In my house I am picking up an AM radio station (Oldies 1310) on both my phones and PC speakers (when the computer is off), sometimes barely there and other times very noticeable. On the phone, it does not seem that the other party can hear the music except maybe as background noise through the receiver. I have noticed this problem on all of my phones, but the filter that the highspeed modem requires on all extensions seems to take out the noise on all but one phone.
The kicker was tonight, when my subwoofer for my home theatre started doing this. I’ll just bullet some facts.
- The sub in question is connected by about 25 feet of TV grade coax.
- None of the other speakers (or the other sub, which is on another AC plug but shares the same output on the AV receiver) is acting up.
- When I unplug the cable from the sub, the radio stops.
- When I unplug the cable from receiver, the radio volume is reduced but still audible.
- If I jigger the cable in the sub, the radio cuts out all together momentarily.
- If I touch the metal backing of the control panel for the sub, the volume doubles (at least, maybe triples).
- The volume knob for the sub does not affect the radio output volume at all.
- The sub uses a non-grounded (two prong) AC plug.
I also have a touch lamp in the bedroom that turns on and off by itself, usually if someone uses or touches a light switch but also by touching the phone. This is occasional and difficult to reproduce with regularity.
So, what say you all? Obviously the wiring in the house is acting like an antenna and is picking up AM 1310 (or one of the harmonics), but how is the signal getting demodulated? Is this a ground issue? I don’t really care if I can’t fix the phones, but the sub is right behind the couch and is very noticeable.