TomCat wrote
If you have a multimeter, measure the neutral-earth voltage at an electrical outlet. BE CAREFULL...LIVE MAINS VOLTAGE.....
The voltage should be really low as in less than 1 volt AC. If the voltage is about 1V or more then you have a bad neutral/earth in your house wiring.
Get an electrician in to find and rectify the fault.
How old is the house you are staying in?
A high neutral/earth is both detrimental to equipment as well as posing a safety hazard.
The neutral/earth voltage is exactly 1 volt. I guess that's bad.
But the noise is definitely from the fence.. Here's what I saw. The box which contains the batteries and electronics has a ground line, which goes to a physical stake in the ground. However the plug which connects this box to the mains power has no ground on it. Would that have any effect?
What about a magnetic field? This sounds a bit silly - but could a large enough voltage on the fence somehow affect the speaker in my audio equipment?
