On Sat, 21 Jul 2007 22:52:18 -0400, Roger (K8RI) wrote:
While we're discussing the path to ground for lightning, remember
that the energy in lightning has a broad (several octaves wide) peak
around 1 MHz, NOT at DC. Resistance to earth of a typical ground rod
is on the order of tens of ohms, in addition the inductance of any
wires in between. A good radial system is likely to have a lower
(capacitive) impedance to earth than that at 1 MHz.
A wire connection the earth electrode certainly serves to minimize
charge buildup, but most of the fast transient that is lightning is
likely to be carried by the radial system, not the ground rods.
Jim Brown K9YC
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