On Sun, 12 Oct 2003 18:37:51 -0400, "AbbN"
wrote:

Hi,

How about using the ground in a 3 prong electrical socket???? Better than
nothing??? Dangerous??? I'm in a high rise
These are often very poor radio frequency grounds. A DC ground, or
for that matter a 60Hz ground has a very large skin depth (about .85cm
at 60Hz), so the entire conductor is useful, and the DC resistance to
ground is about all you have to worry about.

A good DC or even 60Hz ground can be an awful Radio frequency ground.
Even at 1 Mhz, the skin depth is a small fraction of a 1 mm, so all of
the corrosion and garbage occurs on the part of the conductor you
need. In addition the length of wire to the physical ground can be
very large, and even a straight wire has inductance, so long ground
line in addition to having poor conductivity, may also have
substantial inductance. Both make for a high impedance path to ground,
which is the last thing you want.

If it is a steel frame building, the building frame is probably a
much better RF ground then the ground lead in an outlet.