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CCD camera will pick it up to give you oval stars - that is a given. What you need to find out is whether this periodic error
is within limits (± 3.5 arcseconds for the 900GTO and 1100GTO and ± 2.5 arcseconds for the 1200GTO and 1600GTO)
and whether it is smoothly varying. You can also do some hand guiding using the 4 buttons on the keypad. It will tell you
how responsive the mount is to your guiding inputs and may even show some hidden problems when you try to keep the
star on the crosshairs.
Alternately, you can use
PEMPro™
(The full version of
PEMPro™
is included with the 1100GTO) to characterize your
periodic error. It will tell you things like the peak value and the smoothness of the error.
You can also characterize your mount tracking and guiding abilities using the “Characterizing the Dec. Motions” test
outlined in the Technical Support section of our AP website and included in the back of this manual. Many times a problem
guiding in R.A. can be the result of a Dec. axis mechanical problem. Not knowing this, you will be forever chasing down
the problem on the R.A. axis, and never reaching a solution. Characterizing your Dec. Axis will at least show you that the
mount reacts properly to the 4 guide directions. If it shows a problem area, then at least we will know how to fix it.
Once you know that the mount is tracking in a normal fashion with normal periodic error profile, you can go from there to
begin setting up your guiding parameters. It is not a piece of cake to get an autoguider to work flawlessly. It is an art, but
once you know that the mount responds properly to the guide inputs, it should be possible to set it up to work accurately.
Additional Support
For additional information regarding the 1100GTO, refer to the Technical Support Section of our website. We also
encourage you to participate in the ap-gto Yahoo user group. The members of this group are very knowledgeable about
the operation of their mounts, CCD imaging and other related issues. The staff of Astro-Physics also participates and you
will find a wealth of information in the archives. To find the group, link from User Groups in our website’s sidebar.
If any problems occur, please don’t hesitate to contact Astro-Physics for assistance.
We encourage you to submit your technical support questions directly to Astro-Physics by phone or e-mail:
We may add additional troubleshooting tips to future versions of this manual or in a separate technical document. In such
an instance, we would add this information to the Technical Support section of our website as well.
ASTRO-PHYSICS, INC
11250 Forest Hills Road
Machesney Park, IL 61115
Telephone: (815)-282-1513
Fax: (815)-282-9847
www.astro-physics.com