Date: Sat, 10 Sep 94 04:30:29 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 #269 To: Ham-Homebrew Ham-Homebrew Digest Sat, 10 Sep 94 Volume 94 : Issue 269 Today's Topics: 100MHz TTL Clock AG6K and this month's Tech Correspondence in QST EME amp (3 msgs) H.P. Digital Panbel Meters (2 msgs) Heeeeeeeeeeeelp! (3 msgs) ICOM 22S mod (repeater switch) Mitrek 800 Mhz Service Manual/ Info ?? need 100 MHz TTL clock SETIQuest Magazine - Exobiology unusual modulation techniques xtal filters 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: Fri, 09 Sep 1994 13:01:30 -0400 From: ihnp4.ucsd.edu!agate!howland.reston.ans.net!sol.ctr.columbia.edu!news.msfc.nasa.gov!niven.ksc.nasa.gov!algol.ksc.nasa.gov!k4dii.ksc.nasa.gov!user@network.ucsd.edu Subject: 100MHz TTL Clock To: ham-homebrew@ucsd.edu In article <2E6F304A@msmail.uthscsa.edu>, MUENZLERK@uthscsa.EDU (Muenzler, Kevin) wrote: > If you just need a 100MHz pulse rate, you can use any of the > 74Fxx or 74ALSxx series chips. They should have no problem > running at 100MHz. All you would need is the 100 MHz > crystal. Kevin- A 100 MHz crystal is most likely used in a fifth or seventh overtone mode. How do you ensure that the crystal oscillates at the correct overtone, instead of the fundamental or an "easier" overtone? 73, Fred, K4DII ------------------------------ Date: Thu, 8 Sep 94 19:37:18 GMT From: dog.ee.lbl.gov!agate!howland.reston.ans.net!gatech!newsxfer.itd.umich.edu!zip.eecs.umich.edu!yeshua.marcam.com!news.kei.com!ub!galileo.cc.rochester.edu!uhura.cc.rochester@ihnp4.ucsd.edu Subject: AG6K and this month's Tech Correspondence in QST To: ham-homebrew@ucsd.edu I was leafing through this month's QST magazine. The technical correspondence column made some very interesting reading. I had previously read the articles on VHF/UHF parasitics in HF amps, design of HF amps, design of balanced tuner and so on by Rich Measures in QST. His articles on these topics have also appeared in the now defunct Ham Radio Magazine. This month's Tech Correspondence column is devoted to a critical examination of Rich's theories. It has comments by an engineer from Eimac, an engineer who designs amps for ameritron and others. To put it mildly, it disagrees with Rich Measures. What did you think? On many points, it is clear that the critics are right. For instance, consider the anode parasitic supressor. The common form of it is a resistor with a coil wound around it. One of Rich's ideas is to make the coil out of nichrome wire (has some resistance) to prevent V/UHF parasitics. He sells this in kit form. But as the critics point out, At VHF/UHF the coil has high impedance and it is the resistor that is a part of the anode circuit, lowering its Q at those frequencies. The critics also disagreed about removing electronic drive control, alc, using improper protection in the HV section, using resistor in grid-ground circuit to introduce negative feedback to reduce gain and most seriously, about using MOVs in the HV circuit. While I tend to agree with the critics generally, several of them said that UHF/VHF parasitics are not a problem in most commercial amateur amps. My tiny experience in these things seems to be otherwise. I have seen amps with some of the symptoms that Rich Measures described. What has your experience been? Another curious point: If the article was so off the mark, what does it say about QST's editorial process. It is bad that it hapened but good that they own up to it? or what? In QST's defense, even the best of scientific journals have this problem. Honey, where is the salt shaker? I received this month's QST. :) Rajiv aa9ch/2 ------------------------------ Date: Thu, 8 Sep 1994 20:32:11 GMT From: agate!howland.reston.ans.net!europa.eng.gtefsd.com!newsxfer.itd.umich.edu!isclient.merit.edu!msuinfo!netnews.upenn.edu!news.drexel.edu!news.ge.com!knight.vf.ge.com!nadir!hbrown@ames.arpa Subject: EME amp To: ham-homebrew@ucsd.edu I've heard that Russian tubes are available. Does anyone have info (costs, types, where) in the US? 73, Harry, W3IIT hbrown@resd.vf.ge.com ------------------------------ Date: Thu, 8 Sep 1994 20:31:38 GMT From: agate!howland.reston.ans.net!europa.eng.gtefsd.com!newsxfer.itd.umich.edu!isclient.merit.edu!msuinfo!netnews.upenn.edu!news.drexel.edu!news.ge.com!knight.vf.ge.com!nadir!hbrown@ames.arpa Subject: EME amp To: ham-homebrew@ucsd.edu I've heard that Russian tubes are available. Does anyone have info (costs, types, where) in the US? 73, Harry, W3IIT hbrown@resd.vf.ge.com ------------------------------ Date: 9 Sep 94 09:46:59 CDT From: timbuk.cray.com!ned.cray.com!cbetz@uunet.uu.net Subject: EME amp To: ham-homebrew@ucsd.edu In article , laplante@rsvl.unisys.com (Bryan LaPlante) writes: > What are people using for power amplification on EME? I'm looking at 2m or > 432, and trying to keep the costs down somewhat. How much power are you using, > and what is your amp... homebuilt, surplus, used....? If you are going to use a reasonably sized antenna system, then a very economical amp would be a pair of 4CX250s. These tubes are very common on the surplus market, and usually at reasonable prices ($25-40, maybe less). The sockets for these tubes are also fairly inexpensive. There have been numerous articles written on amps for both 2m & 432 that use a pair of these tubes. 10 watts of drive should get you about 600 - 800 watts output. The disadvantage of using tetrodes is the fact that you have to provide an additional power supply for the screen. I have been running 2m EME for about a year. I'm running a pair of 4CX300A's which deleivers about 800 watts output. It is a hamebrew amp that I bought at a hamfest. These tubes work fine on 2m, but they are a lot harder to find than the '250s, and generally the sockets are more expensive (the tubes have a bayonet style base rather than pins, so they require special sockets). My antenna system is 4 x 10 element yagis (K5GL design). It's actually a fairly small system for EME, but it works reasonably well. I have made 11 QSOs with it, including several other 4 yagi stations, plus I've heard quite a few stations that I didn't complete QSOs with. I have, at times, been able to hear my own echos with it as well. Charlie Betz N0AKC ------------------------------ Date: 9 Sep 1994 11:33:03 -0400 From: ihnp4.ucsd.edu!pacbell.com!sgiblab!swrinde!gatech!swiss.ans.net!newstf01.cr1.aol.com!search01.news.aol.com!not-for-mail@network.ucsd.edu Subject: H.P. Digital Panbel Meters To: ham-homebrew@ucsd.edu Can anyone help me with documentation for H.P. Model 3431A Digital Panel meters? I have acquired two of them that I want to use in my 4-1000A Amplifier Project but I don't have pinout numbers or any other info. They are AC operated and look to be 3 1/2 digits. Anyone help on this one? 73 from Russ WA6CWV, Boise ------------------------------ Date: 9 Sep 1994 18:21:01 -0400 From: newstf01.cr1.aol.com!search01.news.aol.com!not-for-mail@uunet.uu.net Subject: H.P. Digital Panbel Meters To: ham-homebrew@ucsd.edu Thanks for the responses to this inquiry. I have what I need !!! Russ Ellsworth WA6CWV ------------------------------ Date: Thu, 8 Sep 1994 17:25:00 +0000 From: ucsnews!newshub.sdsu.edu!nic-nac.CSU.net!charnel.ecst.csuchico.edu!yeshua.marcam.com!insosf1.infonet.net!news.i-link.com!news.sprintlink.net!demon!microvst.demon.co.uk!tgold@@ihnp4.ucsd.edu Subject: Heeeeeeeeeeeelp! To: ham-homebrew@ucsd.edu In article <34kebn$1bj@anemone.saclay.cea.fr> sol@soleil.serma.cea.fr "Michel Soldevila - LENR" writes: > > Hi everybody > > My coax relays are 26 volts models. A long time ago, I saw a circuit able to > trigger > such relays from a 12 volt source. The only thing I remember is that it was a > kind > of voltage doubler who supply the relay with 2x12 volt during a short time, and > then > supply it with 12v. > > Does anybody knows this circuit ? > > Thanks a lot > > 73 de F1GOC K > The trick is to use both your 12v supply plus 12v from a capacitor to push the relay over and then hope that 12v is sufficient to hold it over. No guarantee that only 12v will apply enough contact pressure! You will need a 12v DPDT relay and a 330-470 mFd @ 25 volt capacitor. Also put rectifier diodes across both your 26v and the added 12v relays to kill the spikes plus one more to feed the capacitor. I would guess that you can figure it out. Regret I can't draw a schematic on a keyboard. By the way you can get a very neat complete kit of parts and PC board from Down East Microwave in Maine, tel 207-948-3741 fax 207-948-5157. Costs $10 for their model DEM RVD-1. -- Anthony R. Gold, G3SKR and AA2PM ------------------------------ Date: Thu, 8 Sep 1994 17:15:08 GMT From: agate!howland.reston.ans.net!europa.eng.gtefsd.com!newsxfer.itd.umich.edu!news1.oakland.edu!rcsuna.gmr.com!kocrsv01!c22jrb@ames.arpa Subject: Heeeeeeeeeeeelp! To: ham-homebrew@ucsd.edu In article <1994Sep8.170922.17814@kocrsv01.delcoelect.com>, c22jrb@kocrsv01.delcoelect.com (Jim Buchanan) writes: > > In article <34kebn$1bj@anemone.saclay.cea.fr>, sol@soleil.serma.cea.fr (Michel Soldevila - LENR) writes: > > -- > Jim Buchanan N9SDV > c22jrb@kopt0017.delcoelect.com "Catch 22" > c22jrb@delphi.com > '73 BMW R75/5 "Frau Bluecher" > -- > Jim Buchanan > c22jrb@kopt0017.delcoelect.com "Catch 22" > c22jrb@delphi.com > '73 BMW R75/5 "Frau Bluecher" Wow, I've never (to my knowledge...) double sig'd before! Good work Jim! -- Jim Buchanan c22jrb@kopt0017.delcoelect.com "Catch 22" c22jrb@delphi.com '73 BMW R75/5 "Frau Bluecher" ------------------------------ Date: Thu, 8 Sep 1994 17:09:22 GMT From: agate!howland.reston.ans.net!gatech!newsxfer.itd.umich.edu!news1.oakland.edu!rcsuna.gmr.com!kocrsv01!c22jrb@ames.arpa Subject: Heeeeeeeeeeeelp! To: ham-homebrew@ucsd.edu In article <34kebn$1bj@anemone.saclay.cea.fr>, sol@soleil.serma.cea.fr (Michel Soldevila - LENR) writes: > > Hi everybody > > My coax relays are 26 volts models. A long time ago, I saw a circuit able to trigger > such relays from a 12 volt source. The only thing I remember is that it was a kind > of voltage doubler who supply the relay with 2x12 volt during a short time, and then > supply it with 12v. > > Does anybody knows this circuit ? > > Thanks a lot > > 73 de F1GOC K I remember seeing that too. I don't remember the exact circuit, but here is my best guess. +12 V -----------.---------- | | Q1 | \ R1 |/ / R3 signal in --/\/-.-| \ | |\ D1 | \ >-.--->|---. R2 / | | \ .---||---.--- | | C1 + | | | \ | >|| | /R4 V >|| | \ D2 - >|| K1 | | | | ground ------.-----.--------.--- C1 charges through R3 and and R4 when Q1 is off. When Q1 is switched on, it applies 12V to the low side of C1. The voltage on C1 adds to this 12V and you get 24V across the relay. D1 allows 12 (well, 12 - 0.6) volts to be applied to K1 after C1 has discharged. D2 shunts any inductive kickback back into the coil. If K1 must open rapidly, you might want to substitute an RC snubber circuit. I have not tried this circuit, but it looks likely. Does anyone remember the original circuit? Is it simpler than this? -- Jim Buchanan N9SDV c22jrb@kopt0017.delcoelect.com "Catch 22" c22jrb@delphi.com '73 BMW R75/5 "Frau Bluecher" -- Jim Buchanan c22jrb@kopt0017.delcoelect.com "Catch 22" c22jrb@delphi.com '73 BMW R75/5 "Frau Bluecher" ------------------------------ Date: Fri, 09 Sep 1994 12:57:30 -0400 From: ihnp4.ucsd.edu!agate!howland.reston.ans.net!sol.ctr.columbia.edu!news.msfc.nasa.gov!niven.ksc.nasa.gov!algol.ksc.nasa.gov!k4dii.ksc.nasa.gov!user@network.ucsd.edu Subject: ICOM 22S mod (repeater switch) To: ham-homebrew@ucsd.edu In article <1994Sep9.032345.4806@toybox.raleigh.nc.us>, n4zbb@toybox.raleigh.nc.us (Ken M. Edwards) wrote: > A friend of mine (without internet access) has a ICOM 22s that has > been mod'ed so that all the repeater pairs btwn 146 - 148 on the > front panel instead of the '1', '2', '3', etc. where the diode matrix > determined the Tx and Rx freq.s and included simplex. The > problem is, now that the mod had been made, the simplex freq.s are > no longer avail., but a four row diode matrix is avail. Ken- If that is the same mod as I have, each switch postion is actually for the lower frequency of the repeater pair. When the left-hand toggle switch is in one postion, the radio transmits and receives on the same frequency. When in the other position, it transmits and receives 600 KHz apart. The right-hand toggle switch determines whether the transmit frequency is offset plus 600, or the receive frequency is offset plus 600. Included among those repeater frequencies, are the simplex frequencies as well. As I recall, the switch has MANY postions, and covers from 146.01 to 147.57, in 30 KHz steps. There was an ultra-miniature toggle switch that could be added, that would change the main switch range by 15 KHz, so that all channels could be accessed. A second ultra-miniature toggle switch could be added to make BOTH transmit and receive frequencies be offset plus 600 from the switch setting. As you suggested, I believe there were one or two "blank" switch postions that might be used for diode-programmed frequencies. 73, Fred, K4DII ------------------------------ Date: 9 Sep 1994 13:58:41 GMT From: ihnp4.ucsd.edu!dog.ee.lbl.gov!agate!library.ucla.edu!csulb.edu!nic-nac.CSU.net!charnel.ecst.csuchico.edu!olivea!koriel!newsworthy.West.Sun.COM!abyss.West.Sun.COM!usenet@network.ucsd.edu Subject: Mitrek 800 Mhz Service Manual/ Info ?? To: ham-homebrew@ucsd.edu In article 4933@toybox.raleigh.nc.us, n4zbb@toybox.raleigh.nc.us (Ken M. Edwards) writes: >I have aquired an 800 Mhz Mitrek rig, and wandered if there is a >service manual or info avail. on this unit. Also, is it even remotely >possible to tune this rig in the 33 cm band ? > >Thanks.. Try calling Motorola National Parts at (800) 422-4210 for manual. A radio as recent as the Mitrek should be no problem for a manual. --- * Dana H. Myers KK6JQ, DoD#: j | Views expressed here are * * (310) 348-6043 | mine and do not necessarily * * Dana.Myers@West.Sun.Com | reflect those of my employer * * "Sir, over there.... is that a man?" * ------------------------------ Date: Thu, 08 Sep 94 15:40:22 GMT From: ihnp4.ucsd.edu!pacbell.com!amdahl!netcomsv!netcomsv!skyld!jangus@network.ucsd.edu Subject: need 100 MHz TTL clock To: ham-homebrew@ucsd.edu In article <34l4ru$icc@bmerha64.bnr.ca> kirkland@bgtys22.bnr.ca writes: > Can anyone tell where I can get a 100 MHz TTL clock (i.e. in > quantities of 1/2). Wouldn't that be a 50 MHz clock then? Amateur: WA6FWI@WA6FWI.#SOCA.CA.USA.NOAM | "You have a flair for adding Internet: jangus@skyld.grendel.com | a fanciful dimension to any US Mail: PO Box 4425 Carson, CA 90749 | story." Phone: 1 (310) 324-6080 | Peking Noodle Co. Hate "Green Card Lottery"? Want to help curb ignorant crossposting on Usenet? E-mail ckeroack@hamp.hampshire.edu for more information, or read news.groups. ------------------------------ Date: 8 SEP 94 18:06:47 EST From: pa.dec.com!nntpd.lkg.dec.com!mtwain.enet.dec.com!klaes@decwrl.dec.com Subject: SETIQuest Magazine - Exobiology To: ham-homebrew@ucsd.edu SETIQuest is a new quarterly print/electronic mail (E-mail) periodical containing news, technical information, and tutorials devoted to bioastronomy and its subset, SETI (Search for Extraterrestrial Intelligence). SETIQuest is published for professionals, serious amateur astronomers, and individuals curious about this fascinating field of observation. SETIQuest fills the need for a specialized astronomical publication devoted exclusively to the on-going search for evidence of life in the Universe. Such evidence could be intentional or inadvertent signals of other civilizations. Such evidence could be found in spectral signatures of biological activity on extrasolar planets or in the interstellar medium. SETIQuest is written and edited for the scientifically literate individual taking part in the progress of our technological civilization, with articles by amateur and professional scientists. SETIQuest includes information about hands-on observational programs that can be carried out by individuals and groups of amateur astronomers at radio and optical wavelengths. SETIQuest is filled with articles covering topics such as: * Tutorials about bioastronomy and SETI * Microwave or optical SETI as practiced by amateurs * "Do-it-yourself" participation in bioastronomy and SETI activities * Book reviews * Regular commentary on issues relevant to SETI and bioastronomy: SETI and the political milieu Philosophical issues regarding the prospects of success and failure in the search SETI as a parable of science versus pseudo science Publications Watch: Summaries of recent scientific/general publications relevant to SETI For your FREE issue of SETIQuest (Volume 1, Number 1), send us your postal address by fax, E-mail, or conventional mail to: SETIQuest Inquiries, Department EX Helmers Publishing 174 Concord Street Peterborough, NH 03458-0874 Telephone: (603) 924-9631 FAX (603) 924-7408 Internet E-mail: SQINQNET@pixelacres.mv.com --------------------------------=|=--------------------------------------- Carl Helmers, President & Editorial Director, Helmers Publishing, Inc. --< Publishers of Sensors, ID Systems and SETIQuest magazines >-- (what else do you do after starting BYTE?) INTERNET: carl@pixelacres.mv.com SNAILMAIL: 174 Concord Street, Peterborough, NH 03458 PHONE: 603-924-9631 -=- FAX: 603-924-7408 ------------------------------ Date: Thu, 8 Sep 94 19:57:25 -0500 From: news.delphi.com!usenet@uunet.uu.net Subject: unusual modulation techniques To: ham-homebrew@ucsd.edu A while back I asked about putting 4 distinct voices on a carrier using both sidebands and both quadrature phases. I was told that it's not possible to use both techniques at the same time. I wonder what you'd get, then , if you suppressed one sideband of a QAM signal. (?) Also, I've noticed that the sidebands of an FM signal seem to contain harmonics of the tone being carried. I wonder if there is some way of processing audio (such as distorting it) that will cause an AM transmitter to transmit FM. I want to know if I can transmit FM with a non-variabkle oscillator producing the carrier. (?) Is this possible? ------------------------------ Date: 9 Sep 1994 14:01:47 GMT From: ihnp4.ucsd.edu!usc!nic-nac.CSU.net!charnel.ecst.csuchico.edu!olivea!koriel!newsworthy.West.Sun.COM!abyss.West.Sun.COM!usenet@network.ucsd.edu Subject: xtal filters To: ham-homebrew@ucsd.edu In article 15967@rogue.com, dshalita@rogue.com (David Shalita) writes: >I also need to build xtal filters for a NE-602 project and this method >looks attractive. Need following filters: > 10.7 mhz 55 khz bandwidth > 10.7 mhz 15 khz bandwidth > >Can I use cheap Microprocessor xtals for this 10.7 mhz task? > >Can I make a xtal filter "as wide as" 55khz or 15khz with this technique? > >How can I determine input and output impedance requirements >for the xtal filters produced by this method? It isn't worth the trouble. A&A parts is always at the TRW swap meet selling 30KHz and 15KHz xtal filters for maybe $7/ea. You can probably do better if you go to a distributor, but there's likely to be a minimum order. The 55KHz wide filter may be a problem, but I bought a couple of 15KHz filters from A&A last year. --- * Dana H. Myers KK6JQ, DoD#: j | Views expressed here are * * (310) 348-6043 | mine and do not necessarily * * Dana.Myers@West.Sun.Com | reflect those of my employer * * "Sir, over there.... is that a man?" * ------------------------------ End of Ham-Homebrew Digest V94 #269 ******************************