Dan Jacobson wrote:
My ham radio 110-13.8 V power supply interacts with my electric
frying pan. No matter how far away in the house I plug them in, there
is a harmonic that causes the power supply to make a loud hum.

I must choose between rag chewing and food chewing. Help. What gizmo
can I purchase to filter out the resonance between them? Actually, it
only happens when the pan is switched to "low", not on "high".


As Dave said, a battery. It will give you emergency power
for the rig during field day or an outage, too. You can
keep it charged by running it in parallel with the supply
when the rig is on and the frying pan isn't.

Ed