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The TV control box is at present in Bay 1 of the telescope control console. There are two monitors associated with the TV. The first is the 'raw video' monitor which is on top of the control console and secondly there is the all-singing, all-dancing Grinnell monitor which is incorporated into the control console to the left of the main GD4K display. Below the Grinnell monitor is an array of feature-selection buttons. These are described in detail in Section 6.4. The final piece of hardware in the TV system is a joystick controller box which normally resides on the telescope control console desk - or nearby.

Nowadays the TV Camera is mostly used with the CCD Camera. Typing TV at the instrumentation computer will bring the TV flat in, in about seven seconds. Similarly it can be removed by typing CCD. The TV flat's position can be seen on the MIMIC display.

Another use for the TV Camera is with the People's Photometer where it is mounted so as to view the rear of the Photometer apertures. Different aperture plates can be mounted and selected under pneumatic control from the instrumentation computer in about a second. It is usual to leave one aperture plate position empty so that the TV can view a field of about 3x4 arcmins for acquisition.

The TV can also be used with the old A & G Box, now mostly confined to the Richardson-Brealey spectrograph. The old A & G box control box is available at the desk. Only two of the illuminated double-action switches are relevant to the operation of the TV. The first from the left on the top row ACQN/COMP MIRROR (IN/OUT) is used to move the flat mirror into or out of the beam. The movement takes approximately 15 secs each way. Successful parking of the mirror is indicated by the ACQN/COMP switch which illuminates either IN or OUT. While the mirror is in motion, the adjacent PROBE MOVING switch will illuminate.

To operate the system follow these steps:

  1. Make sure all lights are out in the dome.
  2. Turn on the power to the two monitors of the TV system and let them warm up, so that you can see if any image is on the TV camera.
  3. Ensure that the gain control of the TV control box is turned fully off (turn anti-clockwise until it clicks).
  4. Press the black ON power button on the control box. The two lights labelled DELAY & RESET will come on. Wait (about 15 secs) until they go out and the green ON light comes on. If RESET does not go out, press OFF, check step (3) and try again. If these lights are still reluctant to go off a gentle anti-clockwise turn on the gain control switch will usually do the job.
  5. The TV control box has two scan reverse toggle switches (which allow the orientation of the TV display to be changed to match finding charts for example.) Initially, however, they can be used to test the status of the system. When the monitors are powered up, and adjusted in brightness to give a visible background, switching the toggle switches will, if the system is OK, result in the bright edge of the TV cathode traversing the screen. If this is not seen then check the monitor brightness settings. If there is still no response then call for help.
  6. Depress the ACQN/COMP button on the A & G controller to move the flat mirror into the beam. With the CCD Camera type 'TV' and with People's Photometer select the particular aperture position.

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Tue Aug 5 05:37:08 MET DST 1997