Date: Sun, 26 Jun 94 04:30:21 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 #174 To: Ham-Homebrew Ham-Homebrew Digest Sun, 26 Jun 94 Volume 94 : Issue 174 Today's Topics: 49MHz walkie talkies lega Connecting frequency coun need info on Helical filter design PADS and single-point grounds 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, 24 Jun 94 13:18:00 -0600 From: ihnp4.ucsd.edu!library.ucla.edu!agate!iat.holonet.net!sound!richard.dale@network.ucsd.edu Subject: 49MHz walkie talkies lega To: ham-homebrew@ucsd.edu AU>don't want to lose it. Can a 49MHz walkie talkie(runs from a 9v battery) AU>be converted to run on other bands, such as 440, legally? I thouhtabout AU>changing the crystal and antenna to the frequency I want. Please do not Legally, yes. Easily, no. You're looking at moving a cheap piece of equipment almost 400 MHz. That's akin to converting a Radio Shack Flavoradio to pick up TV. Say you spend $20 for a pair of those units. Figure on spending at least another $50-$100 in attempting to convert them over. Then look at Ramsey's catalog -- a five-watt, 12-channel 440 MHz unit for $149.95 (less case). I've heard of people moving those units up to 6 meters with varying degrees of success, though. The best I've heard is some guy who mounted one up on a tower and operated it by remote control with his shack. He had worked six states when I read the article. --- þ DeLuxeý 1.26b #2989 þ Bill Clinton is in Psalms 109:8 ------------------------------ Date: Fri, 24 Jun 94 13:27:00 -0600 From: ihnp4.ucsd.edu!agate!iat.holonet.net!sound!richard.dale@network.ucsd.edu Subject: Connecting frequency coun To: ham-homebrew@ucsd.edu HA>I have an old receiver (tubes, .5-30 MHz) with analog tuning. HA>I also have a frequency counter which I want to connect so HA>as to be more accurate in determining the frequency I am If you know how to get in touch with the International Radio Club of America (IRCA), they had a group of members who did something similar back in the mid 70s. They would get really good accuracy, often to the point of being able to ID a station simply by its frequency. IRCA has a reprint service, and that info should be available. I don't have their address, but it should be in the WRTH. --- þ DeLuxeý 1.26b #2989 þ Bill Clinton is in Psalms 109:8 ------------------------------ Date: 25 Jun 1994 05:16:24 GMT From: ihnp4.ucsd.edu!galaxy.ucr.edu!library.ucla.edu!agate!spool.mu.edu!bloom-beacon.mit.edu!senator-bedfellow.mit.edu!news.mit.edu!monta@network.ucsd.edu Subject: need info on Helical filter design To: ham-homebrew@ucsd.edu achien@lsil.com (Arthur Chien - 4582) 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. VHF/UHF Handbook, by Jessop, has a good description of helical filter design; the ARRL Handbook also has a section on them. Zverev's classic filter design book has a very interesting chapter on resonators of various sorts, including helicals at VHF and HF. I recently ran across a book, whose title escapes me (from Artech House?), specifically about helical filters and how to avoid 3\lambda/4 spurs and other annoyances. The author advocates using a coil with a sense reversal partway along it. Peter Monta monta@image.mit.edu MIT Advanced Television Research Program ------------------------------ Date: 25 Jun 1994 17:57:26 GMT From: ihnp4.ucsd.edu!library.ucla.edu!europa.eng.gtefsd.com!MathWorks.Com!news.kei.com!news.byu.edu!news@network.ucsd.edu Subject: PADS and single-point grounds To: ham-homebrew@ucsd.edu 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. Any suggestions? -- Ed Haymore | AA6EJ ed@byu.edu | Try not. Do. Or do not. There is no try. ------------------------------ End of Ham-Homebrew Digest V94 #174 ******************************