VR2BG wrote: Since it's only certain skimmers sending wrong-freq spots, you
can imagine all you want Pete, it won't change the fact that the receivers
have spurious responses & if signals appear there, they will be spotted on a
frequency or even band that is outright WRONG.
There is no need for great immagination as all the cases can be technically
explained. The simpler case is harmonics, especially odd ones. Strong 7
MHz CW signal can be easily decoded on 21 MHz. I guess we all experienced
that in local environment on the dead bands.
Image freq in QSD can be easily distinguished by much lower signal-to-noise
ratio. These are physical facts and they would be more often recorded by
hard working 24/7 Skimmers showing millions of spots. Unfortunately even
our latest analog radios tend to have IF in HF range for narrow roofing
filters.
Just beware that we are poluting radiowaves with kW of HF power.
Professionals are using less in smart cells, military OTH radars much more.
Robots are more accurate than hams!
LP MMM S56A
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