"Jeff" wrote in message
. com...

snip

The system works unitil it gets out of sync for some reason. A leaf
obscuring a sensor, a bird sitting on it etc etc.
One the rotator gets ahead of itself it will never find the sun.

This is true.Perhaps multiple sensors to some OR gates would provide the
necessary redundancy. I provided only one fail-safe mechanism and that is
for a cloud.

snip

The actual system will depend on what type of rotator you are using, a
stepper motor would be the easiest since you know how many degrees each
step
is. If you are using an 'normal' antenna' rotator then most have a
feedback
pot, and a control pot. All you have to do is apply a voltage in place of
the control pot to get your desired position. There are many ways of doing
that from a computer, a micro controller, a counter chip feeding a d/a
converter. a series of relays switching in resistors, the list is almost
endless.

What, no hamsters? :-)

Seriously, OP "JERD" never said whether he wanted a complicated, highly
accurate setup or just something that works. I went for bare-bones, basic
El Cheapo, the most fun, IMHO.

(I have more of a history of jury rigging antenna rotators than most people.
My first [1968] was the building of a controller based on two doorbell
pushbuttons from the hardware store; I bought the correct transformer and
capacitor from the electronics store. No indicator ... We aimed it solely
by looking at the TV. The components were screwed down to a chunk of
plywood I found in the yard. Oy! But I was a young sailor living in town
on my own dime for the first time. After rent and utilities, there was beer
money and not much else.)

73
"Sal"