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Polar Alignment of CGEM

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#1 GeorgeNC

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Posted 12 June 2009 - 09:52 AM

Too many cloudy nights lately - need to gain some more experience with the new CGEM. Severe thundershowers about 5:00 pm yesterday, but after they passed through some patches of blue appearing. By sunset the skies were nearly clear and the CSC showed blue for the rest of the night.

Set up the CGEM in the side yard with the William Optics Flt110 refractor and Stellarvue guidescope. No problems with the usual 2 + 4 alignment, but some difficulty with the new polar alignment routine. Unsuccessful with the polar alignment on Kochab (guess it's too close to the celestial pole) and with Alkaid (too close to the meridian perhaps?), finally success with Eltamin.

Much prefer to use Polaris. Easy to make adjustments while looking through the eyepiece. Can't reach adjustment knobs while viewing in the eyepiece - have to lean over, make the adjustment and then look back in the eyepiece to see if it's centered.

Anyway, finally successful and had a good, albeit brief, night of imaging. Great tracking by this mount. Just as I got the autoguider calibrated and on target, heavy clouds moved in and shut me down after just a few subs.

#2 rmollise

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Posted 12 June 2009 - 01:22 PM

Too many cloudy nights lately - need to gain some more experience with the new CGEM. Severe thundershowers about 5:00 pm yesterday, but after they passed through some patches of blue appearing. By sunset the skies were nearly clear and the CSC showed blue for the rest of the night.

Set up the CGEM in the side yard with the William Optics Flt110 refractor and Stellarvue guidescope. No problems with the usual 2 + 4 alignment, but some difficulty with the new polar alignment routine. Unsuccessful with the polar alignment on Kochab (guess it's too close to the celestial pole) and with Alkaid (too close to the meridian perhaps?), finally success with Eltamin.

Much prefer to use Polaris. Easy to make adjustments while looking through the eyepiece. Can't reach adjustment knobs while viewing in the eyepiece - have to lean over, make the adjustment and then look back in the eyepiece to see if it's centered.

Anyway, finally successful and had a good, albeit brief, night of imaging. Great tracking by this mount. Just as I got the autoguider calibrated and on target, heavy clouds moved in and shut me down after just a few subs.


Hmmm...I've used the AllStar routine on Polaris, and it seemed to work fine...

#3 GeorgeNC

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Posted 12 June 2009 - 01:40 PM

Hmmm...I've used the AllStar routine on Polaris, and it seemed to work fine...


Interesting. When I tried to use Kochab and Alkaid, I got a message on the handset saying "No Response 17". I assumed that was its way of telling me not to use those stars. The CGEM manual says:

For best results choose a polar alignment star that is high in the sky and near the Meridian. Try to avoid stars that are close to the west/east horizon, directly overhead or too near the celestial pole.



Next time out I'll try Polaris and see what happens. Thanks for your reply.

#4 Patrick

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Posted 12 June 2009 - 03:12 PM

I got a message on the handset saying "No Response 17".



No Response Errors are not telling you that your alignment star choices are wrong. They're telling you about a mount problem. What kind of power source are you using?

Regarding the star you use for polar aligning, Polaris might work, but the more angular distance you are away from Polaris, the more accurate the alignment will be.

Patrick

#5 GeorgeNC

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Posted 12 June 2009 - 04:01 PM

What kind of power source are you using?



Hi Patrick, thanks for the input. That's a helpful link.

I'm using 110v household power with a converter to 13 volts DC. Been using it for a couple of years on the CG5, CGE and now this CGEM. Guess it could have been a loose connection, but after the two issues I described, I didn't have any more problems for the rest of the evening.

#6 GeorgeNC

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Posted 13 June 2009 - 11:32 AM

Thanks all for your comments. I went out last night - carefully checked the electrical connections and the connection of the hc to the mount and had no troubles at all. Used Kochab for polar alignment without a hitch. Had a great night of imaging with the new mount.

:jump:






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