Date: Wed, 24 Nov 93 04:30:44 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 #112 To: Ham-Homebrew Ham-Homebrew Digest Wed, 24 Nov 93 Volume 93 : Issue 112 Today's Topics: [Q] transistor info for OC83B Anybody marketing HF kits ? Direct Conversion with CW RIT single sideband generation 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: Mon, 22 Nov 1993 10:32:32 GMT From: munnari.oz.au!spool.mu.edu!howland.reston.ans.net!pipex!Q.icl.co.uk!dsbc!iclbra!ss11!kyt@network.ucsd.edu Subject: [Q] transistor info for OC83B To: ham-homebrew@ucsd.edu Hello world, Sorry if this is the wrong place for this posting. I am looking for a spec sheet for a 1960's germanium transistor made by Mullards of type OC83B. It forms part of the circuit for a tachometer in a Smiths instrument. Many thanks in advance... regards Kai Tsang ------------------------------ Date: 23 Nov 93 20:03:36 GMT From: ogicse!emory!gatech!howland.reston.ans.net!agate!etch-eshop.Berkeley.EDU!ron@network.ucsd.edu Subject: Anybody marketing HF kits ? To: ham-homebrew@ucsd.edu I'm wondering, does anyone know if (who) markets Ham radio kits. I'm not yet involved in the hobby, But I could get interested in building an HF rig. I seen mentioned "Daves kits" here om the net. Thanks Ron Viegelahn ron@etcheshop.Berkeley.EDU ------------------------------ Date: Tue, 23 Nov 1993 18:56:11 GMT From: sdd.hp.com!cs.utexas.edu!math.ohio-state.edu!magnus.acs.ohio-state.edu!usenet.ins.cwru.edu!news.csuohio.edu!vmcms.csuohio.edu!R0264@decwrl.dec.com Subject: Direct Conversion with CW RIT To: ham-homebrew@ucsd.edu I had a HW8 with added RIT, and loved to be able to go above or below the zero-beat point. Also, zero beating was a snap -- turn off the RIT, zero beat to zero frequency, and flip the RIT back on and adjust it to a comfortable audio freq. This does not seem to be possible with dual conversion SSB/CW equipment. Is it? ------ Phil Emerson, AA8JO ------------------------------ Date: Fri, 19 Nov 1993 13:48:24 GMT From: EU.net!ieunet!tcdcs!news.tcd.ie!unix2.tcd.ie!mdennehy@uunet.uu.net Subject: single sideband generation To: ham-homebrew@ucsd.edu Newbie Question Time : Why bother to eliminate the offending sideband in the transmitter at all ? If the RX is good, It shouldn't be confused when you tell it to listen to an ssb signal and then tune it to a DSB one, should it ? Or is the idea of transmitting DSBSC not a good one (ie. wastes EM bandwidth) ? Hiding behind my newbie status to avoid great big red flaming followups, EI5EDB. -- Mark "Rain Man" Dennehy, Ham Radio : EI5EDB (2m FM only) :-( J.F. Engineering Undergrad, Internet : Mdennehy@Unix2.tcd.ie Trinity College Dublin. Telepathy : Mdennehy@Mars.Red.Planet ------------------------------ Date: Tue, 23 Nov 1993 17:12:48 GMT From: concert!news-feed-1.peachnet.edu!emory!kd4nc!ke4zv!gary@decwrl.dec.com To: ham-homebrew@ucsd.edu References <2cm8so$94p@hpscit.sc.hp.com>, <1993Nov22.161752.23379@ke4zv.atl.ga.us>, <2crvn5$j5h@hpscit.sc.hp.com> Reply-To : gary@ke4zv.atl.ga.us (Gary Coffman) Subject : Re: single sideband generation In article <2crvn5$j5h@hpscit.sc.hp.com> rkarlqu@scd.hp.com (Richard Karlquist) writes: >In article <1993Nov22.161752.23379@ke4zv.atl.ga.us>, >Gary Coffman wrote: >> >>>The non-correlation of interference is only worth 3 dB. >> >>I've seen this argued back and forth. It's true if you're just using >>a summer as a correlator. But more advanced correlators are possible. > >That sounds very interesting. Can you give us an more information >about it? Well it's tricky in the analog domain, but I've seen one circuit that takes advantage of the common mode rejection of opamps to derive a channel that has all the non-correlated noise and interference but with the desired common signal suppressed by 60-80 db by the opamp's common mode rejection. The anti-correlated signal is then inverted and added back to the main channel, cancelling the undesired noise and interference. Needless to say, the balance of this circuit is critical to it's operation. It should be much easier to implement in DSP. Note this technique assumes ISB detection as well since it requires two separate audio channels. It's not a classic DSB detector. If true IF DSP is available, this could all be combined into one digital circuit. Gary -- Gary Coffman KE4ZV | Where my job's going, | gatech!wa4mei!ke4zv!gary Destructive Testing Systems | I don't know. It might | uunet!rsiatl!ke4zv!gary 534 Shannon Way | wind up in Mexico. | emory!kd4nc!ke4zv!gary Lawrenceville, GA 30244 | -NAFTA Blues | ------------------------------ Date: 19 Nov 1993 00:39:49 GMT From: dog.ee.lbl.gov!agate!howland.reston.ans.net!vixen.cso.uiuc.edu!sdd.hp.com!hpscit.sc.hp.com!rkarlqu@network.ucsd.edu To: ham-homebrew@ucsd.edu References <1993Nov15.164550.18931@cs.rit.edu>, <2c8ohb$abo@hpscit.sc.hp.com>, <2cg9h9$1qqf@ilx018.intel.com> Subject : Re: single sideband In article <2cg9h9$1qqf@ilx018.intel.com>, Doug Braun wrote: >This has been a fascinating discussion! I have been reverse-engineering >an old H-P vector impedance meter without benefit of the manual, >and it does something very much like SSB generation. > >So: the question is: What kind of circuit will take a RF signal >anywhere between .5 MHz and 110 MHz, and generate a signal exactly 5KHz >higher, with excellent spurious rejection? It sounds like the SSB >"phasing" technique, but with a single fixed audio frequency instead No phasing techniques here. It's just a .5 to 1 MHz. VCO with an offset phase locked loop. If this loop goes out of lock, the "SEARCHING" light on the front panel lights up. On ranges above .5 to 1 MHz., harmonics of the VCO are used. This technique would be useless for generating SSB voice signals. Rick Karlquist N6RK rkarlqu@scd.hp.com >Doug Braun Intel Israel, Ltd. M/S: IDC1-41 > Tel: 011-972-4-655069 dbraun@inside.intel.com ------------------------------ Date: 23 Nov 1993 03:42:02 GMT From: swrinde!sdd.hp.com!col.hp.com!news.dtc.hp.com!hpscit.sc.hp.com!rkarlqu@network.ucsd.edu To: ham-homebrew@ucsd.edu References <2brk68$qh5@reznor.larc.nasa.gov>, , <1993Nov22.210435.3253@torreypinesca.ncr.com> Subject : Re: Phase-lock to WWV ? >>His clocks at the NIST in Boulder are across the hall from the atomic >>clock that is the primary standard, and run all the time. They are >>calibrated by the atomic standard, when it runs, which is relatively >>seldom. >>73, doug > >Oh no! You mean the WWV clock I have heard for the last 20+ years aren't >tied directly into the atomic standard? I'm shattered, having had this image >in my head for all this time of some titanium-hulled device on a marble slab >in a sealed vault to which WWV clock was attached. Funny how images like >that, no matter how ludidrous, remain with us as long as there's no reality >to displace them. > > Kevin Sanders, KN6FQ | ___ | Let me try to shed some light on this. First, you need to distinguish between a usable clock that keeps time over long periods of time and a laboratory frequency standard that measures frequency during the occasional times when it is running. The working clocks at NIST consist of a bunch of mainly HP 5061 and 5071 cesium atomic clocks, which are kept in controlled temperature and humidity boxes. Their time is averaged to get the official NIST time, which is then averaged with other country's times and the US Naval Observatory's time. Worldwide Universal Coordinated Time (UTC) is kept in Paris by the French equivalent of NIST (BIPM) and is the average of the best 200 or so clocks in the world. The laboratory frequency standards that fill a room, and are called NIST-4, NIST-6, NIST-7, etc. are continually being improved upon and run only occasionally for operational purposes. They are used to attempt to measure absolute frequency error in the on-line clocks. The physics of the small on-line clocks limit the absolute frequency accuracy to a few parts in 10 to the 13th while the lab standards are known to be good to a few parts in 10 to the 14th. Once the error in the on-line clocks is known, it can be corrected for since an HP 5071 is stable to a part in 10 to the 14th, for example. Rick Karlquist N6RK HP Santa Clara Division (where the HP5071 atomic clock is made) rkarlqu@scd.hp.com ------------------------------ Date: 23 Nov 1993 03:23:17 GMT From: swrinde!sdd.hp.com!col.hp.com!news.dtc.hp.com!hpscit.sc.hp.com!rkarlqu@network.ucsd.edu To: ham-homebrew@ucsd.edu References <1993Nov20.174843.13453@ke4zv.atl.ga.us>, <2cm8so$94p@hpscit.sc.hp.com>, <1993Nov22.161752.23379@ke4zv.atl.ga.us> Subject : Re: single sideband generation In article <1993Nov22.161752.23379@ke4zv.atl.ga.us>, Gary Coffman wrote: > >>The non-correlation of interference is only worth 3 dB. > >I've seen this argued back and forth. It's true if you're just using >a summer as a correlator. But more advanced correlators are possible. That sounds very interesting. Can you give us an more information about it? >I understand that the doubler technique can be used with voice too. >The time constant of the PLL has to be altered to a fast attack, slow >decay curve. This may introduce a bit of distortion at the beginning >of syllables if the attack timing is wrong. This might be made to work after a fashion if you run the signal through a delay line before mixing it with the recovered carrier so that the PLL has a chance to lock up first. Anyone know of any actual experiments? >Gary Coffman KE4ZV | Where my job's going, | gatech!wa4mei!ke4zv!gary Rick Karlquist N6RK rkarlqu@scd.hp.com ------------------------------ End of Ham-Homebrew Digest V93 #112 ****************************** ******************************