Date: Sun, 22 May 94 04:30:49 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 #137 To: Ham-Homebrew Ham-Homebrew Digest Sun, 22 May 94 Volume 94 : Issue 137 Today's Topics: Amidon Cores (2 msgs) Digital Delay Circuit Ideas? HELP! Need 'advice' on transmitter construction. (2 msgs) Propagation E-Sporadic What are these chips? (2 msgs) 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: 20 May 1994 16:25:54 GMT From: elroy.jpl.nasa.gov!usc!howland.reston.ans.net!europa.eng.gtefsd.com!newsxfer.itd.umich.edu!zip.eecs.umich.edu!yeshua.marcam.com!news.kei.com!ssd.intel.com!chnews!cmoore@ames.arpa Subject: Amidon Cores To: ham-homebrew@ucsd.edu boylanj@bcvms.bc.edu wrote: : Can anyone help me with an address for Amidon, John Boylan Amidon Associates, Inc., P.O.Box 956, Torrance, CA 90508 Tel. (310)763-5770 FAX (310)763-2250 73, KG7BK, CecilMoore@delphi.com ------------------------------ Date: 21 May 94 23:29:49 GMT From: agate!library.ucla.edu!csulb.edu!nic-nac.CSU.net!charnel.ecst.csuchico.edu!olivea!apple.com!apple.com!not-for-mail@ucbvax.berkeley.edu Subject: Amidon Cores To: ham-homebrew@ucsd.edu boylanj@bcvms.bc.edu writes: >I am looking for an Amidon torroidal core (#FT240-43, ref. ARRL Handbook >27-2, power supply project). Can anyone help me with an address for Amidon, >a distributor for these cores, or a substitute? Thanks in advance. Amidon advertises in QST and Communications Quarterly. They can be reached at Amidon Associates, Inc. P. O. Box 956 Torrance, CA 90508 Phone: 310-763-5770 Fax: 310-763-2250 I have ordered numerous times from them and found them to be very friendly and efficient. Other than being a satisfied customer, and being glad for a convenient place that sells ferrite materials to individuals, I have no connections with them. 73 Kok Chen, AA6TY kchen@apple.com Apple Computer, Inc. ------------------------------ Date: 21 May 94 04:37:52 GMT From: agate!spool.mu.edu!howland.reston.ans.net!gatech!usenet.ufl.edu!gnv.ifas.ufl.edu!climatol@ucbvax.berkeley.edu Subject: Digital Delay Circuit Ideas? To: ham-homebrew@ucsd.edu In article , jra@lawdept.daytonOH.ncr.com (John Ackermann) writes: > I'm designing a clock to be driven by my local frequency standard. My goal is > to be able to set the second mark to better than 1 millisecond (and I hope > eventually much better than that). > > To do this, I need to build a variable delay that I can use to slew the > seconds marker. Actually, I'll need a couple of delays, starting at a higher > frequency for fine adjustment, and finally running at a lower one for course > adjust. Obviously, for stability reasons I want to do this digitally and not > with some sort of analog delay. > > Any suggestions on CMOS devices (probably a presettable counter?) that > would work well here? The larger the count range in a single chip, the > better. > > Thanks... > You don't give enough detail about your circuit to make a definite choice, but I would be extremely inclined to use a low-end microcontroller here. Depending on the device you select, you should easily be able to set up a selectable delay accurate to anywhere from one microsecond to .1 millisecond. For that matter, why not do the whole thing in a microcontroller? -- Bob Johnson, WB4JCM rejo@gnv.ifas.ufl.edu ------------------------------ Date: 20 May 1994 23:35:03 -0400 From: ihnp4.ucsd.edu!agate!howland.reston.ans.net!europa.eng.gtefsd.com!newsxfer.itd.umich.edu!gatech!news.ans.net!newstf01.cr1.aol.com!search01.news.aol.com!not-for-mail@network.ucsd.edu Subject: HELP! Need 'advice' on transmitter construction. To: ham-homebrew@ucsd.edu In article , seymour@netcom.com (Kenneth Seymour) writes: RE: >i just built a 2-transistor, .2 Watt transistor. >I'm looking to build a bigger, more powerful model, and also make >an efficient antenna. Kenneth...Judging from your message, it appears that you are coming from the Pirate Radio group......if so you are posting this message in an Amateur Radio group. We are licensed amateur radio operators and we do not think kindly of unlicensed operations. There is more to building a radio transmitter that just putting the parts together and trying to get something on the air. A poorly built transmitter could transmit on more than the intended frequency at one time and you could unknowingly create interference. If you are interested in becoming a legally licensed ham operator, let me know and I can point you in the right direction. ------------------------------ Date: Fri, 20 May 1994 21:09:35 GMT From: ihnp4.ucsd.edu!news.acns.nwu.edu!math.ohio-state.edu!howland.reston.ans.net!europa.eng.gtefsd.com!library.ucla.edu!csulb.edu!csus.edu!netcom.com!seymour@network.ucsd.edu Subject: HELP! Need 'advice' on transmitter construction. To: ham-homebrew@ucsd.edu In article , Pleasure Death wrote: >Hi, > >i just built a 2-transistor, .2 Watt transistor. >I can get pretty good range with it (approx 250 metres) with a 'bad' >set-up ,ie not covered, poor antenna. > >I'm looking to build a bigger, more powerful model, and also make >an efficient antenna. > >Can anyone give me any information on doing this? >Also can anyone reccomend any TEXTS are transmittor construction, >esp one with circuit diagrams..... > I would recommend the ARRL publication "Circuit Design for the Radio Amateur". It has more discussion of the circuit theory than the ARRL Handbook. It also has the circuit diagrams for some projects. > >Thanks. > >Si. > -- Ken Seymour seymour@ast.saic.com ------------------------------ Date: 20 May 1994 13:31:53 GMT From: agate!howland.reston.ans.net!math.ohio-state.edu!jussieu.fr!univ-lyon1.fr!elendir@ames.arpa Subject: Propagation E-Sporadic To: ham-homebrew@ucsd.edu Salut Daniel, Daniel Rossier (drossier@disuns2.epfl.ch) wrote: : Could anybody tell me if it's possible to tranceive on the 2m band : using the E-sporadic propagation. It seem's to be better with : the SSB mode but I'm not sure that it's not possible to do it with : a FM 2m Handy with 5watts (and perphaps also on 70cm band) ?? Je vois que tu as comme moi une installation QRP. Je ne suis pas sur a 100 %, mais la propag en E-spo est quand meme tres sportive, surtout sur 2 metres. A mon avis, avec un petit portable ca n est guere possible. La plupart des contacts en 2 metres BLU se font en tropo ou en meteor scatter. Les ouvertures en E-spo sont rarissimes. En plus, la BLU etant plus efficace que la FM va evidemment plus loin. Sur UHF, il n y a plus de E-spo, que de la tropo - sauf condition vraiment anormale. Quant a la prevision de la spo, comme son nom l indique, elle est justement imprevisible. Ce sont des paquets ionises plus fortement qui se forment et se disloquent on ne sait pas trop comment. Le mieux est de rester a l ecoute !!! Mais la E-spo, c est grand sur la bande des 6 metres !!!! :-) 73 QRO ! Vincent, F1RCS. ------------------------------ Date: Thu, 19 May 94 03:07:15 -0500 From: yale.edu!noc.near.net!news.delphi.com!usenet@yale.arpa Subject: What are these chips? To: ham-homebrew@ucsd.edu Get an old copy of the "IC Master" published by Hearst Business Publishing for basic information on virtually any IC chip. These books are about $170 new, and are published annually. You should be able to get a five-year-old copy for next to nothing. ------------------------------ Date: 21 May 94 04:29:21 GMT From: agate!howland.reston.ans.net!gatech!usenet.ufl.edu!gnv.ifas.ufl.edu!climatol@ucbvax.berkeley.edu Subject: What are these chips? To: ham-homebrew@ucsd.edu In article <2r5ugl$po8@apple.com>, kchen@apple.com (Kok Chen) writes: > denglet1@iia.org (Tom Dengler) writes: > >>I have about 40 or so old circuit boards with some socketed chips that I >>was wondering what they might be good for. Can anyone can give me a >>brief functional description of these chips? [...] >>[6] TMS - 24 pin - See through window on top >> 2516JL-35 >> MFP8401 > > Sounds like Texas Instruments' version of the 2716 EPROM, 350 ns > access time. 8401 again a date code - 1st week, 1984. Do you see a > TI logo (little map of the Republic of Texas) on it? 16 kilo bits > (no, not bytes -- we are talking about the stone age, remember?) > worth of erasable memory. I don't completely remember now, but there > was something quirky about the 25xx series. Was it that it needed > a +12 volt supply in addition to +5 volt? What was quirky was the TMS2716 : it used different programming voltages than everyone else's 2716. The TMS2516 was TI's version that used the same voltages as everyone else (so I guess its quirk was that it was numbered differently). -- Bob rejo@gnv.ifas.ufl.edu ------------------------------ End of Ham-Homebrew Digest V94 #137 ******************************