[AZ-Observing] Re: Troubles on the Pole

PEC stands for "Periodic Error Correction".  This is used to correct for 
small imperfections in the worm/worm gear on the RA axis, which will 
repeat during each worm rotation.  The computer senses a point on the 
shaft to set the beginning of the worm shaft rotation.  The observer 
turns on PEC "training", and keeps an object centered (in a crosshair 
eyepiece) by pressing the tracking buttons during a full rotation cycle 
of the worm shaft.  The computer records the corrections, and then will 
apply them in the same pattern (when PEC is turned on).  If the observer 
is not satisifed with the result, he can reset the "training" and record 
a fresh pattern.  Since the errors repeat the same way for each worm 
shaft rotation, (typically about 2 to 4 minutes per rotation), the 
"training" can be used for any subsequent night.
I am unfamiliar with the so-called "cone" correction, but that may 
indeed be a way to compensate for non-orthoganality of the axes.  Read 
up on it and let us know.
(I am repeating this memo, as the stupid "net nanny" caught me with too 
many lines showing!!)
Gene Lucas (17250)
Jimmy Ray wrote:

>"There is software that will "model" the errors and compensate for them.  
>TPoint from Cyanogen is such a package." Would this be what "PEC" or "Cone" 
>correction does on the Celestron CGE's? Jimmy Ray
>
>  
>

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