Tom Rauch wrote:
> I'd hate to see us start thinking a simple "flip sideband" would prove
> anything. It's the crap 6-20kHz away that means we have a major problem.
>
> 73 Tom
If products can be heard 6-20 khz away you can almost bet that abnormal
trash can be heard on the opposite side band.
I am not advocating that listening on the opposite side band be the ONLY
test done for IM. I am simply suggesting that it be a first thing to do
on the air for everyone to help identify poor signals. Of course tuning
around can give more detailed information, if you know what you are
looking for.
Try explaining to Joe appliance operator how to pick out IM products by
tuning his receiver across the band and distinguish it from the noise
caused when his upper side band receiver is 2 or 3 kc below a 40 over
upper side band signal. And why it sounds different when he tunes to the
high side of that same signal.
The reason I suggest looking at the opposite side band is because it is
simple to do, precise in frequency and you can get a fairly ball park
indication of relative levels. Something most everyone can do. It is a
start.
73
Gary K4FMX
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