I had six pots burn up before I found an alternative.
The burn was happening at one end of the pot, and not
on the wiper. Same place every time. I never could
figure out what was causing the problem. It looked
like a small fuse that opened up. I had MOV's and
large bypass caps on every lead, and it still happened.
I suspect the problem was in the control box, which is
now in the junk box. I finally got sick of replacing the
pots every 3 months. My current fix has lasted 3 years so
far. Now I am using only one side of the pot and measuring
resistance with an ohmmeter. I have a calibration chart,
and it is repeatable to within +/- 3 degrees. Someday I'd
like to build meter shunts and use the old meter box to
indicate direction. Here is a picture of the control box:
http://www.k4ro.net/tcg/image/ticring/new_tic_box.jpg
The TIC-Owners reflector is still up and running, but
there hasn't been any traffic for about a year or so.
I've copied this post to see if any of the remaining
addresses are still valid. :-)
-Kirk K4RO
On Sun, Nov 28, 2004 at 12:35:52PM -0000, Barry wrote:
> Jim,
> Could be one of two things. In the earlier rotors, there was a
> suspected problem of RF burns on the pot coil. This seems to have
> been cured putting a few bypass caps on the pot. This was added to
> their production models 3-4 years ago, if I recall correctly.
>
> Another possibility, which has also happened to me, is water getting
> into the pot and rusting it inside. I don't recall all the details,
> but Carl at TIC made some changes to help prevent this as well. One
> thing I did in additionis drill a few small holes in the bottom of
> the motor box, for drainage. If water gets in, there's no way for it
> to get out. Now there is.
>
> The only solution is replacing the pot. There is (was?) an informal
> TIC reflector run by K4RO. I don't know if any archives are
> available, but this problem was discussed in the past, so you may
> want to contact him.
>
> My TIC rings worked fine this weekend. However, my T2X froze up
> pointing west (40m Yagi and top TH7) on Saturday afternoon, when I
> was ready to move from working some JAs and Pac on 15m, back to 40m
> to work EU. So much for this contest :.(
>
> 73,
> Barry W2UP
>
>
>
> On 28 Nov 2004 Jim Idelson wrote:
>
> > 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
>
> --
> Barry Kutner, W2UP Internet: w2up@mindspring.com
> Newtown, PA Frankford Radio Club
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