[TowerTalk] Ground wire gauge

[Jim Brown]

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