View Single Post
Old 08-09-2008, 12:56 PM
Registered User

gary is offline
Join Date: Apr 2005
Location: Mt. Kuring-Gai
Posts: 5,437
Thumbs up Thank you

Originally Posted by erick View Post
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.
Hi Eric,

Thanks for the post and great to hear you are up and going.

Now that you have established the encoder direction sense signs, we recommend
you now start using AUTO ADJUST ON. This then makes setting the ALT
REF point at 90 degrees not so critical, as it will refine it for you based on
your two star alignment.

To set it up, DIAL up MODE SETUP, SETUP ALT REF and enter +090.000.

Then when you perform the FIX ALT REF STEP, use ALT REF=+090.000 AUTO

Perform your two star alignment as normal. The WARP factor should then
be 0.00 (A) where the (A) indicates the ALT REF point was automatically
adjusted. If you see a non-zero WARP factor when AUTO ADJUST is ON or an
(X) instead of an (A), it means something is amiss, such as a
misidentified star or cable not plugged in. Keep in mind that though a
WARP factor of 0.00 is a prerequisite for good pointing performance, it
does not necessarily guarantee good performance. The reason is that the
AUTO ADJUST mechanism bends over backwards to correct the ALT REF point
so as to produce a WARP factor of zero wherever possible, even if you
have misidentified the alignment stars.

If you are curious, push the OTA back to the vertical stop and DIAL up
MODE ENCODER after you have performed the two star alignment. The right
hand displayed value is what AUTO ADJUST calculated your reference point
to be.

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.
You may have come across the MODE SETUP, SETUP GUIDE MODE menus.
These allow you to reverse the sense of the arrows to suit your preferences
and are independent of the encoder direction sense signs. You might also

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.
Say you are in the middle of a TOUR and then decide to view some other
object that is not going to be in the TOUR. Press EXIT, use MODE CATALOG or
MODE IDENTIFY to go to your new object. When you wish to return to
MODE TOUR, press ENTER and the word FIND will be flashing. Spin the DIAL
one click and it will change to REJOIN LAST TOUR. Press ENTER. You have
now rejoined your tour at the point you previously left.

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!
This is the type of story we like to hear.

Very happy. Thanks to Gary and Mai for such a great bit of kit!
Thanks Eric. We appreciate your kind comments and hope that you have many
great nights ahead.

Best Regards

Gary Kopff
Managing Director
Wildcard Innovations Pty. Ltd.
20 Kilmory Place, Mount Kuring-Gai
NSW. 2080. Australia
Phone +61-2-9457-9049
Fax +61-2-9457-9593

Last edited by gary; 09-09-2008 at 12:01 AM.
Reply With Quote