USALS Homing

[dennise]

I use a Pansat 3500SD turning a Fortec 90cm dish with a Stab HH100 motor. This setup works fine but I have a question.

Does anyone know if USALS uses feedback to home in on a satellite?

When directed to a satellite, I have seen my dish approach a satellite position and then slew slightly east-to-west back and forth for a few seconds before stopping; at which point I get good signal quality. This implies there is some kind of feedback loop that USALS, running on my 3500, uses to slew my dish back and forth until the quality is at a maximum. Is this really how USALS works or alternately, does USALS just calculate a new position and then directly slew the motor to that position without any feedback?

So which is it ... closed loop with feedback?
or
open loop with no feedback?

Just wondering if anyone knows

[rainman]

check out this it's got some good info on usals.
Fortec Star Mercury II Video Learning Series

[Vitruvius]

I have had this question before, but I was told no. These motors just do the math to move to the correct location based on your Lat and Long...

I suppose if you wanted to test your theory you could change your lat and long by 5 degrees or so and see if the motor hones in on the satellite.

Some computer programmer should develop this idea and somehow I am sure it could be done.

[Larry Acklin]

My old C band receivers did the back/forth thing when autotuning during setup. Both E/W position and skew were tweeked. Most of the time it worked well.

After setup was exited, they just drove to the position.

Your motor likely is closed loop positioning internally, and the hunting you see is indicating the micro is overdriving the position, or there is some slop in the gear train.

Larry

[disneyjoe7]

I found it interesting that the dish would move east then west then back to original position if dish reception was blocked. Making me think there's some feedback system in play with the Traxis DVB 3500 receiver.

[Muad'Dib]

I found it interesting that the dish would move east then west then back to original position if dish reception was blocked. Making me think there's some feedback system in play with the Traxis DVB 3500 receiver.

Did you mean TRIAX??

[disneyjoe7]

Did you mean TRIAX??

No Traxis is what I meant.

edit: link removed per RULES