Powering up the TV system

To operate the system follow these steps:

1. Make sure all lights, including torches, are out in the dome.
2. Turn on the power of the Finder (and if necessary, Cass) monitors in Rack 1 and let them warm up so that you can see if there is any image on the TV cameras.
3. Ensure that the gain controls for Cass and Finder are turned fully OFF (turned anti-clockwise until they click).
4. Press the black ON button on both control boxes. The lights marked DELAY and RESET will come on. Wait about 15 seconds until they go out and the green ON light comes on in each case. If RESET does not go out, press OFF, check step (3) and try again.
5. Each 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 check 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. To use the TV system, you will need to have:-
   1. TV probe centred.
   2. Flip Mirror viewing field or slit as desired.
   3. Comparison Mirror out of the way.
   4. Autoguider Probe out of the way.
7. To remove flickering of picture and white screen at start-up press FINDERSEL'D and then the DIRECT button.
8. The bias has been selected to give a black picture when the camera is started up otherwise the light level on the monitor would be very high in a bright sky. Decrease the BACKGROUND control (Section ) until you begin to see white noise on the screen.