Horizontal Lines

Discussion in 'Legacy Models - Community Support' started by SkyMan, Feb 9, 2015.

  1. SkyMan

    SkyMan Standard User

    Joined:
    Nov 26, 2014
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    I have had these horizontal lines that occasionally appear ever since I had the camera. Most of the time they aren't there and would only show up maybe once every 3 months briefly and the go away. About a week and a half ago they should up and lasted for about a week. Right now the camera is working fine and the lines have gone again.

    I noticed while taking bias frames the lines would appear for in 3 or 4 frames and go away for the next 3 or 4 frames and then appear again. They seemed to cycle every couple 3 seconds. First I thought that maybe the fans or the cooler cycling caused them but I tried taking short darks with fans off, fans on, cooler off, cooler on but I couldn't get the lines to appear again.

    If you look closely at the lines they are not perfectly horizontal. They slope down from left to right slightly which makes me think it is noise from some where. Also the lines move down (vertically) from image to image. The are not in the same position on each frame.

    I reported this to David Morrow when he was still there but he didn't have a solution and the lines disappeared again.

    I have a snap shot of an image taken with CCD Ops that I have uploaded for inspection.

    Any ideas on what could be causing this.

    Bill
     

    Attached Files:

  2. Doug

    Doug Staff Member

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    Sep 25, 2014
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    Looks like some kind of noise or interference. It's noise that is at a steady frequency but not synchronous with the readout clocks - that is why the lines are sloping and move around.

    The question is whether this is coming from inside or outside of the camera. If from outside, the most likely cause is something on the DC power input that is noisy; for example, some dew heater systems have been known to produce a lot of power supply hash. So if you see the lines again, try switching off everything else that is electronic in the vicinity - if the lines disappear when you switch something off then it is probably the cause.

    How are you powering the camera? From AC power with the power supply, or from a 12V DC source?
     
  3. SkyMan

    SkyMan Standard User

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    Nov 26, 2014
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    I am using an AC powered power supply.
     
  4. Doug

    Doug Staff Member

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    If you see the lines again, please try turning off the other equipment you are using, one item at a time, and see if it goes away.
     

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