First off, some radios like the GE Superadio series and other AM/FM/SW
portables are inherently noisier on AC power. Not much you can do about it
other than use batteries for serious listening. Receivers meant for AC power
only are usually better shielded and filtered.

What I'd do is plug the radio in and shut off all other power box circuit
breakers except the circuit the radio is on. If the noise persists, it's
either the radio or some other electrical device hooked into that circuit.
If the noise goes away, turn on circuit breakers one by one until the noise
comes back... then investigate items on the last breaker thrown.

Could also be a functional, yet marginal power transformer up the street, a
neighbors microwave or window air conditioner, or even bad wiring in your
walls or at the pole. Electrical noise can be tricky to find. Good luck!

"Daniel J. Morlan" wrote in message
m...

Radios sound great with batteries, but when plugged in, sound is
appreciably poorer. Is there a real solution to this?