I currently have 5 1032 rotors installed in Illinois and I've had numerous
failures. I've lost a number of potentiometers due to lightning strikes and
I've also experienced many failures when the weather gets just below
freezing. QRZ.com says you are located in Massachusetts - did the problem
occur when the temperature was below 32 degrees? I believe water gets into
the potentiometer and when it freezes the wiper does not make a good
connection. I spent great efforts sealing the units as well as possible
using silicone calk and rubber washers around the shafts. Personally I
think it would work better if the motor unit were upside down and water
could not get inside, however every motor design has been with the shaft
sticking up. At one point I got so frustrated that also installed small
silicone heaters inside several motors that automatically keep the motor
temperature above freezing. In all of my cases the readings were not
erratic, they were just dead and the rotator would not turn. The original
Clarostat potentiometers were really suitable to moisture problems and the
newer Bourns and ETI ones are much better. None are really waterproof. At
one time I asked Carl for a waterproof one and he did find an oil filled
one, but I'm not sure if it would fit and as I recall it was pretty pricey.
The newer motors also use a trailer type plug on the motor. I do not use
these and perhaps it may be a source of your problem. Last winter, during
the ARRL DX CW contest I thought I had a pot go bad, but later discovered an
animal had chewed through my control wire. If I were you, I would check the
trailer plug and take the motor assembly down, replace the potentiometer and
try to seal it better. The potentiometers do not have a sealed shaft and
moisture will get in. Lately, TIC puts a felt washer on the shaft to absorb
moisture. I've been using a large rubber one for a very long time, hoping
that any liquid will drip around the pot. TIC also started putting
capacitors on the potentiometers thinking RF was burning them up. I'm my
case, I don't think RF was ever a problem and I have not used that approach.
Perhaps if you're shunt feeding your tower it may help.
73,
John KK9A / P40A
To: TowerTalk Post <towertalk@contesting.com>,CQ-Contest Post
<cq-contest@contesting.com>, YCCC <yccc@yccc.org>
Subject: [CQ-Contest] TIC Ring Potentiometer Failure?
From: Jim Idelson <k1ir@designet.com>
Date: Sun, 28 Nov 2004 00:24:34 -0500
List-post: <mailto:cq-contest@contesting.com>
Hi all,
Not far into the contest this weekend, we began to have trouble with the TIC
1022E [a 2003 unit]. It exhibits erratic readout and rotation behavior. The
load is an Optibeam 4-el 40m yagi. I recently tightened the drive motor to
eliminate slippage of the ring gear. I suspect something has happened to the
potentiometer that feeds back rotor position back to the controller. A
search
of the towertalk archives shows that there have been problems like this in
the
past [1996/1997]. I went up the tower to have a look this afternoon, but did
not see enything suspicious. There were no bad external wiring connections,
etc. I sprayed the drive shaft and what looks like the position pot shaft
with
contact cleaner from the outside. That did nothing, but I suspect I would
have
to disassemble the motor to get the spray into the right places.
Any suggestions?
Thanks,
Jim Idelson K1IR
email k1ir at designet.com
web http://www.designet.com/k1ir
_______________________________________________
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Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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