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2013_08_2021

Rig #2:  V1101 Aql

The heat has returned – but despite a full moon this is quite a nice evening.  Warm, humid, calm, really good seeing (maybe 1.7 arcseconds).  Low temp tonight only about 75.  High tomorrow 90.  Meridian crossing at 11:22pm tonight – so only good until about 1:30 when V1101 will begin to pass behind the maple tree.  Need a late-night target….

Rig #1: Down for Repairs

The declination motor assembly has been returned to Astro-Physics for repairs.  It appears the encoder and perhaps motor need replacing.  Another $500 repair.  So that $6500 AP1200?

  • Original cost of mount $6500
  • Upgrade to CP3 electronics $1050
  • New Piertop Plate from Dan’s $130
  • Three counterweights $725
  • Dovetail Clamp $165
  • 1612FSA $140
  • Replace RA motor and encoder: $600
  • Replace Dec encoder ( &Motor?)  ???

So far, not including whatever the current repair bill will be, total is $9310.  And to be honest I think the had controller is going to need replacement as the buttons on that don’t seem to always work as they should.  Woof!  That’s a ton of money for an 11-year old mount.  Clearly it’s time in Florida was not kind to it.

CLOUDS!  10:50pm, re-acquired target on other side of meridian at around 11:40pm.

CLOUDS AGAIN!  12:10am.  I’m done!

Maxim DL Troubles

There is just no single thing more annoying with Maxim DL than it’s inability to find and guide on an obvious bright star in the guider.  Setting aside other issues such as Maxim’s utter ignorance of half of the numerical universe (it does not recognize and truncates to zero any negative number) it just befuddles me that the program cannot find an obviously bright star in the field and guide on it.  Tonight gave me a clue, however, as to why it has troubles.  Because it was a full moon night and because the guider is fairly far off the optical axis there was a fairly strong gradient to the background.  It appears that this fools the guider into thinking it is looking for a really big star just off the edge of the guide box.  So it looks like one solution might be to fully calibrate the autoguider camera so that a flat field image can take that gradient out.  Still, if there was some way to limit the size of object the guide program was looking for that might be a quicker solution.  Something along the lines of DAOPhot’s star finding algorithm, using a “lowered gaussian” idea.  But then that means the user has to know the fwhm of stars as seen in the guide camera.  Anyway!