Date: Tue, 28 Jun 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 #176 To: Ham-Homebrew Ham-Homebrew Digest Tue, 28 Jun 94 Volume 94 : Issue 176 Today's Topics: Adhesive for lawn mower resistor GPS group purchase shutdown need info on Helical filter design PADS and single-point grounds Realistic (RS) scanner mods 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: 27 Jun 1994 22:32:32 GMT From: ihnp4.ucsd.edu!usc!howland.reston.ans.net!spool.mu.edu!news.clark.edu!netnews.nwnet.net!news.u.washington.edu!roger@network.ucsd.edu Subject: Adhesive for lawn mower resistor To: ham-homebrew@ucsd.edu (A thousand apologies if this post is grossly off-charter for this newsgroup, but this group is the best I could find for this question.) I have an old Black and Decker electric lawn mower that I recently repaired. It's all up and running, except that there is a large (5 ohm, 20 watt, I believe) block-shaped resistor that I need to re-attach to the side of the motor housing. It was originally attached with an off-white, rubbery adhesive. This adhesive isn't silicone or RTV. From my former life as an electronics technician (MANY years ago), I vaguely remember something called (I think) potting compound that was used for this purpose. As I recall, this stuff not only had adhesive properties but also could help act as a heat sink. (Note that I'm NOT talking about the greasy, white heat sink stuff you use when mounting such things as power transistors.) So, if you have any idea what it is I need to get, or if you can tell me that it's OK to use silicone caulk or RTV as a substitute, please let me know. Much thanks in advance. -- Roger Fulton roger@wrq.com ------------------------------ Date: 27 Jun 1994 17:26:24 GMT From: src.dec.com!crl.dec.com!nntpd.lkg.dec.com!nntpd2.cxo.dec.com!specxn.enet.dec.com!bonomo@decwrl.dec.com Subject: GPS group purchase shutdown To: ham-homebrew@ucsd.edu Greetings, all. As I have not achieved critical mass in the number of orders for the Motorola GPS engines, I am shutting down the group purchase. I am on vacation for the next two weeks. If, upon returning, there has not been enough orders received to reach the magic 100 mark, I will be returning the checks to those who have sent them to me, and discontinuing any efforts in this area. As of now, I have orders for about 35 units. For those of you interested, that's about $13,000 sitting on my desk. Thanks for your time, efforts and wonderful interest in this matter. Regards, Tom Bonomo ------------------------------ Date: Mon, 27 Jun 1994 16:26:00 GMT From: library.ucla.edu!europa.eng.gtefsd.com!newsxfer.itd.umich.edu!nntp.cs.ubc.ca!torn!news.unb.ca!coranto.ucs.mun.ca!nstn.ns.ca!newsflash.concordia.ca!pavo.concordia.ca!@@ihnp4.ucsd.edu Subject: need info on Helical filter design To: ham-homebrew@ucsd.edu In article <2uf4m6$7h5@lsi.lsil.com>, achien@lsil.com writes... >I am looking for information on how to design a "Helical filter" . Any books, papers or design equations available for this kind of filters? I know "TOKO coil" make this kind of filters but I need to custom design my own filter. >--- >Arthur Chien Info on this type of filter is somewhat hard to find but I have spent *more* than a little time searching so I think I can save you some time. Got a pen ? As usual, the ARRL handbook touches on the subject. Handbook of Filter Synthesis, A.I. Zverev ISBN 0-471-98680-1 Reference Data for Radio Engineers, Howard Sams (pre-seventh edition) Filters with Helical and Folded Helical Resonators, Peter Vismueller ISBN 0-89006-244-7. There are a few more but these are the most common and should get you started. BTW, the Zverev is out of print and is hard to find except in the reference section of an engineering library (the copy at my library has been stolen by some unscroupulous filter engineer). The Vismueller book *JUST* went out of print a couple of weeks ago; at that time, the publishers had 2 copies left which go for a hefty price (something like $70 CDN -Yeowch!). -Good luck Mark, VE2HVW ------------------------------ Date: Mon, 27 Jun 1994 12:09:50 GMT From: wang!pvr@uunet.uu.net Subject: PADS and single-point grounds To: ham-homebrew@ucsd.edu haymoree@newt.ee.byu.edu (Ed Haymore) writes: $>I've been trying to get the shareware PADS to bring all grounds in my $>circuit into a single point, without success. I don't seem to have any $>control over which pins have the physical connections -- I can connect $>all grounds to a single point on the schematic, but when it's imported $>into PADS-PCB, that information is lost and PADS re-connects the pins in $>a daisy-chain format. You will have to hand route your ground traces. The trick is that you must run one ground trace over top of other ground traces. The copper will be correct but your layout under PADS will be more complex. What you must do is to first route the trace from the circuit ground point to the common ground point. Next, continue from the common ground point to the point that PADS connected the ground. This will complete the routing and make PADS happy. The trace should be routed on top of the previous trace going to that circuit ground. How you draw the circuit has no bearing on how the netlist is created. The netlist is only electrically correct. It is only the netlist that controls how the routes are run. Pete. -- -->>>>>>>>>> Peter Reilley ..... pvr@wiis.wang.com ..... KA1LAT <<<<<<<<<<<-- BEAV, the best binary file editor w/src. For info finger pvr@das.wang.com Well, that about says it. ------------------------------ Date: 27 Jun 94 17:17:00 GMT From: news-mail-gateway@ucsd.edu Subject: Realistic (RS) scanner mods To: ham-homebrew@ucsd.edu ihnp4.ucsd.edu!agate!spool.mu.edu!news.clark.edu!netnews.nwnet.net!ns1.nodak .ed (Larry) writes: >Hi ALL: >I have a Realistic PRO-2023 programmable scanner. I would like to modify >it for operation on 6, 10, 12, ... meters. I think 6 and 10 should be >fairly easy since it's right on the edge, I'm not sure about the rest. >Anyone recommendations would be appreciated. >thanks-- >*************************************************************************** *** >Larry Heiss >University of Arkansas @ Little Rock >Laser Applications Lab >e-mail heiss@ualr.edu >call: KC5CVL >*************************************************************************** *** I'm don't remember what the PRO-2023 was, if it is one of their programmable scanners it is very unlikely that you can mod it to do anything. They are controlled by a microprocessor that has the PLL frequency generator built in. You would have to reprogram the microprocessor to be able to make it scan other bands. The receiver itself would have no problem with 6 meters but 10 might be a little out of its range. If it is one of their (RS) crystal controlled units you should have no problem with the mod, although 10 meters might be a little much to ask for but 6 should be no problem. Kevin Legal stuff: The above opinions are my own and not necessarily those of the staff, faculty, administration, or lab animals (woof!) of The University of Texas Health Science Center at San Antonio. ---------------------------------------------------------------------- Kevin R. Muenzler, WB5RUE The University of Texas Health muenzlerk@uthscsa.edu Science Center at San Antonio, Department of Computing Resources ** There is no such thing as a Monkey-Proof Program! ** ** I can prove it! ** ---------------------------------------------------------------------- ------------------------------ End of Ham-Homebrew Digest V94 #176 ******************************