RF Interference

I live in downtown Seattle and my apartment sits between two hills which both have huge radio antennas. As a result, both of my Marshall amps pick up National Public Radio as if they were radios and not guitar amps. Would a good power conditioner help get rid of the interference? Is there any solution that costs less than $200.00? Any help would be greatly appreciated. By the way my guitars are completley shielded and I'm using high quality cables, so at this point I really need to find a way to eliminate the RF interference from the amps ASAP.

Cheers,

CJ