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[Towertalk] Box forSPG and Lightning protectors

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Subject: [Towertalk] Box forSPG and Lightning protectors
From: (Ronald KA4INM Youvan)
Date: Sat, 21 Sep 2002 22:40:29 -0400
> thick cable. If there was a ground cable ruunning to the top of the
> tower, I was not able to see it from outside the fence.

   Steel is a very poor electrical and thermal conductor, but there is
enough of it in the legs of a 6' or more, faced tower to make any additional
conductor un-necessary.

> There are some curious doodads installed on the guys. A clamp
> around the cable and a colinear pair of cylinders about 10" long,
> parallel to the cable, and a tad more than the cable diameter away.
> The cylinders have rounded ends and show evidence of arcing.

   These are "stock bridge dampers' they are the mechanical equivalent
of an antenna tuner, reflecting energy (of a particular frequency) back
up the cable when the cable is vibrated, based on the distance from the
cable end, the thickness of the guy cable and the weight of the lead
weights.  Or if you prefer:
They change the impedance of the anchor end of the cable.
They dampen the high frequency vibrations, like a strummed string.
   The arc marks are most likely from "ball lightning" rolling down the
guy wires during fierce thunder storms and hitting the dampers, a good
reason to mount the dampers under the cable, although I don't think
many dampers are harmed by lightning.  (usually the short cable
the lead is molded on to rusts out and they fall to the ground)
There is a 50% chance there are more dampers on the cables at about
the same distance from the tower.

        73 (= Best Regards) de: Ron
     100% LINUX, since July, 1997   SENT Time and Date are UTC
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