I think that you have the answer to the riddle Ian. 9 megacycle filters were not available until about 1960 with the second generation of transceivers. By the time of Galaxy 3 and 5, NCX-5, Swan 350, etc the need for the USB/LSB selection was passed, but we stayed with the tradition.
I have seen some remarks that would indicate that the Elecraft is unique in being able to select the sideband, but I have not had a transceiver that would not. Even back to the Hammarlund HX-50, if I remember correctly one could select the sideband. I know on the two transceivers I have in the shack, Kwd TS-850 and Yaesu FT-900 when you select SSB it puts you on the preferred sideband, but if you press the button again it puts you on the other sideband. Cookie, K5EWJ --- Ian White GM3SEK <[EMAIL PROTECTED]> wrote: > WILLIS COOKE wrote: > >It does not give the same sideband on 80 and 20. > You also have to > >consider that the rotation of the tuning capacitor > of the VFO turns the > >opposite direction for 20 as it does for 80. > > The direction of tuning is not what inverts the > sideband. > > The only thing that inverts the sideband is if the > SSB frequency is > subtracted in the mixing process. So: > > 9MHz USB + 5MHz VFO = 14MHz USB > > 9MHz USB - 5MHz VFO = 4MHz USB - sideband is not > inverted. > > But in Norgaard's 'New Approach to SBB Generation' > in QST, June 1948, > the SSB is generated on 5MHz and the VFO is around > 9MHz, so: > > 9MHz VFO + 5MHz USB = 14MHz USB > > 9MHz VFO minus 5MHz USB = 4MHz **LSB** - now the > sideband is inverted. > > If anyone is still in doubt about this, words aren't > going to help any > more. Please take a few minutes with a pencil and a > calculator, punch in > some numbers and verify it for yourself. > > > -- > > 73 from Ian GM3SEK 'In Practice' columnist > for RadCom (RSGB) > http://www.ifwtech.co.uk/g3sek > _______________________________________________ > Elecraft mailing list > Post to: Elecraft@mailman.qth.net > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > Willis 'Cookie' Cooke K5EWJ _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
