On Sun, 12 Mar 2006 22:39:51 -0500, jawod wrote:

If I run a low gauge wire from that earth ground to the
main box ground, then this is prevents ground loop? What if the
distance to the mains box is 60 feet?

Hi John,

This is required by code. Violate code and insurance can dump your
policy faster than a lightning strike.

The whole point of that wire is to prevent ground loops - this one
being the mother of all loops. If and when lighting gets snubbed by
your arrestor, it will bury that charge into this inferior ground (the
non-code unconnected ground that is), lift that ground's potential,
and that potential will follow its way into the shack (along the
shield) to find your safety ground (which is far better suited for
that path) and you might happen to be sitting on the shoulder of that
current superhighway.

The resistive earth path between your arrestor ground and service
ground is not nearly as attractive as the path from safety ground,
through power supply, through chassis, through transmission line
shield to the arrestor. It is a rare power supply that breaks that
path's DC continuity, and a rarer one that RF isolates it both. Unless
you are running solely on battery, no charger, and no accessories
connected to the rig - there is a path to ground that lightning will
find as an alternative.

60 feet is trivial for safety (the RF in lighting is more LF or MF
than HF).

73's
Richard Clark, KB7QHC