Hi,
>From all the responses I have rcv'd since posting this question, it is
clear there are several issues when ground rods are to be used.
One is the dissipation away of huge amounts of current from lightening
strikes. The other, and really my concern, is the grounding of the
station
to avoid RF making things "hot" in the shack, and being sure the amplifier
has a good ground for it's own purposes. Lightening strikes in Hawaii,
at least here on Kauai are very rare -- such a storm is, maybe, every
three or more years apart, and then brief and mostly up in the high country,
or out offshore on the ocean.
For lightening, the rod going vertically into the ground seems correct.
For RF grounding the station, several have said they use a different
approach. Put the long ground rods horizontally from a foot or so
to 18 inches deep in trenches dug via shovel and watered a few times.
One fellow has such dug in, in a U going around his house and tower base.
Others, with difficult soil in which to go down 8 feet, have them in
various
patterns horizontally under the soil. Such an array seems to dissipate
to the earth the needed RF currents from the shack and keeps all in the
shack at a constant, steady "earth" potential eliminating the possibility
of ground loops when essential gear is "grounded" and other "boxes"
just use the outer shield of the coax to establish RF ground potential.
Not at all sure exactly how all this works; ARRL books show a ground bar
along the back of the table upon which all gear is placed. Each box has
a ground strap out to this bar. Apparently this set up can, at times, be
a
source of trouble. Also, the use of copper tube as this bar is a real
no, no! Am told the round tube is a great RF feedback path; that is
why rectangular braid/bar is the proper ground strap to be used, not
tubing.
Anyway, has been an instructive thread, thanks to all who have sent
personnal notes directly to me, and also those who have sharred
their inputs with the reflector.
73, Jim, KH7M
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