On 4/12/12 12:02 PM, David McGaw wrote:
Best would be to have a lightning rod in the vicinity of and above the
antenna. A sharp-pointed rod does not attract lightning, it REPELS it
and has a cone of protection under it. While the effect is not
understood, it apparently discharges the surrounding air through corona
discharge - the sharper the better.
Cone of protection it is, but it's because the lightning preferentially
hits the rod, rather than something below it.
There's no discharging the earth/cloud capacitance. That theory has been
thoroughly debunked, both analytically and experimentally. There's some
great papers by some scientists at Erico in Australia where they were
looking for "better designs" for lightning rods, so they set up a test
facility to replicate the charge distributions and fields in the
"prestrike" time. This is very much trickier operation than testing for
the discharge itself, or for EMP, where you just need a big Marx
generator. It's essentially a high voltage arbitrary waveform generator
into a carefully designed TEM test cell of sorts.
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