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[TenTec] Aux Antenna

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Subject: [TenTec] Aux Antenna
From: rohre@arlut.utexas.edu (rohre)
Date: 16 Sep 1998 14:24:49 -0500
Hi,
Scott makes a good point about external protection for the antenna inputs to
not only the same rig, but other rigs in the typical shack.

Storms with lightning approaching are not the only source of static buildup. 
Wind blown snow storms with low humidity air, and dust blowing in desert areas
can build up significant voltages on the antenna. Desert or Great Plains winds
are significant sources of voltage buildup.

An SOP for either transmitting or receive antennas that can bleed off this
static charge is to use gas tubes to ground, or even to have high value
resistors to ground, such as 100K ohm, which will not bleed much power either
transmitting or receive from the rig, but which will keep the voltage from
static buildup in a blowing wind condition from incrementing the voltage
developed over the antenna.  There will be a constant discharge path for the
static through resistors, while a gas tube must fire at some threshold voltage
frequently 60 volts or more.

Another good use for 100K ohm across the center of dipole, is if something
happens to break the feedline from the dipole at the center, you can tell by
no longer being able to measure 100k ohm across the feed line end in the
shack.

73, Stuart K5KVH

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