I just looked at my old copy of the NEW Sideband Handbook by Don Stoner W6TNS, copyright 1958 - I have 6th printing dated June 1966.
Page 94 shows the schematic of the Central Electronics 10B phasing exciter - and it DOES generate SSB at a fixed 9 MHz (unchanged from the 10A). The addition of a 5 to 5.5 MHz VFO will allow it to cover both 75 and 20 meters. I do recall conversations among SSB ops about the sideband selection for the various bands, but I cannot recall the details. For many years, I thought the sidebands were flipped between 75 and 20 meters with this 9 MHz generator and the 5 to 5.5 MHz VFO, but then I saw the math which says the sidebands did NOT flip with this mixing scheme - Oh well, the conventions are well glued in place - who will be real pioneers and campaign to get everyones mindset changed? Anyone for no QSOs? <G> 73, Don W3FPR Life is what happens when you are making other plans ----- Original Message ----- > It goes back to the original "SSB Jr." which was ultimately the basis for the FIRST > real commercially built SSB transmitter, the Central Electronics 10A. > It was a phasing rig and, the SSB selector was simply labeled SB1 and SB2. > Since 75 and 20 were the "popular" bands then for SSB (there wasn't a 40 meter > "phone" band back then!) the operators were "lazy" and used the SB1 > position for both bands (as I remember) yielding LSB for 75 and USB for 20. > Commercially and on the marine bands, USB has been the standard since day 1 > and far as I know. Why the amateurs have hung onto this old LSB on 40 > and below thing I don't know. I forget whether the 10A/10B/20A used a > 5 or a 9 mhz channel for SSB generation, but it DID "flop over" when > you went from 20 to 75 meters! Must have been generating SSB at 5 Mhz. > Anyhow that IS how that LSB/USB phenomenon got started: just plain > laziness! > Maybe one day they will mandate USB as the "normal" sideband? Didn't > they state that on the 60 meter channels? (USB only?) I'm sure that was > to get around the stupidity of the "monitoring" personnel who obviously > used receivers with USB filters only and they didn't know CW! I thought > it was a stupid move to "channelize" the 60 meter band on SSB only!!! > I supposed ARRL has too many irons in the fire now with the "rehashing" > of the amateur classes/privileges and BPL to worry about 60 meter > mode expansion? > _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net http://mailman.qth.net/mailman/listinfo/elecraft You must subscribe to post. Subscriber Info (Addr. Change, Unsub etc): http://mailman.qth.net/subscribers.htm Elecraft page: http://www.elecraft.com
