Date: Mon, 9 May 94 04:30:29 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 #123 To: Ham-Homebrew Ham-Homebrew Digest Mon, 9 May 94 Volume 94 : Issue 123 Today's Topics: DC-100 Mhz VCO Chip (2 msgs) diode ring detector with smd's? EEPROM info ? Metal-Encased Mica Caps RTTY with regular modem? 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: 8 May 1994 14:50:07 GMT From: pacbell.com!ohlone.kn.PacBell.COM!jlundgre@decwrl.dec.com Subject: DC-100 Mhz VCO Chip To: ham-homebrew@ucsd.edu Dean Gelabert (dean@splinter.coe.neu.edu) wrote: : Hi: : Does anyone know if there is such a thing as an inexpensive DC-100Mhz : vco chip out there? : -Dean Well, if it's at DC, then it's called a power supply. If it is at 100MHz, then it's called a transmitter. You probably won't find a device that will go much more than 1 or 2 decades, for a reasonable price. The voltage at 100MHz, let's say, it 100 volts. At 100KHz, it would be a tenth of a volt. What would it be at DC? Microvolts? This device you want would have to be lon-linear to meet those requirements. -- @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ John Lundgren - Elec Tech - Info Tech Svcs @ STD DIS- @ @ Rancho Santiago Community College District @ CLAIMERS @ @ 17th St. at Bristol \ Santa Ana, CA 92706 @ APPLY... @ @ VOI (714) JOHN GAB \ FAX (714) JOHN FRY @ @ @ jlundgre@kn.pacbell.com \ jlundgr@eis.calstate.edu @ @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ ------------------------------ Date: 8 May 1994 19:10:13 GMT From: ihnp4.ucsd.edu!agate!headwall.Stanford.EDU!w6yx.stanford.edu!stevem@network.ucsd.edu Subject: DC-100 Mhz VCO Chip To: ham-homebrew@ucsd.edu In article dean@splinter.coe.northeastern.edu writes: >Hi: > Does anyone know if there is such a thing as an inexpensive DC-100Mhz >vco chip out there? > >-Dean The closest chip I can think of is the Motorola MC1648 (I think thats the right number). You can make a reasonably good varactor tuned VCO out of it. DC to 100 MHz would not be practical for a single oscillator though. Generally, that kind of tuning range can be had by mixing two UHF oscillators together and taking the difference between the two. One oscillator would be fixed, say at 500MHz, the other would be tuneable from 500 to 600MHz. This allows wide tuning range and good linearity. Hope that helps Steve Muther WF6R stevem@w6yx.stanford.edu ------------------------------ Date: 8 May 1994 10:37:02 -0400 From: newstf01.cr1.aol.com!search01.news.aol.com!not-for-mail@uunet.uu.net Subject: diode ring detector with smd's? To: ham-homebrew@ucsd.edu Has anyone experimented with the surface mount HP-2800 hot carrier diodes as diode ring detectors for DC receivers?? I'm curious to know if they will give similar performance to regular HP-2800's? I need a _SMALL_ package for a receiver I'm building, and these would be perfect. Thanks for any replies! 72/73, Jim N0OCT jimn0oct@aol.com ------------------------------ Date: Sat, 07 May 1994 22:42:00 -0500 From: ihnp4.ucsd.edu!library.ucla.edu!europa.eng.gtefsd.com!news.umbc.edu!eff!news.kei.com!ub!galileo.cc.rochester.edu!ee.rochester.edu!rochgte!UUCP@network.ucsd.edu Subject: EEPROM info ? To: ham-homebrew@ucsd.edu Does anyone have any info on a pin - output schematic for EEPROM (93C46) such as Noika, Hitachi, or other brands. Please E-Mail me faster at my America Online address tonyingy@aol.com Thank-A-You ------------------------------ Date: 9 May 1994 08:03:19 GMT From: ihnp4.ucsd.edu!usc!nic-nac.CSU.net!charnel.ecst.csuchico.edu!olivea!inews.intel.com!ilx018.iil.intel.com!ilx049.iil.intel.com!dbraun@network.ucsd.edu Subject: Metal-Encased Mica Caps To: ham-homebrew@ucsd.edu A HT Amp I bought (RF Concepts) uses these funny capacitors in the RF circuits. They look like a collection of bits of mica and other stuff, clamped in a little metal frame. They are between 1/4" and 1/2" on a side. I also just got a "Surplus Sales of Nebraska" flyer, which lists some of them for sale. I was wondering: what is the advantage of this type of device? They look sort of crude, with an open construction that could let solder, moisture, etc. get in and mess them up. ------------------------------------------------------------------- Doug Braun Intel Israel, Ltd. M/S: IDC-42 (new mailstop!) Tel: 011-972-4-655069 dbraun@inside.intel.com "Partly as a reaction against the increasingly grubby image of punk and partly because of Paul Weller of The Jam's enthusiasm for sharp 60's beat styles, 1979 wittnessed a mod revival. Largely local to London, this consisted principally of swarms of aggressive young mods parading down Caranaby Street (once the home of 60's fashion but now a tourist trap) wearing period parkas decorated with mod insignia, looking for trouble." ------------------------------ Date: 8 May 1994 14:57:10 GMT From: pacbell.com!ohlone.kn.PacBell.COM!jlundgre@decwrl.dec.com Subject: RTTY with regular modem? To: ham-homebrew@ucsd.edu No. RTTY is narrow band FSK. Modems don't do that narrow a band, but use as much of the the full 300 to 3700 Hz bandwidth as they can. They actually put out an audio carrier. What you want to do is shift your RF carrier with the RTTY signal. So the RTTY pulses would be fed into the transmitter oscillator or VCO. If you have an RTTY, it probably puts out current loop, and most modems don't handle current loop. -- @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ John Lundgren - Elec Tech - Info Tech Svcs @ STD DIS- @ @ Rancho Santiago Community College District @ CLAIMERS @ @ 17th St. at Bristol \ Santa Ana, CA 92706 @ APPLY... @ @ VOI (714) JOHN GAB \ FAX (714) JOHN FRY @ @ @ jlundgre@kn.pacbell.com \ jlundgr@eis.calstate.edu @ @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ ------------------------------ End of Ham-Homebrew Digest V94 #123 ******************************