Al Arduengo wrote:
One of my portables which I like has a problem with noise. The odd thing is
that when using the mains input the noise appears only on the lower SW and
all MW frequencies. The lower I go the more it becomes a whistle. This
occurs whether I use the supplied AC adapter or a DC-DC converter. For the
veterans, does this imply that the input jack itself is somehow generating
lower frequency noise? Has anyone else ever experienced this sort of
thing? I would consider a ferrite bead on the cord at the adapter but
since it seems to be related more to the jack than the adapter, would a
bead on the adapter cord right next to the jack input make any sense? Any
other suggestions?

Thanks very much.
-Al

Well, I have a Grundig Satellit 800 and on the HF bands it seems like
I'm hearing strong heterodynes quite frequently. I am running my
computer near the radio and I'm wondering if this is the culprit or is
this just 'normal' behavior for this particular radio.
As for noise from the power lines, I get that even when the radio is
off. I can't hear it, but I can SEE it in a spectrogram. My scanner has
that same issue with power line noise. I've tried jiggling my cords
around and moving my AC adapters to different places on my surge
protector but to no avail. Know how to fix these problems?

Jeff Seale
Satellit 800, YB550PE, DX440, BC780, Pro95
Louisville, KY