[amsat-bb] Re: KCT Problem

[Alan P. Biddle]

Dave,

It has been at least that long since I have had a KCT.  However, there are a
couple of things external to the KCT which could give you a stalled error.
One is a loss of the azimuth reference signal.  I dimly recall a test
program which would let you read the ADC data.  If so, see if both the
azimuth and elevation are indicating correctly.  If not, check the signal at
the back for the rotator box, and at the DB-25 connector to the KCT.  I
would think that you would see the rotator run away in one direction or
another, however.  The other case is if there is a problem with the
left/right controls.  You should be able to check that at the same points by
grounding the appropriate lines manually.  Perhaps a solder connection has
opened up.  In any case, you can check this easily with a VOM and a jumper
wire in a few minutes.

If all that is working, then the KCT or software is the culprit.  As I
recall, there were not many chips there, so it may be possible to fix by
substitution.  It will, probably, be either an ADC chip or the control
driver chips.

I hope this will help a bit.  I did the above exercise a couple of times,
and both times found a bad connection in my work.  With luck, somebody using
the unit will have some more specific suggestions, and possibly the specific
pinouts and chips.

Alan
WA4SCA