[Elecraft] Re: K1 on USB CW
Vic Rosenthal
vic at rakefet.com
Thu Jun 17 19:59:03 EDT 2004
Leigh L. Klotz, Jr. wrote:
> I just picked up a copy of the June CQ in the airport bookshop and p.28
> has a sidebar by K2MGA (CQ Publisher) on the history of SSB:
>
> Regardless of how the SSB signal was
> generated, the 455 kc USB signal was mixed up
> to 9 Mc. Using a converted war-surplus
> BC-458 transmitter...as a VFO, the
> 4.0 to 5.3 Mc output was either added
> to or subtracted from the 9Mc SSB
> signal. That produced a USB signal on
> 20 meters or an LSB signal on 75 meters.
This is just wrong. Say you generate a USB signal at 9 MHz from a 1 KHz
audio tone. The (suppressed) carrier of the generated USB signal is at
9.000 MHz and the upper sideband is at 9.001 Mhz. Then mixing with a
5.0 MHz VFO would give sum frequencies of 14.000 and 14.001 MHz as well
as differences of 4.000 and 4.001 MHz. This is USB in both cases.
Of course, the VFO would tune in opposite directions.
Even a CW operator like me can add and subtract!
--
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco
More information about the Elecraft
mailing list