> The good news is that I own an Elecraft K3....the bad news is that I
> haven't bought a P3 yet. It sounds like a P3 is on my wish list and
> maybe later some type of portable SDR if I want to get really obsessive
> about this :)
Once you have a panadapter, it's easy to become obsessive in trying to get a
flat noise baseline without any switch-mode "bumps." Maintaining a flat
baseline on all bands can involve a lot of continuous work -- and not all of
it is switch-mode related. On the upper bands, repeating spurs from LAN
cabling, routers, etc. requires a lot of initial attention. The good news
is that I don't normally hear this interference from the neighbors as I do
with their switch-mode appliances.
The moment a bump shows up, I'm headed to the breaker panel to start the
next investigation. Before owning a panadapter, these noise sources
existed, but in the case of a low-level broad noise bump of say 40 kHz wide,
you can easily sweep the receiver and not really know there's a problem.
The noise floor gradually rises and it's easy to miss.
Another alternative to this is to use a noise nulling device from MFJ,
Timewave, or DX Engineering. N4LQ and others have been very successful in
eliminating noise sources by electrically steering a null from a sense
antenna. The degree of success largely depends on keeping the noise antenna
focused on receiving only noise and not desired signals. For example, a
ground mounted short vertical whip located near or under a horizontal
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