Some odd RA issues?


Mike Shade
 

Here is the scenario:  AP1600GTO permanent in observatory with CP4 controller, Planewave CDK17, Optec Gemini focuser-rotator/SBIG STL6303E camera, unbinned resolution .64"/pixel.  Running Maxim 5.18 and ACP.  So far so good.  Now here is where it gets curious.  As I am in SE AZ, had to shut down for monsoon from early July to middle of September.  All electronics were unplugged, I do not suspect lightning damage.  Prior to shutdown in July this system returned round stars across the frame in 10-minute subs, guided.

 

After starting up again in September, noticed that the stars were ever so slightly off in RA, maybe a pixel or two, just enough to be not quite round, again in RA only.  However, images in RA last night showed several frames where there were actually double stars.  Looking at the guider log showed some pretty good jumps in RA.  The guider calibrates just fine with a 40+/ pixel move, and I have been able to do a 5-minute unguided with round stars after startup in September.  Of course checked primary mirror spacing, collimation, if everything is snug, cable drag and so on.  I have remeshed the gears and redone PEC, issues persists.  This is a random issue.  The Maxim guider log shows some hefty jumps in RA but NOT in DEC.

 

It is curious that prior to shutdown it worked like a champ...now...some issues with a number of images that are just out of round enough as to be useless, in RA.  It is always in RA.  I have looked for rodent damage, none.

 

I am suspecting something with guiding, easiest is weird guider cable, maybe the guider plug on the camera.  Anyone else seen this or have thoughts?  I know this is about as broad as "gee doc, I have a headache"...could be anything.

 

AP driver number is 5.09.07.

 

 

 

 

Mike J. Shade: mshade@q.com

Mike J. Shade Photography:

mshadephotography.com

 

In War: Resolution

In Defeat: Defiance

In Victory: Magnanimity

In Peace: Goodwill

Sir Winston Churchill

Already, in the gathering dusk, a few of the stars are turning on their lights.

Vega, the brightest one, is now dropping towards the west.  Can it be half

a year since I watched her April rising in the east?  Low in the southwest

Antares blinks a sad farwell to fall...

Leslie Peltier, Starlight Nights

 

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