In a message dated 98-06-03 11:19:58 EDT, 10eesfams2mi@mass1-pop.pmm.mci.net
writes:
> Nice logical theorem snipped out, love the plastic wrap idea. My
> neighbor uses a jug of saltwater filled with pennies for an equipment
> ground, and sticks his cables in a foil wrapped jar. He says it works
> because his 40 foot tower in the middle of the 90 foot tall trees
> has NEVER been hit.
Duh! The 40 foot tower is probably within the 'cone of protection'
afforded by the 90 foot trees. He could stand on one leg singing Yankee Doodle
and achieve the same results.
>
> > P.S. Good luck - you will need it as much as if you leave your
> > tower ungrounded, and the charge has to find its own path to
> > ground.
>
> That indeed is a problem.
The problem is that a tower in the open IS a potential target. And the
problem is also that it's ungrounded. You have big potential differences
existing and the charge WILL find a path from the tower to ground somewhere.
It'll arc somewhere due to the potential differences either from the tower to
the base or tower to rebar or rebar to earth or something. What you're trying
to do is PREVENT the strike by offering a low impedance path to earth (again,
many assumptions).
>
> In my case, I don't worry much because both of my very tall towers
> up on this ridge in the open pastures ARE grounded quite well
> (through a small spark gap at each leg end). When I pull the feedline
> and control connections OUTSIDE the house, I just add additional
> assurance lightning is LESS likely to follow the cables into the
> house, or lightning that hits the power lines is less likely to go
> through the house to the massive tower ground.
Right. If you can keep the lightning from entering the building, you
really don't have to do much INSIDE the building.
Cheers, Steve K7LXC
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