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Old 08-09-2008, 12:10 PM
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erick (Eric)

erick is offline
Join Date: Dec 2006
Location: Shoalhaven Heads
Posts: 8,479
Argo Navis - if you're happy and you know it clap your hands...

Got my AN working last Friday night. Been waiting for what seems like ages for the opportunity.

I had refitted the encoders to the 12", and done the daytime encoder testing. I had experimented with the OTA on a nice flat concrete driveway to see what vertical angle it would get to. Less than 90 deg - hmmm. OK, remove the big rubber bumper I had put in place and discovered that the good Dr Tannehill had carefully placed a felt bumper so the tube stopped bang on 90 deg! So I could move ahead with MODE FIX ALT REF and test the alt encoder sense. Do you think I could get a clear night so I could do a two star align to test out az encoder sense! Tried to do it one night, peering into sucker holes. NOTE TO SELF - don't misidentify stars for alignment - the outcome is not pretty!

So last Friday night at Snake Valley, clear beckoning skies, dob plonked down on the grass (well on my half bricks) so probably not particularly level (I didn't check - I will next time), MODE FIX ALT REF'd on +90 deg with auto adjust on, and away I went to align on Antares and Archenar with a 12mm illuminated reticule eyepeice, then off to check az encoder sense.

This isn't working?? OK, switch to MODE RA DEC to see what was happening. OK, it helps if you plug the alt encoder in! I have to remove and reinstall the Alt encoder for each packup/stepup.

OK, back to az encoder sense. OK, I can see clearly what is happening - reverse it and try FIX ALT REF and ALIGN STAR again. Hey this all looks right! Dialed in MODE IDENTIFY, pointed at the brightest object in the sky after the Moon - look, I've found Jupiter. I didn't do any more with the alignment, but just started to tour around between fog banks rolling in and out. Pointing was not too bad (I stuck with objects that were readily visible), coming up in my 30mm eyepiece FOV was no problem. Somewhere in the middle, I worked out how to tweak the pointing arrow direction in az around the right way. I could easily move the scope to 0.0 and 0.0 in alt and az and stop there while I inspected the view for the object.

AN unit was dripping with dew but didn't miss a beat. I still have lots to learn since it intelligently keeps track of what you have done to allow returning to tours etc. which confused me at times.

But a tour of globular clusters in Tucana brought up NGC 121 which I hadn't seen before. Not surprising given NGC 104 (47 Tuc) is so close, it's hard to look elsewhere in the field of view!

So this is great! Need to concentrate on having the base closer to level and then on performing a more accurate alignment. Then to learn (by doing) the AN's capability.

Very happy. Thanks to Gary and Mai for such a great bit of kit!
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