While intended for audio and video production houses, it is a very
good over view of the "whys" of
NEC grounding.

http://www.campuspa.com/downloads/grounding_tutorial.pdf

The graph on page 28 is very interesting as it shows the noise on a
"typical" ground conductor.
And the graph on page 31 shows the impedance of a 10' section of wire.

Please not the comments Mr. Whitlock makes are directed at the audio
video world.
But his explanations are helpful in gaining understanding that the
house mains, and the
house NEC ground are NOT designed with RF in mind!

Mr. Whitlock is one of the true wizards in the high end audio world.
His Jensen transformer company markets the best audio isolation
transformers available.



Will Sent me this link. A report on real world noise radiation from
"balanced" power distribution
systems.
http://fjallfoss.fcc.gov/prod/ecfs/r...t=6516082 173


Terry