[TowerTalk] Lightning Protection Question

[john at kk9a.com]

Earlier this year I buried a lot of Heliax and rotator wires in a 250 foot 
long trench going from my tower base to the house.  The wires were not 
connected at either end and were not touching the tower and shortly after 
burying them my tower was struck by lightning.  I saw burn marks on the ends 
of the buried wires and on the Heliax connectors so voltage can definitely 
be induced into nearby conductors.  As Jim said the best place for the 
protector is at the entry panel to the shack.   I wonder if it does any harm 
to also have them at the tower base?

John KK9A



To: "towertalk at contesting.com" <towertalk at contesting.com>
Subject: Re: [TowerTalk] Lightning Protection Question
From: "Jim Brown" <jim at audiosystemsgroup.com>
Date: Sat, 11 Sep 2010 08:53:25 -0700


I disagree (and agree with K1TTT) -- lightning protection devices are
protecting you radios by short the voltage on the center conductor to
the shield. They cannot do that at the tower -- voltage can be induced
on the coax between the tower and the shack, and a protector at the
tower is too far away to offer much protection at RF. The best place for
them is at the entry  panel to the shack.

The SHIELDS of coax SHOULD be bonded at top and bottom of the tower.

73, Jim K9YC