Date: Sun, 6 Nov 94 04:30:30 PST From: Ham-Homebrew Mailing List and Newsgroup Errors-To: Ham-Homebrew-Errors@UCSD.Edu Reply-To: Ham-Homebrew@UCSD.Edu Precedence: List Subject: Ham-Homebrew Digest V94 #327 To: Ham-Homebrew Ham-Homebrew Digest Sun, 6 Nov 94 Volume 94 : Issue 327 Today's Topics: Communications Quarterly Hi-Z earphones Local TV Jammer Need Info.Memory Batt Backup PCB Board from laser print?? RF Switching without relays ? selecting IF Sherwood (Drake mods) still available? SW converter help? Where can I find a grid dip meter? 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: Sat, 5 Nov 1994 12:36:32 GMT From: oddjob@cix.compulink.co.uk ("Stephen Walters") Subject: Communications Quarterly Do you have their FAX number or better still, their E-mail address? oddjob@cix.compulink.co.uk ------------------------------ Date: 6 Nov 94 04:02:18 GMT From: gull@grex.cyberspace.ORG (David Brodbeck) Subject: Hi-Z earphones >Does anyone know of a good source for inexpensive high impedance earphones? >I need about 20 of them for the radio club at the local elementary school. >I'm going to have them build one of these radios as a first project. A crystal earphone will work quite well, if you can find one. _ _ __ _ _ _| | | | David Brodbeck Alma, MI / _` | | | | | | | Amateur Packet(AX.25): N8SRE@wb4vva.#nemi.mi.usa.na | (_| | |_| | | | +------------------------------------------------------ \__, |\__,_|_|_| @ grex.cyberspace.org |___/ ------------------------------ Date: 5 Nov 1994 13:37:32 GMT From: moritz@ipers1.e-technik.uni-stuttgart.de () Subject: Local TV Jammer >Anyone have any ideas on how to build a jammer (or modify existing equipment) Wrong Newsgroup, try rec.radio.pirate ------------------------------ Date: 5 Nov 1994 09:29:35 -0800 From: teixeira@ccnet.com (TEIXEIRA) Subject: Need Info.Memory Batt Backup I have a ICOM IC25-A that I use mainly in the shack on a power supply. When I turn off the power supply, the memories go away. Does anyone have any Ideas on adding a battery backup just to support the memories? I was thinking of adding a nicad. Tnx-Don Teixeira N6FNL Fremont,CA ------------------------------ Date: Sun, 6 Nov 1994 02:06:35 GMT From: mzenier@netcom.com (Mark Zenier) Subject: PCB Board from laser print?? Sean Norris (snorris@harp.aix.calpoly.edu) wrote: : I'm working on a project that requires me to make a PC board and I want : it to be as hassle free as possible. I have seen many ads about some : special paper which you can print with a laser printer, iron it onto the : PC board, peel it off and then etch. Has anyone used this technique? If : so, it it reliable? My project is all surface mount and at very high : frequencies so the traces must be small and sharp. This was the subject of a posting in sci.electronics last week. The subject was "Re: Press n Peel". This same information is on the World Wide Web at http://alpha.med.pitt.edu:9000 under the "... Sci.electronics Faq..." item, under the Questions and Answers, in "Where can I get supplies for home PCB manufacture" Thanks to Filip G. Mark Zenier mzenier@netcom.com mzenier@eskimo.com ------------------------------ Date: 5 Nov 1994 17:26:19 GMT From: nick@vlsi.polymtl.ca (Nick Ciarallo) Subject: RF Switching without relays ? In article <4NOV199422283505@vax2.concordia.ca> drobert@vax2.concordia.ca (Denis Robert, ve2ilf) writes: > I'm looking for schematic(s) of general purpose RF TX/RX switching >circuits using diodes. I'd like the switching to be powered by the RF signal >feeding it. I've seen some bits and pieces of this principle but never a >complete 'generic' schematic that one could use to add to a setup or modify >equipment. You have to be more specific. How much power? What frequency? How much isolation? The circuit will not be "powered" by the RF signal. If you could show me how to do that, it would make PIN diode switches alot easier to design. Basically, what you're talking about it a PIN diode switch. The PIN diodes are arranged in (usually) in a series/shunt configuration between the source (the transmitter) and the load (the antenna) and controlled by a DC voltage that turns the diodes on or off. When you provide more info, I'll post a PIN diode RF switch. Nick -- *************************************************************************** * Nick Ciarallo * * SR Telecom Inc. telephone: 514-335-2429 ex: 438 * * Microwave Group facsimile: 514-334-7783 * * 8150 Trans Canada Hwy internet : nick@vlsi.polymtl.ca * * St. Laurent, Quebec hamradio : ve2hot@ve2fkb.pq.can.na * * Canada H4S-1M5 * *************************************************************************** * Accept no substitutes, *REAL* ham radio lives on 220 MHz! * *************************************************************************** ------------------------------ Date: Fri, 4 Nov 1994 09:51:01 UNDEFINED From: mikael.landing@teknikum.uu.se Subject: selecting IF Does anyone know about a computer program that can calculate and pointout spurious responses when using a specified IF-freq and RF-freq in heterodyning?? Micke ------------------------------ Date: Fri, 4 Nov 1994 23:42:04 GMT From: mbutts@netcom.com (Mike Butts) Subject: Sherwood (Drake mods) still available? I'd like to upgrade my Drake C-line with some of the "Sherwood mods", like the audio amp and mixers. Is Sherwood still in business? If so, please drop me a line or post with the address and/or phone. Thanks and 73! --KC7IT -- Mike Butts, Portland, Oregon mbutts@netcom.com ------------------------------ Date: 6 Nov 94 04:17:37 GMT From: gull@grex.cyberspace.ORG (David Brodbeck) Subject: SW converter help? This post is going to be rather long, but I'll try to keep it as short as possible. I'm trying to build a SW converter (SW -> AM broadcast band) from information I found on a local BBS. I'm told this circuit originally came from the October 1989 Popular Electronics magazine. Unfortunately, on the schematic I have C2 (33 pF) is missing. If anyone can tell me where C2 is supposed to go I'd appreciate it, as I'd really like to get the sucker to work. Here's the schematic and parts list: C1 Optional capacitor. Try 150pF with 5 Mhz crystal, or 47pF with 8 Mhz If using crystal >= 10 Mhz omit this capacitor. Omit this capacitor if reception is stronger without it. C2 33 pF C3,C5 220 pF C4 .047 uF D1 Zener diode, either 5.1v or 6.2v (2N4691 or equivalent) R1 1K, 1/4 watt resistor U1 NE602AN Frequency Converter IC T1 10.7 Mhz miniature IF transformer (green plastic screw) XTAL 5 Mhz or 8 Mhz crystal, or other values (see text file XTAL.TXT) One for each band you like to listen to Schematic ========= +----------+--------+----+--/\/\/\-> +12v | ----- | | R1 ---C3 +---+ xtal | | --- +---+ | | | ----- | | J2 (to car radio antenna jack) | | | | +--+ C5 +--+----------+--------++ | | o--------||-------------------+ 7 6 8| | +--+ |5 | | /// gnd | U1 | | | | | J1 (ant.) +---------+ | NE602 | | -+ D1 +--+ | 3+-----+----+1 | +----|<--------+ | o--------+1 | | | Frequency | | +- | +--+ | T1 4+-nc ---C1*| Converter | | | | | | --- | | | | +--------+2 | | | | --- | | | 5+----------+2 | --- C4 | | +---------+ | 3 | | | | +------------+----------+ | | | | | | | | | | +------------------------------------------+--------------+--------------+ /// gnd _ _ __ _ _ _| | | | David Brodbeck Alma, MI / _` | | | | | | | Amateur Packet(AX.25): N8SRE@wb4vva.#nemi.mi.usa.na | (_| | |_| | | | +------------------------------------------------------ \__, |\__,_|_|_| @ grex.cyberspace.org |___/ ------------------------------ Date: 5 Nov 1994 01:18:20 GMT From: tblairm@tu216.tus.ssi1.com (Mark Blair) Subject: Where can I find a grid dip meter? In article <39apma$p3h@cambridge.village.com>, Al Richer wrote: >Can anyone tell me where I can purchase one of hese devices, or better yet, >can someone point me toward a set of plans for same? I would prefer to build >it myself, being the cheap swine that I am........ I think the ARRL Handbook for Radio Amateurs has plans for one, or at least it did back in 1987 when mine was printed. Check out teh nearest ham radio dealer. I've seen that book in generic electronics stores, too. Make sure that the current issue still has grid dip meter plans before you buy it, though. Also, find out if you have any ham swap meets near you; they're often good places to get good deals on old equipment. Like the Racal-Dana 9008 deviation meter that I got for $100, which a certain large surplus dealer in Texas still sells for $995.... (The repair manuals cost me $85 from Racal-Dana, though). -- Mark J. Blair KE6MYK Design Engineer Silicon Systems, Inc. mark.blair@tus.ssi1.com (714) 573-6709 ------------------------------ End of Ham-Homebrew Digest V94 #327 ******************************