Date: Mon, 14 Mar 94 04:30:34 PST 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 #60 To: Ham-Homebrew Ham-Homebrew Digest Mon, 14 Mar 94 Volume 94 : Issue 60 Today's Topics: Best cars for mobile HF/VHF?? Best truck/sport util for HF/VHF? Cubic incher Duplexer design info? home-built crystal filter - it works! HP components Info on James Knights Xtal/oven Looking For Plans/kits..vhf Cw/ssb Qrp Ramsey Hobbykits QAMP. Series Diodes (was Re: Paralleling ...) Two Unknown Chips (2 msgs) TX amp kit? Help. WEFAX converter 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: Sun, 13 Mar 94 16:42:44 GMT From: mnemosyne.cs.du.edu!nyx10!jmaynard@uunet.uu.net Subject: Best cars for mobile HF/VHF?? To: ham-homebrew@ucsd.edu In article <1994Mar11.135613.16379@ke4zv.atl.ga.us>, Gary Coffman wrote: >Look at what the cops are driving. Ford Crown Victorias seem popular >with them, as do Chevy Caprices. There's a brand new '94 Crown Vic with police package sitting in my driveway as I type this, courtesy of the EMS I run with. All I can say is...WOW!!! (Unfortunately, I have to pass it along at the end of my shift...) > Order your's with the same fleet codes >that they use and you'll have a car that works well with radios. I thought mere mortals couldn't buy cars with those fleet codes. -- Jay Maynard, EMT-P, K5ZC, PP-ASEL | Never ascribe to malice that which can jmaynard@oac.hsc.uth.tmc.edu | adequately be explained by stupidity. "The difference between baseball and politics is that, in baseball, if you get caught stealing, you're out!" -- Ed Shanks ------------------------------ Date: 13 Mar 1994 20:10:38 -0500 From: ihnp4.ucsd.edu!usc!howland.reston.ans.net!wupost!udel!news.udel.edu!brahms.udel.edu!not-for-mail@network.ucsd.edu Subject: Best truck/sport util for HF/VHF? To: ham-homebrew@ucsd.edu Thanks for your input on cars etc. so far. I have narrowed my thinking to a small pickup or sport utility such as Bronco, Trooper, etc., probably 86 to 91. I am told that American cars have less solid state devices to go awry due to RF from HF or VHF rigs, that Ford seems to be a good choice, that Japanese vehicles may be more susceptible to RF. Again, besides physical comfort (my back) criteria include lack of problems from car to rig and vice versa, and other normal concerns. All input welcomed. Thanks again. Bob -- Bob Penneys, WN3K Frankford Radio Club Internet: penneys@pecan.cns.udel.edu Work: Ham Radio Outlet (Delaware) (800) 644-4476; fax (302) 322-8808 Mail at home: 12 East Mill Station Drive Newark, DE 19711 USA ------------------------------ Date: 14 Mar 1994 09:29:07 GMT From: ihnp4.ucsd.edu!usc!howland.reston.ans.net!pipex!sunic!ugle.unit.no!stud.unit.no!kenneth@network.ucsd.edu Subject: Cubic incher To: ham-homebrew@ucsd.edu Refering to the cubic incher in the ARRL handbook, chapter 30. In the handbook the data for the inductors are only listed for 80, 40 and 30 m. I plan to build this for 20 meter, does anyone out there know the specifications for the inductors ?? thanks, kenneth, LA7GIA. ------------------------------ Date: Sun, 13 Mar 1994 15:09:59 GMT From: ihnp4.ucsd.edu!swrinde!emory!wa4mei!ke4zv!gary@network.ucsd.edu Subject: Duplexer design info? To: ham-homebrew@ucsd.edu In article <199403122332.PAA14622@ucsd.edu> n7oo@huachuca-emh8.army.mil (Jack Taylor) writes: >In browsing various publications, appears modern VHF/UHF duplexer design is >a product of the black art. I'm in the process of cutting down an old >DB Products band-pass 2M duplexer for 220 MHz. This duplexer has coupling >loops in each cavity. My references don't discuss whether there is an >optimum coupling loop shape factor Vs frequency. Nor is anything >mentioned whether the lengths of the cavity coaxial connecting lengths are >critical. One commercial reference cautions field technicians from modifying >the coaxial harness, stating to do so will cause deteriation of duplexer >performance. > >Whilst the cavities are apart, it would be nice to modify them for band- >reject operation as well. Again, my references are silent on this topic. The harness is an integral part of the duplexer. For a band reject duplexer, the electrical lengths of the cables are integral parts of the tuned system. Altering them will grossly alter the behavior of the system. The cables are *slightly* less critical in a bandpass duplexer, but impedance matching is even more critical, and shielding is crucial. A bandpass cavity has two ports, input and output, a band reject cavity has a single port. It behaves as a tuned stub with the harness forming a part of the stub. The idea is to have a pole zero at the thruline connection. Coupling loops really are a black art. Their shape, size, and position all interact to give the desired degree of insertion loss, impedance match, and passband shape. There are analytical methods of designing them, but most shops seem to rely more on cut and try methods. Gary -- Gary Coffman KE4ZV | You make it, | gatech!wa4mei!ke4zv!gary Destructive Testing Systems | we break it. | uunet!rsiatl!ke4zv!gary 534 Shannon Way | Guaranteed! | emory!kd4nc!ke4zv!gary Lawrenceville, GA 30244 | | ------------------------------ Date: Sun, 13 Mar 1994 19:09:15 GMT From: ihnp4.ucsd.edu!agate!usenet.ins.cwru.edu!nshore!seastar!jjw@network.ucsd.edu Subject: home-built crystal filter - it works! To: ham-homebrew@ucsd.edu Another progress report on crystal filter designing: As I did not have the correct caps for an 8-pole SSB filter, I used some of the extra crystals I'd matched to make a 2200Hz 5-pole Chebychev 0.1db ripple filter. Results were quite good! The design spec was for 2200Hz bw, and the result was 2240Hz wide. It drops like a rock on both sides. Is 200 ohms in and out, so I matched it with a 4:1 transformer on the input and a 200 ohm resistor on the end. I have not yet measured insertion loss, and the ripple looks a little bit higher than 0.1db (like maybe 0.5db) using stock value capacitors. I did no tuning at all, just used the closest stock value caps I had, and it works well. The program I wrote calculates not only the shunt caps, but the series caps needed to re-resonate the crystals. These caps are the important ones if you want the shape to be correct. Calculating these by hand is a bit of a bear, but with a computer and BASIC it's pretty easy. Now to prettify the program and the output, get some more caps and sling more solder... 73 de N9JZW -- While (its_not_working()) John Welch, N9JZW mess_with_it(); jjw@seastar.org ------------------------------ Date: 14 Mar 1994 07:26:59 GMT From: olivea!flash!robertov@decwrl.dec.com Subject: HP components To: ham-homebrew@ucsd.edu >Is there anybody that knows which ,if any,74xxxx or other equivalent are >hp components 1820-0092, 1820-0090, 1820-0093, 1820-0119 or >have a list in general for hp to commercial equivalent >sorry if this is a ricorrent question . >Thanks to anybody that will help me. >Please email me directly. Thank to everybody that gave me help in solving this problem. if somebody have the same problem please let me know I will send to him the answer. Again thanks to all. Sincerly Roberto VALFREDINI ------------------------------ Date: 14 Mar 1994 04:49:21 GMT From: ihnp4.ucsd.edu!swrinde!cs.utexas.edu!geraldo.cc.utexas.edu!calvin.ph.utexas.edu!bsn@network.ucsd.edu Subject: Info on James Knights Xtal/oven To: ham-homebrew@ucsd.edu I am looking for information on a crystal/oven manufactured by James Knights Company. It is a 1 MHz rock mounted in an oven which operates at 55 C. The model number is JK5T.The heater runs on 6.3 volts and the volts and the unit plugs into a 5 pin socket. In the best of all worlds, I'd like to know the pin-out, the xtal cut and whether the xtal was designed for series or parallel operation. In any case, does anyone know if the James Knights Co. is still in business? They were located in Sandwich IL when the crystal I have was manufactured. Tne es 73, Barry W5KH ------------------------------ Date: 14 Mar 94 01:43:00 -0500 From: blkcat!1-109-239-0!Timothy.Cadigan@uunet.uu.net Subject: Looking For Plans/kits..vhf Cw/ssb Qrp To: ham-homebrew@ucsd.edu Harry, let me know if you get any bites on your message, I would love to see some qrp stuff for 6 meters! Thanks and good hunting. Also I have found a source for the Motorola FM transmitter chip - nice little thing. thanks again, 73 Tim Cadigan, wc1f Cadigan@Guvax.edu ------------------------------ Date: Sun, 13 Mar 1994 17:12:01 GMT From: ihnp4.ucsd.edu!agate!howland.reston.ans.net!newsserver.jvnc.net!raffles.technet.sg!ntuix!ntuvax.ntu.ac.sg!asirene@network.ucsd.edu Subject: Ramsey Hobbykits QAMP. To: ham-homebrew@ucsd.edu Hi, Has anyone here built the Ramsey Hobbykits' QAMP Tx amplifier with the T-R reply? Any comments? What is the size of this thing and how well does it perform? Tks. 73, Daniel ------------------------------ Date: 11 Mar 94 01:42:42 GMT From: ihnp4.ucsd.edu!munnari.oz.au!yoyo.aarnet.edu.au!news.adelaide.edu.au!news.cs.su.oz.au!metro!grivel!metz.une.edu.au!smattila@network.ucsd.edu Subject: Series Diodes (was Re: Paralleling ...) To: ham-homebrew@ucsd.edu There one more good reason to put a capacitor parallel with a power rectifier diode. Carrier lifetime in typical diode happens to cause fair amount of RF noise in the 1 - 15 MHz band. The noise is very sharp mains frequency pulses. About 1 nF ceramic capacitor parallel with each diode with very short leads takes most of this noise out. The curious thing is, that capacitors before and after bridge rectifier are not effective. Very few books (maybe Rohde's) deal with this phenonema, but I have read about it and made several experiments with various silicon rectifiers. Good old selenium rectifiers are free from this kind of noise. Sakari Mattila smattila@metz.une.edu.au VK2XIN, OH2AZG (Cis: 71307,1525) P.O.Box u13 tel. +61 67 733752 -------------------------------- Armidale NSW 2351 --------------------------- ------------------- ------------------------------ Date: Sun, 13 Mar 1994 05:47:43 GMT From: ihnp4.ucsd.edu!library.ucla.edu!europa.eng.gtefsd.com!howland.reston.ans.net!usenet.ins.cwru.edu!news.ysu.edu!malgudi.oar.net!witch!ted!mjsilva@network.ucsd.edu Subject: Two Unknown Chips To: ham-homebrew@ucsd.edu Hi, I'd like to get a little info on two chips I've run across. One is an NEC B571C, 8 pin DIP (so I know it's not the Signetics compandor). I think it's a prescaler for a PLL. The other is a (Plessey?) PSSR SL560C, 8 pin DIP, which may be an IF amp. I'm hoping to get enough of a description of these to decide if they might be fun to play with. Thanks for any info. 73, Mike, KK6GM ------------------------------ Date: Mon, 14 Mar 1994 09:00:17 GMT From: netcomsv!netcom.com!tgm@decwrl.dec.com Subject: Two Unknown Chips To: ham-homebrew@ucsd.edu Michael Silva (mjsilva@ted.win.NET) wrote: : I'd like to get a little info on two chips I've run across. One is an : NEC B571C, 8 pin DIP (so I know it's not the Signetics compandor). I : think it's a prescaler for a PLL. The other is a (Plessey?) PSSR : SL560C, 8 pin DIP, which may be an IF amp. I'm hoping to get enough : of a description of these to decide if they might be fun to play with. : Thanks for any info. I can help a little on the NEC device. The UPB571C is a dual modulus pre-scaler rated up to 500 MHz. It offers the following ratios: divide by 16, divide by 17 divide by 32, divide by 33 divide by 64, divide by 65 Input sensitivity is 400 mV,p-p and output amplitude is 1.2 V,p-p. Supply voltage is 4.5 to 5.5 volts at 11 mA. I don't have info on the pin-out. I think it is manufactured by a division of NEC known as California Eastern Laboratories. Here are some phone numbers: (408) 988-3500 (408) 988-7846 (213) 645-0985 73, Thomas KI4N ------------------------------ Date: Sun, 13 Mar 1994 15:09:43 GMT From: ihnp4.ucsd.edu!agate!howland.reston.ans.net!newsserver.jvnc.net!raffles.technet.sg!ntuix!ntuvax.ntu.ac.sg!asirene@network.ucsd.edu Subject: TX amp kit? Help. To: ham-homebrew@ucsd.edu Hi, I need a reccomendation for a TX amp of about 20-30 watts output on 20 meters from about 4 watts input, kitform, small sized so I can put it in the same case as my QRP xcvr and with built in T-R switching. Price must not be too expensive. Any ideas? 73, Daniel ------------------------------ Date: 11 Mar 94 01:45:46 GMT From: ihnp4.ucsd.edu!munnari.oz.au!yoyo.aarnet.edu.au!news.adelaide.edu.au!news.cs.su.oz.au!metro!grivel!metz.une.edu.au!smattila@network.ucsd.edu Subject: WEFAX converter To: ham-homebrew@ucsd.edu This comment is in fact a reply to Ron's question, but my mail does not reach him. -------------------------------------------------------------------------- To: us240099@emi.3m.com.dnet Subject: Re: S-Band converter design Newsgroups: rec.radio.amateur.homebrew In-Reply-To: <2klf26$olr@dawn.mmm.com> Organization: University of New England, Armidale, Australia Ron, There are WEFAX converters available from UKW Berichte in Germany. These are very good ones, but pretty expensive. My friend in Finland has one and is satified with it. I have address and some more data at home. Also plans and PCB patterns for some WEFAX converters were published in the Wireless World about 15 years ago. These are still usefull, you only add a modern pre-amplifier. Timestep Limited in U.K. also sells 1.7 GHz WEFAX converters. The output of WEFAX systems is around 137 MHz, you must change some crystals and retune output circuits. Sakari Mattila smattila@metz.une.edu.au VK2XIN, OH2AZG (Cis: 71307,1525) P.O.Box u13 tel. +61 67 733752 -------------------------------- Armidale NSW 2351 --------------------------- ------------------- ------------------------------ Date: Sun, 13 Mar 1994 14:55:42 GMT From: ihnp4.ucsd.edu!swrinde!emory!wa4mei!ke4zv!gary@network.ucsd.edu To: ham-homebrew@ucsd.edu References <1994Mar11.074413.1@csusys.ctstateu.edu>, <1994Mar11.143900.16768@ke4zv.atl.ga.us>, <2ltfqa$31f@winfree.gag.com> Reply-To : gary@ke4zv.atl.ga.us (Gary Coffman) Subject : Re: Looking for plans/kits..VHF CW/SSB QRP In article <2ltfqa$31f@winfree.gag.com> bdale@gag.com (Bdale Garbee) writes: >Gary Coffman (gary@ke4zv.atl.ga.us) wrote: >: Look at the two part feature in recent QSTs describing Rick Campbell's >: SSB rig. It will work on any frequency up to 70 cm. > >I sent an SASE asking for more info to the supplied address a couple of >months ago, but have heard nothing back... was I unlucky? Time to try again, >I suppose. I'm afraid that appears rather typical of Rick. He does good designs, but he services reader response only when he feels like it, which appears to not be often. I had similar problems getting him to fullfill on the 902 MHz transverter kit. I eventually got it, but response time was slightly over one year. (!) I advise getting the board templates from the ARRL and proceeding on your own. (His designs really do tend to be foolproof, it's worth the effort. The slow response I suffered may not be typical, others I know have gotten much quicker service. I've built two different transverters of his design. Both worked first time without any fooling around. I've no doubt the transceivers will work as well. I'm intending to hunt him down at Dayton and deal face to face for a couple of them.) Gary -- Gary Coffman KE4ZV | You make it, | gatech!wa4mei!ke4zv!gary Destructive Testing Systems | we break it. | uunet!rsiatl!ke4zv!gary 534 Shannon Way | Guaranteed! | emory!kd4nc!ke4zv!gary Lawrenceville, GA 30244 | | ------------------------------ End of Ham-Homebrew Digest V94 #60 ****************************** ******************************