Here is my situation. I am pretty sure noise is from switching power supplies.
Unfortunately, it tends to put noise right where I don't want it. Like bottom
of
160, 80 and 40m. Typically the noise is 20-25 kHz of S8-9. One hears
modulations on it and the whole band moves up and down in
David,
I think the divide and conquer approach is the best. Hopefully the source(s)
are in your own home, much easier
to resolve. What I did was to connect a 12 volt battery to my K3 so I could
listen without needing AC. Then shut off the main
breaker to the house. The noise was gone
