Date: Thu, 2 Dec 93 04:30:42 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 V93 #120 To: Ham-Homebrew Ham-Homebrew Digest Thu, 2 Dec 93 Volume 93 : Issue 120 Today's Topics: sw-radio coils...question. Telephone Interface Circuit ? TMS32010 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: Tue, 30 Nov 1993 18:21:50 GMT From: swrinde!sgiblab!sgigate.sgi.com!olivea!news.bu.edu!att!cbnewsm!jeffj@network.ucsd.edu Subject: sw-radio coils...question. To: ham-homebrew@ucsd.edu In article <2649@arrl.org> zlau@arrl.org (Zack Lau) writes: >In rec.radio.amateur.homebrew, st92ba44@dunx1.ocs.drexel.edu ( antonio gatta) writes: >> I'm not sure if this is the right place to ask but the title seemed >> appropriate (and I couldn't find a faq). Anyhows, I'm working on >> a crystal shortwave radio which requires a t-50-2 toroid core onto >> which the coil is wound. I'm wondering if a straight (bar) ferrite >They are similar in that both are used to increase the inductance of a >coil. However, type 2 iron powder of 10, while ferrite materials usually >have a much higher permeability (though some VHF materials have a similar >permeability). Ferrites typically have higher loss, though I've seen >inductors wound on type 67 material with low loss. Many will have 1 to >2 magnitudes more loss. Ferrites are often less frequency stable. I was wondering about the differences between the various core types. In some applications they call for T-50-2 and others they call for T-50-6. A lot of times it looks like they are using what they have on hand and you could subsitute a T-50-2 for a T-50-6 or vice versa. Is the 2 or the 6 extender more of a indication of the amount of power the toriods can handle? As I am just getting started in doing some of my own homebrewing it would be nice to know that I can use a T-50-2 that I have on hand rather then having to wait for mailorder to show up with a T-50-6. The applications I am working with are VFO's, output filters and matching impedances. Could someone enlighten me on toriods? 73! Jeff -- Jeff Jones AB6MB | Vote out those who voted for the North American jeffj@seeker.mystic.com | Free Trade Agreement! Infolinc BBS 510-778-5929 | ------------------------------ Date: Wed, 1 Dec 1993 09:53:17 GMT From: news.cerf.net!pagesat!netsys!agate!howland.reston.ans.net!ee.und.ac.za!hippo.ru.ac.za!pukrs7.puk.ac.za!pc2.puk.ac.za!itbkl@network.ucsd.edu Subject: Telephone Interface Circuit ? To: ham-homebrew@ucsd.edu Hi. I am looking for examples of circuits that will allow me to interface any audio based equipment (say a PC's soundblaster card or audio from HF rig, etc.) to the telephone line. The circuit should have all the lightning protection, isolation, etc. that is sufficient for the Telco to pass an acceptance test. I have in mind a circuit with the following interfaces : a) connection to telephone line. b) audio out c) audio in. d) ring detect (say 5v out = ring) e) go off-hook (say +5V means the circuit goes off-hook and puts the audio through). I am shure there must be some circuits available somewhere ? What do you guys use for phone patching ? (Not legal over here). Thanks. Please send any replies via Email. Keith ZS6TW ------------------------------ Date: Tue, 30 Nov 1993 16:41:04 GMT From: swrinde!sgiblab!news.kpc.com!kpc!nat@network.ucsd.edu Subject: TMS32010 To: ham-homebrew@ucsd.edu Hi, Anyone know of a place where one could buy the TI TMS32010 DSP chip in single quantities? Any idea how expensive this chip is? I know this chip is at least 8 years old. My adviser in graduate school had a tms32010 system development kit from TI and I implemented many filters on it. While we are on it does TI still sell the development kit for the tms32010 ? The kit had a build in assembler and all you had to do was to download the assembly code in ascii from a host machine. The development board intercepted the incomming stream and assembled it on the fly. On the whole it was a neat set up. Thanks in advance. Nat. -- ------------------------------------------------------------------------- Natarajan Gurumoorthy AB6SJ Kubota Pacific Computer, Inc. nat@kpc.com 2630 Walsh Avenue Phone 408 987 3341 Santa Clara, California 95051. ------------------------------ End of Ham-Homebrew Digest V93 #120 ****************************** ******************************