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[TowerTalk] Switching 450 ohm twinlead?

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Subject: [TowerTalk] Switching 450 ohm twinlead?
From: (L. B. Cebik)
Date: Sun, 8 Jun 1997 07:26:34 -0400 (EDT)
> > Jim, some of the commercial relay boxes claim the include a heating element 
> > to reduce moisture build up.  When opened up the heater is a
> 10 watt wire round resistor.
> 73, Larry L.
> wa0etc
Heating elements that "drive out" moisture only work when powered.  This
is dandy for commercial and military stations that are powered 24 hours a
day.  For ham installations that may be on for only short periods each
day, a special line may be needed to keep the heater going.  Maximum dew
usually occurs during periods of maximum human sleep.  Hence, the need to
resolve a conflict between the need for continuous power to the heater and
the urge to depower everything when not present at the station--with
attendant concerns about preventing this line from being an entry for
surges on the station power line to the other equipment (and household
electronics as well).  (No fair tapping the neighbor's power line for
heater current.)  Although this line sounds trivial (10 watts to a heater
that does not do any transmitting/receiving work), it deserves all the
care of any other line going to the antennas.



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