Date: Wed, 2 Feb 94 04:30:32 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 #17 To: Ham-Homebrew Ham-Homebrew Digest Wed, 2 Feb 94 Volume 94 : Issue 17 Today's Topics: Antenna pre-amp design. Help! Build a simple 49 mhz reciever? IC info "042P" IC Info, "042P" Mail-order toroids, RF transistors, Help! Mystery components? Help? PROJECT 14: THE WORLD'S SMALLEST TRANSMITTER VLF/ELF W7ZOI Progressive Receiver 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: 1 Feb 1994 02:21:02 GMT From: koriel!newscast.West.Sun.COM!abyss.West.Sun.COM!sunspot!myers@decwrl.dec.com Subject: Antenna pre-amp design. Help! To: ham-homebrew@ucsd.edu In article 1@ntuvax.ntu.ac.sg, asirene@ntuvax.ntu.ac.sg () writes: >In article <2i68cr$isj@reznor.larc.nasa.gov>, kludge@grissom.larc.nasa.gov (Scott Dorsey) writes: >> In article <1994Jan26.001852.3038@ke4zv.atl.ga.us> gary@ke4zv.atl.ga.us (Gary Coffman) writes: >>> >>>In looking through my collection of ARRL Handbooks, I don't find a >>>HF preamp until I go back to the 1962 edition. They have one using >>>a 6AK5 pentode. This should give you an idea of the apparent lack >>>of need for such circuits with more modern equipment. >> > Gary is probably right but then if you look in the MFJ catalog I >am sure you will find one or two active antennas, which are quite expensive >when you consider the number of components involved. Thus in case of the >lack of a good antenna, active antennas/pre-amps still help. > >> Actually, I recommend this circuit... I built it when I was a kid and >> hung it on the front of a modified Philco table radio and it worked very >> nicely to the point where the rotten selectivity of the radio was a problem. >> The manufacturer probably never expected anyone to tear windings off the >> AM loopstick to move it to 80M. >> --scott > > However, a valved pre-amp was not quite what I had in mind :) I was >thinking more along the lines of the dual-gated mosfets or bi-polar types >for broadband amplification as well as for narrow band. :) OK. so shoot me if this is too simple. Buy an MSA-1104 (this is in the large, easy-to-handle, plastic microwave package). I got some for $3.25/ea last week. This is a 50ohm in/out MMIC with 12-13dB of gain up to the Ghz range. It is capable of over 50mW of output combined with a noise factor of below 3.6 in the HF bands. With DC blocking caps of 1000pF, a 100uH choke and bias resistor for 50mA of bias current, you'll have a no-pain preamp with a pretty good dynamic range. If you feel like working just a little, try using a broad-band grounded gate J310; you can get about the same gain and IP3 but a noise figure below 1dB. Use a small ferrite balun core with a turns ratio of 4:1 (16:1 Z ratio) on the output, use a 220 ohm bias resistor, go to town. I bought a stash of J310s for $.34/ea; the additional components would make the total cost similar to the MSA-1104 circuit, with a lower NF. On HF, a 3.5dB NF is not a big deal. --- * Dana H. Myers KK6JQ, DoD 466 | Views expressed here are * * (310) 348-6043 | mine and do not necessarily * * Dana.Myers@West.Sun.Com | reflect those of my employer * * This Extra supports the abolition of the 13 and 20 WPM tests * ------------------------------ Date: Tue, 1 Feb 1994 07:06:38 GMT From: mentor.cc.purdue.edu!rock-opera.cc.purdue.edu!adkinsg@purdue.edu Subject: Build a simple 49 mhz reciever? To: ham-homebrew@ucsd.edu Hi all! I'm wanting to play with the signals from my cordless phone, and I would like to build a simple FM reciever so I can digitize the signals between the base and handset. The phone is a sony spp-75 with 10 "channels" operating at 49 Mhz (not one of the new fangles 900 mhz jobbies) The phone is pretty smart and won't turn on unless it can "talk" to the base. I have a good scanner (RS pro-2004 ) but my dad has it and won't give it back. :-( So I want to build a simple analog tuner out of perhaps a cheapie FM radio. The only thing I care about is having the ability to digitize the "braaaap" of base/handset communication. I'll only be a foot from the base/handset so reception range isn't critical either. (Altho the computer will be on so I'll have to account for that hash..) Any suggestions?? Thanks! Garry -- ------------------------------------------------------------------------ Garry Adkins adkinsg@symphony.cc.purdue.edu ------------------------------------------------------------------------ USnail: 425-7 South River Rd. GTENet: +1-317-743-8188 ------------------------------ Date: 2 Feb 94 00:47:07 GMT From: news-mail-gateway@ucsd.edu Subject: IC info "042P" To: ham-homebrew@ucsd.edu A friend of mine has a swap meet special that uses an IC marked "042P". The IC seems to take a 46 to 63 mhz input, seems to be a mixer oscillator, and has a 10.7 mhz ouput. He needs to purchase a few more. The vendor is unknown. We would appreciate any leads to where we can purchase this IC and who the vendor might be? Thanks and 73 Dave w6mik ------------------------------ Date: 2 Feb 94 00:58:04 GMT From: news-mail-gateway@ucsd.edu Subject: IC Info, "042P" To: ham-homebrew@ucsd.edu Subject: IC info "042P" Text: A previous message sent had an INCORRECT reply to address..sorry =============================== A friend of mine has a swap meet special that uses an IC marked "042P". The IC seems to take a 46 to 63 mhz input, seems to be a mixer oscillator, and has a 10.7 mhz ouput. He needs to purchase a few more. The vendor is unknown. We would appreciate any leads to where we can purchase this IC and who the vendor might be? Thanks and 73 Dave, w6mik Even a cross referenced replacement is ok. ------------------------------ Date: Mon, 31 Jan 1994 18:04:08 GMT From: ucsnews!sol.ctr.columbia.edu!howland.reston.ans.net!newsserver.jvnc.net!raffles.technet.sg!ntuix!ntuvax.ntu.ac.sg!asirene@network.ucsd.edu Subject: Mail-order toroids, RF transistors, Help! To: ham-homebrew@ucsd.edu Hi, Can some kind hearted HAM help me order some parts from Amidon Associates Inc. I do not have the catalog so I do not know how much to send, how much for shipping, minimum order. This is for sending to Singapore where toroids are non-existent. I am also in need of MRF472 or MRF476. The toroids I am interested in are:- 4 x FT37-43 core 2 x FT50-43 core 2 x FB73-801 ferrite bead 73 de 9V Daniel 4 x T-50-6 core 2 x T-37-6 core Would appreciate any help for ordering these stuffs. Need them fast. I need 2 MRF-472 (or MRF-476 if 472's are not available) and also a 14 mHz fundamental crystal. What is the fastest way I can get hold of these? Tks. 73 de 9V Daniel ------------------------------ Date: 31 Jan 1994 09:03:41 -0800 From: ucsnews!sol.ctr.columbia.edu!howland.reston.ans.net!agate!apple.com!apple.com!not-for-mail@network.ucsd.edu Subject: Mystery components? Help? To: ham-homebrew@ucsd.edu kludge@grissom.larc.nasa.gov (Scott Dorsey) writes: >In article <1994Jan29.213947.1@aurora.alaska.edu> fsrla@aurora.alaska.edu writes: >>The second one was blue and had the following letter, number sequence. >> P >> RN55D >> 3572 >> FJ >>What is this one? > >Two pins on it? Shaped like a disc capacitor? The RN55D looks suspiciously like the designator for a precision metal film resistor. So is the blue colour. Assuming it is an axial device, instead of a disc shaped device as Scott has guessed, I would guess that this is a 35.7 kilo ohm resistor. Don't you have an ohm guesser^H^H^H^H^H^H^H meter handy? 73, Kok Chen, AA6TY kchen@apple.com Apple Computer, Inc. ------------------------------ Date: 1 Feb 94 22:31:02 GMT From: ogicse!news.tek.com!gvgpsa.gvg.tek.com!gold.gvg.tek.com!grovmac.gvg.tek.com!cleveland@network.ucsd.edu Subject: PROJECT 14: THE WORLD'S SMALLEST TRANSMITTER To: ham-homebrew@ucsd.edu Re: PROJECT 14: THE WORLD'S SMALLEST TRANSMITTER Are y'all forgetting the Fireball transmitter? Battery, key, dip relay, xtal oscillator at 29.060, antenna. I think this about as minimalist as anyone could go. Grover WT6P ------------------------------ Date: Mon, 31 Jan 94 09:17:41 CST From: mvb.saic.com!unogate!news.service.uci.edu!usc!howland.reston.ans.net!agate!iat.holonet.net!vulcan!gary@network.ucsd.edu Subject: VLF/ELF To: ham-homebrew@ucsd.edu Hi: I have been looking for some reference material on VLF and have been unable to find any. Can anyone point me to any material on VLF receivers ? I am especially interested in receiving (is it WWVB?) on 60 kHz, but would also be interested in the unlicensed band at (what I think is 1750 meters). I understand that there is an organization called the 'Longwave Club of America'. Does anyone have an address for them ? Thanks Gary Tennyson KO4CY gary@vulcan.com Gary Tennyson gary@vulcan.com ------------------------------ Date: 1 Feb 94 01:14:30 GMT From: auratek!epacyna@uunet.uu.net Subject: W7ZOI Progressive Receiver To: ham-homebrew@ucsd.edu Several weeks back I met someone in the newgroup who was going to build the subject receiver. I have something to send you, but have lost your address. 73 Ed W1AAZ ------------------------------ Date: Tue, 01 Feb 94 08:09:53 GMT From: mvb.saic.com!unogate!news.service.uci.edu!usc!cs.utexas.edu!swrinde!emory!rsiatl!jgd@network.ucsd.edu To: ham-homebrew@ucsd.edu References <1994Jan27.151922.7122@rz.uni-hildesheim.de>, , l Subject : Re: High Voltage Power Supply dtiller@cscsun.rmc.edu (Dave Tiller) writes: >: hmmm, 7kv x 2 amp, about 14kw on the plate....thats one healthy afterburner. >: You should be worried about the coax feed also. >Also worry about soft X-ray emission at 7kV - that kind of voltage with that >amount of current pushing it should generate lots of low energy X-Rays. Let's see. With an iron plate in the tube and 7kv, that should produce X-rays with a peak energy in the 4 KeV range. That should be able to penetrate oh, maybe 3 or 4 inches in air. It certainly wouldn't penetrate the leaded glass envelope. Nor would it penetrate a ceramic/metal tube envelope. A real hazard,huh? (NOT!) High current doesn't equate to high energy. It only increases the intensity. A little knowledge is a dangerous thing. John -- John De Armond, WD4OQC, Marietta, GA jgd@dixie.com Performance Engineering Magazine. "Dr. Kevorkian, you're needed in the Oval Office." ------------------------------ Date: Sat, 29 Jan 1994 01:19:31 +0000 From: library.ucla.edu!europa.eng.gtefsd.com!howland.reston.ans.net!pipex!demon!dis.demon.co.uk!djwhome.demon.co.uk!david@network.ucsd.edu To: ham-homebrew@ucsd.edu References <16fT02SH5bd501@JUTS.ccc.amdahl.com>, , <654f02la5b3Z01@JUTS.ccc.amdahl.com> Subject : Re: IBM-PC Shareware for PCB Photo work easytrax is on all Simtel sites (e.g. oak.oakland.edu) and on the Simtel CDROM. The following is from the May 93 CD (info@cdrom.com). Directory MSDOS/CAD/ Filename Type Length Date Description ============================================== EASYTRAX.ZIP B 471281 930318 Protel's powerful PCB layout, freeware version Other related items in the same directory. GCPVU.ZIP B 320423 911104 Professional quality CAD tool for PCB design PADSLIB.ZIP B 461934 920212 PADS library for PADSPCB.ZIP and PADSLOG.ZIP PADSPCB.ZIP B 988785 920212 PADS PCB (printed circuit board) layout pgm PCB.ZIP B 90057 890325 Small PC board CAD pgm w/'C' src, 286 only PCROUTE2.ZIP B 97546 900413 Computer aided design, printed circuit boards PFWDEM10.ZIP B 948420 920805 Protel PCB for Windows DEMO. Reqs Win 3.0/3.1 QR15R3US.ZIP B 218259 930219 Easy to use PCB & schematic design system QRUSA.ZIP B 116834 920522 QuickRoute: Circuit board / diagram design -- David Woolley, London, England david@djwhome.demon.co.uk ------------------------------ End of Ham-Homebrew Digest V94 #17 ****************************** ******************************