Well, down here in the monsoon belt where we typically get more than 100
thunderstorm days a year, we seem to prefer separate ground systems for the
tower
and the shack. BUT....
Most of us who would avoid damage build a serious ground system with enough
capacity to sink almost any possible hit. A typical tower ground consists of
first drilling an 8" well hole in the bottom of the tower excavation to well
below the permanant water level, then dropping enough salvaged oil field drill
stem (basically schedule 80 6" steel pipe) to stand in the hole and protrude
well above ground level. Lugs are welded just above ground level to attach
ground conductors to the drill stem.
The tower base is then installed, and the concrete is poured around the drill
stem ground rod. When the concrete has cured we run suitably heavy
conductors, typically 3/4 to 1 1/2 inch copper tubing, from each leg of the
tower to
the ground rod.
The coax and rotor cables from the tower run to lightning arrestors housed in
a well grounded aluminum "pickup tool box" and from there to a bulkead
that's grounded to the house ground system. That makes a total of three
separate
ground systems.
In my case it's been 14 years with 3 to 5 hits a year, about 60 hits total,
no damage. And no, the tower base did not explode with the first lightning hit.
So I would say it works.
73 Pete Allen AC5E
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