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Re: Radio Shack rotators



No, APRStk simply uses time as the position feedback for working
with cheap TV rotators.  The rotors all run generally at 1 RPM, so 
6 deg is 1 second.  Thus APRStk needs no feedback.  Just 2 bits 
on a parallel port.  One closes the CW button and the other CCW.

Then software keeps track of where the antenna is pointing based
on run time.  It avoids any long term drift or inaccuracy because
these rotors all have a mechanical stop.  And many passes per
day will attempt to go through the south stop.    This provides
an automatic re-calibration to exactly 180.

Also, the software will sense if it has not hit the stop recently
and if it is within 45 deg of South and there is nothing in view,
then it will drive to south to force an auto-calibration.  Thus, 
it runs forever and never needs calibration, needs no pots,
just plug and play.

Also APRStk auto-tunes the D7 and D700 to each satellite
including doppler.

NOTICE:  This system is not for precise AZ/EL control of an
OSCAR class array.  It is meant for single TV rotator AZ
control with a -modest- beam titled up at about 10 to 15
deg.  That is perfect for all LEO satellites.

APRStk is an old DOS program and so I am not pushing it.
But I do wish all other tracking programs would incorporate
this simple algorithm so that most people interested only
in the LEO's could use simple $60 rotators for satellite work.

de Wb4APR, Bob
>>> Jim Jerzycke <kq6ea@pacbell.net> 07/11/06 11:18 PM >>>
Doesn't Bob's little wonder use the FODTrack protocol?
Jim  KQ6EA

--- "Robert C. Rice" <rcrice@speakeasy.net> wrote:

> At a hamfest last weekend I picked up a RS rotator
> (model 15-1245) for 
> not much more than lunch money.
> 
> Now the question is whether I can put it to use in
> an automated way 
> under Nova.
> 
> Bob Bruniga wrote a nice little article on
> controlling this rotator 
> under his APRS program.
> 
> Is anyone aware of an easy method to have Nova drive
> one of these for 
> automated pointing at LEOs?
> 
> Robert
> WB5PKN
> ----
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----
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