Quantex Video Adjustment

The Quantex Video system is old; you will notice this when you see it. You will likely be using the Shepherd Video Sytem to view the Centerfield video display. If you are using the Shepherd Autoguider to autoguide the telescope, then you will use the other Shepherd Video System (there are two) to view the guider field, and you will not need to learn about the Quantex.

If you are using the Tip-Tilt Autoguider, which provides the advantage of fast guiding and tip-tilt correction, you will use the Quantex system to view the guider field. This is a touchy business so go slowly:

1. Set the controls to the following values:

   VIDEO GAIN -- 4x (for Xybion, 10x for older cameras)

   SOURCE -- input

   FOCUS -- No function for Xybion, full CW - 10 deg for old cameras.

   BEAM -- No function for Xybion, full CCW for old cameras.

   SENSOR GAIN -- full CCW

2. Turn on both the HIGH and LOW DOME LIGHTS. Leave the mirror cover closed.

3. With the old cameras, slowly turn the BEAM control CW until the screen blooms (turns bright and then fades). A bit before the screen blooms you will see a little snow appear on the screen. Do this slowly since the bloom and fade are AC coupled.

4. Slowly turn the SENSOR GAIN CW until you see the hexagon pattern (approximately 30mm from flat to flat) on the guider TV.

5. With the old cameras, fine adjust the BEAM to get the best image.

   NOTE: Up to this point the TV is directly hooked to the camera's output, there is no digital processing so don't worry about the FRAME COUNT (smoothing) and FRAMES (integration) settings.

6. Set the controls as follows

   FRAMES 1

   FRAME COUNT 1

   Don't change any of the other controls.

7. Set the SOURCE to MEM. You are now seeing a digital version of the image.

8. Press both the input and mem buttons at the same time. The image will flicker bright and dark at about a 2 Hz rate. Adjust the BLACK LEVEL and the WHITE LEVEL to reduce the flicker as much as possible.

9. Set the SOURCE to mem.

10. You now can set FRAMES and FRAME COUNT to higher values. In the summer you will only be able to integrate (FRAME) two or three frames. In the winter when its cold you can get to ten or eleven frames.

11. A large number of smoothing frames (FRAME COUNT) slows down the image update too much and causes the guider problems. Don't go much beyond two or three on FRAME COUNT.

The guider should now be ready for use. Consult the Offset Guider Introduction and Observing Tutorial chapters for instructions on using the guider to assist in making observations.