Er, hold on. you write: > Subtract 5 MHz VFO: > Carrier 9.000 - 5.000 = 4.000 MHz > Sideband 9.001 - 5.000 = 4.001 MHz > ==> USB
but shouldn't it be: Subtract 5 MHz VFO: Carrier 9.000 - 5.000 = 4.000 MHz Sideband 9.000 - 5.001 = 3.999 MHz ==> LSB Since we changing the VFO, not the IF freq? Bob NW8L On Wed, Dec 2, 2009 at 10:39 PM, Alan Bloom <n...@cds1.net> wrote: > On Wed, 2009-12-02 at 21:06 -0800, Alan Bloom wrote: >> On Wed, 2009-12-02 at 18:36 -0800, wb6r...@mac.com wrote: >> > LSB on the lower bands and USB on the higher bands is an artifact of >> > the mixing scheme, from the early days of SSB, of a 9 Mc IF mixed with >> > a 5.0 - 5.5 Mc VFO. (Yes, it was Mc in those days, not MHz.) Add and >> > you get 20m. Subtract and you get 80m. The subtraction results in >> > sideband reversal and so LSB became the "standard" for 80m. There is >> > really no reason now to not to just operate USB on all bands other >> > than tradition. >> >> I've heard people say that many times over the years but clearly it's >> not true. A 9 MHz IF set up for (let's say) USB will still be USB no >> matter whether you add or subtract the 5-5.5 MHz VFO. > > I just did a little Googling on the Internet (AC6V.com and elsewhere) > and discovered to my astonishment that this is an actual bona-fide > controversial subject among radio amateurs. Despite the fact that a > simple 2-minute back-of-the-envelope calculation is all it takes to > disprove the myth. For the record: > > Intermediate frequency: > Carrier 9.000 MHz > Sideband 9.001 MHz > ==> USB > > Add 5 MHz VFO: > Carrier 9.000 + 5.000 = 14.000 MHz > Sideband 9.001 + 5.000 = 14.001 MHz > ==> USB > > Subtract 5 MHz VFO: > Carrier 9.000 - 5.000 = 4.000 MHz > Sideband 9.001 - 5.000 = 4.001 MHz > ==> USB > > I can't believe people are actually arguing about this! > > Al N1AL > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
