This is a question in the December 2009 QST article "The Doctor is In" on page 45. He explains that the calculation with a VFO range of 5 to 5.5 Mhz is:
9 + 5 = 14 9 + 5.5 = 14.5 9 - 5 = 4 9 - 5.5 = 3.5 >From the article: "The subtractive translation reversed the frequency >relations (and the VFO tuning direction) to result in LSB." The circuit >design apparently saved quite a bit of cost in those days. Byron KI6NUL On Dec 3, 2009, at 7:15 AM, Bob Cunnings wrote: > 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? ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
