie: ZKD ------------------------------ Date: 18 Apr 1994 23:11:55 GMT From: ihnp4.ucsd.edu!library.ucla.edu!psgrain!news.tek.com!tekig6!dank@network.ucsd.edu To: ham-homebrew@ucsd.edu References <".9-Apr-94..6:, 34:05.PDT".*.D.R._Shalita.ES_AE@Xerox.com>, <1994Apr13.125524.4469@ke4zv.atl.ga.us> Reply-To : dank@tekig6.pen.tek.com Subject : Re: Frequency Counter Circuit Mod In article <1994Apr13.125524.4469@ke4zv.atl.ga.us> gary@ke4zv.atl.ga.us (Gary Coffman) writes: >In article <".9-Apr-94..6:34:05.PDT".*.D.R._Shalita.ES_AE@Xerox.com> David_Shalita.ES_AE@xerox.com writes: >>I would like to homebrew a circuit mod that inhibits freq display >>any time the input signal is below a minimum amplitude that >>I would select. >What you need is a Schmidt trigger circuit near the input stage, at least >before the counter ICs, if after the prescaler. For a 600 MHz counter, that >would be a 60 MHz Schmidt. The best bet is a Schmidt trigger, but it needs to be *before* the pre-scaler (the pre-scaler *is* a counter). Typical ECL flip-flops act transparent when the clock input is balanced, turning the input stage of your pre-scaler into a ring oscillator when the input signal is centered. A cheap Schmidt can be made using a fast ECL (10KH, ECLiPS, etc) line reciever with a resistive divider from the output to the positive input to provide hysteresis. Two such circuits in a row is somewhat better. As a "quick and dirty" fix, though, you could just add a little DC offset to the counter or pre-scaler input. (If the counter input is AC coupled, the DC offset needs to be inserted after the AC coupling, so that the pre-scaler IC sees the offset.) - Dan Knierim These opinions aren't worth the standard disclaimer form they're printed on! ------------------------------ End of Ham-Homebrew Digest V94 #103 ******************************