STi and CCDops, calibration failed - relays deactivate themself

Discussion in 'General' started by Wilfrid Ouellet, Aug 3, 2015.

  1. Wilfrid Ouellet

    Wilfrid Ouellet Standard User

    Joined:
    May 6, 2015
    Messages:
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    Hello all,
    Last night my calibration failed. I am using the Sti on a Orion ED80T-CF piggyback onto a VRC10 from
    Mallicam mounted on G11 driven by the new Gemini 2.
    The first time I had the problem of failed calibration was during last winter at -25C. After looking
    at all my connection, switching all wires and even tried another Sti, I finally found the problem
    being a bad lubrification of my mount. I cleaned and use silicone grease (permatex) on the wormgears
    and finally got the famous X when doing the calibration. That solution lasted 5 months only.
    Unfortunetly last night my problem came back but worst this time. The results were as follow:

    Star Positions
    Initially:Star at pixel 213.11, 217.91 with brightness 7956
    +X Relay :Star at pixel 212.56, 217.60 with brightness 7580
    -X Relay :Star at pixel 211.70, 218.01 with brightness 9013
    +Y Relay :Star at pixel 211.88, 217.92 with brightness 9714
    -Y Relay :Star at pixel 212.39, 218.86 with brightness 4738
    Calibration Results
    +X Relay : Speed = 0.00 at 0 degrees
    -X Relay : Speed = 0.00 at 0 degrees
    +Y Relay : Speed = 0.00 at 0 degrees
    -Y Relay : Speed = 0.00 at 0 degrees


    All relays de-activate themself. We tried pointing differents parts of the sky. I even tried to
    guide with my ST8300M with another computer and differents cables and the results were the same. I
    really thing that I might have a problem with the mount or Gemini since all hardwares were changed
    except for the mount and the Gemini.
    I think sending back the mount and Gemini for check up by Losmandy. But before I would like to see
    if anyone have seen this problem before.
    Why are the relays deactivating themself?

    Wilfrid Ouellet, Rimouski, Canada.
     
  2. Doug

    Doug Staff Member

    Joined:
    Sep 25, 2014
    Messages:
    6,963
    The #1 cause of guiding problems is the cable; they can be damaged fairly easily. Try replacing it. Please note that telephone-style cables can be built in two orientations, but they'll only work one way.

    There's an old app note on our web site that is relevant: https://www.sbig.com/site/assets/files/18148/st-7-rc.pdf (Ignore the 9 pin connector details; you have the "phone cable" style.)
     
  3. Wilfrid Ouellet

    Wilfrid Ouellet Standard User

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    May 6, 2015
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    Tks Doug, but we did tried another cable. I will verify if the cable is truly ''phone cable'' and I will get back to you soon. I did looked at the pins to see if one of them was missing or bent but they were all aligned. Also we have tried also another USB cable (shorter) between camera and computer without success.
     
  4. Doug

    Doug Staff Member

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    Sep 25, 2014
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    The Gemini 2 most likely allows for ASCOM PulseGuide instead of the guider cable. That's an option if you use MaxIm DL or similar software.

    Please do make sure you're using the guider cable that came with the camera. If you're using a different cable then you must make sure that it's built in accordance with the instructions in the above application note. If not then it may be backwards and that won't work. (The cables can be built in two orientations.)
     
  5. Wilfrid Ouellet

    Wilfrid Ouellet Standard User

    Joined:
    May 6, 2015
    Messages:
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    The camera was in operation for about 5 months without problem. Calibration was excellent. The camera is still working very fine. It is only the calibration that stopped suddently a few days ago and impossible to guide since then.
     
  6. Doug

    Doug Staff Member

    Joined:
    Sep 25, 2014
    Messages:
    6,963
    Okay, still most likely to be the cable. Just make sure the replacement is built correctly or it won't work either.
     

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