>Actually, you can pick them up much farther than that. Here is what you
do.Take an AM radio and tune into something like 1600AM. As you get near
the wire, the signal ( sounds like noise ) will get louder. It has a
distinct frequency, similar to the sound the dog hears before it is shocked.
Great, so I should be able to use a simple AM receiver circuit and simply
bandpass the transmitted freq.
I'll publish the results here soon.
Dave Everett.