[Elecraft] OT: USB and LSB - How we got there

[Don Wilhelm]

Ken and all,

BUT, that information is incorrect.  The sidebands will NOT invert with 
a 9 MHz IF and a 5 MHz VFO.

A little simple math should convince you.
Assume a 9.000 MHz IF and a 5.200 MHz VFO and a modulating frequency of 
1kHz.

9.000 + 5.200 = 14.200 for the carrier frequency
9.001 + 5.200 = 14.201 for the modulated frequency.  That is Upper Sideband.

9.000 - 5.200 = 3.800 for the carrier frequency
9.001 - 5.200 = 3.800 for the modulated frequency - that is also USB.

The early SSB generators (Central Electronics 10A for one) did use a 9 
MHz SSB generator frequency, but there was a switch to change sidebands.

If you have a 5 MHz IF with a 9MHz VFO as was used by Hallicrafters, the 
sidebands will invert between 75 and 20 meters.  Try the addition and 
subtraction to convince yourself.

73,
Don W3FPR

On 2/14/2018 3:08 PM, Ken G Kopp wrote:
> Here's a URL to a website with lots of information:
> 
> http://www.ac6v.com/73.htm#LSB
> 
> Or, search "BC-458 command set transmitter" and
> "Central Electronics 10A" with your browser.
>