Re: DEC Crosstalk
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Typically, crosstalk occurs when the Dec axis is moved slightly during guiding, and this causes a corresponding Ra movement. It typically happens when the scope is pointed toward the meridian (sometimes from zenith to the pole). The wiping action of the Dec worm against the Dec worm wheel causes the wheel to lift slightly if the Dec bearings are not highly pre-loaded. The entire worm wheel and shaft will tilt slightly back and forth as the worm gear turns in the worm wheel teeth. It's caused by friction of the worm teeth against the worm gear. This slight tilting is in the direction of RA but cannot be seen as an RA shaft motion.
From: Brian Valente <bvalente@...>
Sent: Wed, May 12, 2021 3:05 pm
Subject: Re: [ap-gto] DEC Crosstalk
>>>I'm trying to get some idea/context for the issue of DEC crosstalk to the RA axis during tracking/guiding.
How does the orthagonality of your guiding calibration look? if it's not at 90 degrees, that would cause mirroring between the axis