[Amps] Checking for IMD

[Tom W8JI]

> Switching side bands IS the same as tuning your receiver 
> the width of your
> filter.

No. It is not the same.

The filter is offset from the carrier in both the 
transmitter and the receiver, and you will miss the 
close-spaced high audio frequency tones that would be in the 
clear if you tuned.

 >If you have a 3 KHz wide filter and listening to the upper 
side band
> and you tune down 3 KHz with the tuning dial, you have 
> moved the receiver
> pass band the same amount as when you switch to lower side 
> band and leave
> the receiver dial alone.

No it isn't. The transmitter has a 300Hz or some filter 
offset from the carrier.

Assuming the receiver has the same, the error is 2X the 
offset. This does not occur if you tuned down the filter 
bandwidth and stayed on the same sideband.

73 Tom