Here's a couple of good links...

http://www.amgroundsystems.com/ags.htm

http://www.findarticles.com/p/articl...9/ai_101517773



"Peter Duniho" wrote in message
...
"JohnMcGrew" wrote in message
...
[...] The ground system consists of a series of wires, buried
underground, each the length of the tower, and located at 10 degree
(IIRC)
radials emanating from the tower base. [...]
with each radial the same length as the tower.

I don't know where you got this from. If you look at the arial pictures
of the
KFI tower, you'll find that it is barely 100 feet away from industrial
buildings.

I don't know where he got it either. We live right next door to several
tall AM transmitting towers (at least three, maybe four...I'm too lazy to
go
look out the window and refresh my memory), all of which are taller than
the
distance between the antennas and our house (and dozens of other houses
around them too).

Maybe some AM towers have the radiating underground wires, but clearly not
all do.