[TowerTalk] RE: TIC Ring Potentiometer Failure?

[David J Rodman MD]

I have 8 rings and have experienced many many failures of various items 
over the last 12 years.  The potentiometers tend to last a few years 
then start to have eratic feedback problems, in my experience.  There is 
not too much you can do with a component designed for indoor use placed 
outside for long periods of time.  I have never had a pot fail from RF 
or lightning (as far as I recall), but I have heard of it too.  A failed 
or dirty pot could be particularly bothersome if you are using digital 
controllers.  I have analog controllers as backup in switchable parallel 
with my digital controllers.  So if the pot gets dirty and it is 
daylight, I just keep my hands on the control and observe the antenna to 
advance the ring while the pot jumps like crazy.  I have heard of people 
trying to replace the potentiometers on the tower after various 
failures.  Personally, I do not recommend that.  Even getting a motor 
off can be tedious by the time one plays with frozen bolts, wire 
terminations, dropped tools, bad weather, bees and general bad luck.  
Working with a small part like this is not what I like doing at 140' in 
the air.  Because of my share of bad luck with TIC products,  I keep 
four spare motors with electronics and two slaves at all times.  If the 
motor fails, or gives me trouble I plan to exchange it and look at 
rebuilding it at a later time.  I have lots of spare parts and Carl has 
been particularly gracious and helpful sending me needed items for my 
"stock".  I have only experience with the first and third generation 
motors.  At this time, I am replacing my older series of motors with the 
new generation in hopes they will be more reliable.  Unfortunately, I 
had two new motors fail two days before CQWW.  They were brand new in 
October.  I also had to do a ring repair Saturday of CQWW.  Damage was 
left over when a cradle broke on my 40m yagi last winter.  That was my 
contest.  I worked VU2WAP and the ring froze at 260 degrees due to a 
slipped motor which did not give contact with the ring.  I blame the 
installer for not recognizing the problem.  The ring was bent and 
separating under the antenna.  Seven hours at 140' in two trips while 
the contest slipped by is not my idea of having fun.  Barry, you were 
not the only one with a rotor malfunction during CQWW.  I still think 
swapping out your motor is the best idea.  Be sure you have someone on 
the ground to match the antenna for calibration to the motor when the 
new one goes in place.  Don't assume the replacement and the old one 
will match perfectly.  I found out the hard way that "calibration" is 
not always guaranteed and had to reclimb at least once or twice to fix 
things well in the air.  You might consider jumpering the ring to keep 
it moving and visually stop it when necessary until you get it back to 
normal.  I don't think moving the pot will clean it up significantly.  
Hopefully, you are a "daylight DXer" or the tower is close enough to 
watch in the dark.  I hope you have luck with this and parts are easy to 
find and replace.  Good luck.