March 2010

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DSI/MDL Autoguiding Calibration and Halting, and Loss of Telescope Tracking



First Variable Data / FITS Header / MaxPoint Trial

Imaged BG Gem at 9:05 PM DST (1:05:15 2010-03-25 UT). Pinpoint operational. Tested writing values to FITS header. Downloaded, installed, configured, and did Auto Calibration of MaxPoint.  Had to figure out the exposure. First 12-star run only found 2 stars.  Lengthened exposure time to 15 seconds and binned the CCD to 3. MaxPoint is a really excellent program.  The Maxpoint telescope pointing errors and observation errors are shown below.


Start-up / Shut Down Procedures

Wrote a simple checklist to start-up and shut down all scope, dome, instrument hardware and software.

MaxmDL Licence / Plate Scale

Entered the MaxIm DL licence as received via e-mail form Cyanogen.

Calculated and verified plate scale using AIP4WIN, ALADIN, ECU, and MaxIm DL

Focal length: 2830 mm
Plate Scale: 0.64"/pixel
FOV: 16.5' x 11.0'

2nd RS-232 Connection / Dew heater Cable Management

On Tuesday the 16th, I picked up a second 9-pin gender changer and two DB-9 to RJ modular adapters.  I think these are for RJ-45 but the RJ-11 plugs work in them as well.

New AP Driver

After googling the web and posting messages to the ECU and Mathis Users Yahoo Groups, I finally found a reference to a new ASCOM AP driver written by Ray Gralak.  It is AP V2 (v4.99.58) and has been out since July 2009 (v4.99.9).

I don't know why this isn't posted to or why it wasn't supplied with the Mathis-supplied PulseGuide CD which had ASCOM and the old AP v4.1.25 driver on it.  Very frustrating.

Telescope Connection Problems

Last night (2010-03-18) I noticed that the telescope position cursor would jump to random locations across the planetarium sky display (ECU).  Since the dome is slaved to the telescope position, the dome would try to keep up with the randomly reported positions.  Through all this, the telescope was tracking and was not slewing. The same issue repeated tonight ans it appears after a few hours of use.  I am suspecting that threre must be an issue with the AP driver (V4.1.25) by Ajai Sehgal.

Polar Altitude Adjustment, AutoFocus, DSI Off-axis Guiding, Imaging Test

I began the night by adjusting the polar axis altitude by drift aligning on a star near the eastern horizon.  There were a few back and forth initerations before I figured out which way to turn the altitude screw on the polar base.

After a little head-scratching, I figured out how to configure FocusMax (FM) with RoboFocus (RF) on the Van Slyke (VSI) OMG5.  The initial First Light Wizard attempts in FM ended quickly in failure.

Final Orthogonality Adjustment and Polar Drift Align

Made up two DB-9 to RJ-11 modular connectors to connect to 2nd RS-232 port on A-P control box.  Will use it to connect with PulseGuide.

Completed the orthogonality adjustment tonight.  About 1 minute of arc in error.

Completed polar alignment using drift align.

Chasing Orthogonality

Made up two brackets with adjustment screws.  The brackets are mounted in existing holes which bolt the plates to the rings. Now I have a fail-safe way to move the OTA assembly in the dovetail plates.

Spent a few hours (til 2 am) trying to achieve orthogonality, but forgot to correct for half of the error when sighting Polaris.  This resulted in "chasing" and over and undercorrecting for the error.