Hi Don,
If you can possibly arrange it, run at least two opposing paths
for the lightning current to follow away from your rooftop
system. These two (four would be good too) paths should be
equalized as much as possible in their impedance
characteristics. The idea is to force relatively equal current
sharing in opposing directions away from the antenna. Most
lightning rod installations are done this way to minimize the
possible damage from EM fields inside the house. This is more of
a consideration if the antenna is centered in the roof than if it
is close to an edge and the down conductor can go straight down
that edge.
Tie everything together up at the top. And then tie that system
into your down conductors. Don't forget to ground the feedline
at your service entry ground point before bringing it into the
house.
73, Eric N7CL
>From: thaxton@ptgroup.com
To: <towertalk@contesting.com>
>Date: Thu, 14 Oct 1999 19:03:18 -0500
>
>I have just completed building a rooftop support for a rotor,
>mast and antenna. The support is steel,painted, and beefy! :)
>
>I have never had a beam antenna or rotor setup before so I would
>like some advice on how to ground everything, i.e. do I run the
>ground strap from the mast to the earth ground. Do I need to
>ground each component of my setup, i.e. antenna, rotor, mast? I
>am assuming since everything is metal and tied together that a
>single ground strap will cover everything. I will be using
>Polyphaser components on the shack coax end of things.
>
>Thanks for any and all advice.
>
>Don
>N0FGK
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