Larry wrote:



I've been involved in tower grounding (just a mast 1200' high with no
sails, if we can help it) for decades in broadcasting. The AM towers
are series fed, meaning they are insulated from ground but have two
trailer hitch balls a few inches apart (far enough so the 5, 10, 25 or
50KW transmitters don't make them arc in the downpouring rainstorms.)
Looking around Jim Hawkins' broadcast transmitter website, you can learn
a lot about lightning grounding from the professionals:
http://www.hawkins.pair.com/radio.html

Thanks for the cool links Larry. The most dangerous job in America is
that held by the tower jockeys.

The impedance thing is the biggest factor, you ever think to calculate
the slew rate of a lightening pulse? Something like 50MV/uSec!

"Resistance is futile, but impedance is rather complex"

Cheers
Martin