Mach2 keypad tests

Roland Christen

Hello Astronuts,

Finally had a night of clear skies where i could test the Mach2 with my 160EDF scope. I am finalizing some new features in the keypad which include tracking limits that were recently requested, pointing modeling, unguided imaging and other neat features. We are finishing up the new software an hope to have keypads ready for customers very shortly for all CP4 and CP5 controllers.

I would like to share some results from last night:
The setup was my 160 EDF scope with a QSI 683 camera. I started the session while the sun was still up and ran a simple pointing model using stars from first to about 4th magnitude with an H-a filter and .05 sec exposures. I was able to center the stars manually on the crosshairs via the keypad, using MaximDL imaging software. I started with the scope under the mount with stars in the east along a constant Dec line that the object is on. The object is a group of galaxies called the Eyes, part of Markarian's Chain. The Mach2 allows you to place the scope under the mount if it can clear the tripod, so you can image all night long without flipping. It also has dual high res encoders that eliminate all periodic error and can be driven in both axes, very smoothly, at custom rates.

I centered 8 stars along the Dec line and entered them in the mount model memory. I purposely misaligned the pole to see how well the model would work for quick eyeball PA such as you would get if you set up in the field and are a bit lazy (like I am usually). I'm guessing that my PA is off by about 1/4 deg or more based on the amount of drift I was getting.

Is it possible to get round stars, being not polar aligned and not guiding, but simply relying on doing a quicky model? And not a full all-sky model with umpteen terms, but just 8 points? That's what I aimed to find out.

So, here is the setup: 160EDF, Mach2 mount, QSI 683 CCD camera, light weight Losmandy tripod, laptop with SkyX and MaximDL. The keypad routine is simple - click on a star in SkyX and slew to it, center it in the image in MaximDL, then press Enter on the keypad. Go to next star and repeat. Takes a few minutes each and probably could be automated, but for 8 stars it's not a biggy for hands-on operation.
TBD in next post

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