Tech Help

TROUBLESHOOTING CAMERA TUBES!

The camera tube has many ways of going bad and many things can effect the image quality of your imaging system. Some problems can be fixed without replacing the camera tube. Below is a list of problems and possible cause.

 

ARCING:

  • Check to see that the tube base is dry and is making good contact.

  • If tube is gassy or short circuited, you will need to replace.

BLEMISHES/ARTIFACTS ON PICTURES:

  • Check for dirt and/or dust on face plate of camera tube as well as all lens and the II’s output face.

  • If there are blemishes on camera tube target, it must be replaced.

 WHITE SHADING:

  • Check for non uniform target sensitivity.

  • Check adjustment of tube beam alignment.

  • If not uniform, replace tube.

 BLACK SHADING:

  • If you have a black shading adjustment, adjust to correct. Also check to see if your beam is +6db over peak white signal level.

  • Check adjustment of tube beam alignment.

LAG STICKY OR IMAGE RETENTION:

  • Check target and cathode voltage, beam current and alignment. If it uses a light bias lamp, check for correct operation.

  • If cathode has low emission, or target material has deteriorated, replace tube.

 

LOW, DIPPED OR INSUFFICIENT BEAM:

  • Check heater supply voltage, grid 1and grid 2 voltage.

  • If cathode has low emission, or if tube is gassy, replace tube.

 LOW RESOLUTION:

  • Check for focus, yoke alignment, grid 3 or focus current and lens focus. Maximize both the electrical and mechanical focus.

  • If cathode has low emission or target material has deteriorated, replace tube.

MICROPHONICS:

  • Check yoke alignment, tube clamp & socket.

  • Replace tube if mounting is found to be loose or unstable

SPLIT BEAM:

  • Check heater supply voltage.

  • Check beam (G1) voltage setting.

  • If cathode has low emission or tube is gassy, replace tube.

R. F. NOISE:

  • Check all grounds and for a high R.F. field that is too close to tube.

  • Check for loose target connections

MOIRE PATTERN:

  • Check grid 3 voltage or focus current and for tube orientation in yoke.