Service Manual

276

6802800U74-AN

Chapter 7: Radio Frequency Distribution System

Figure 152: Schematic Diagram of MTS 4 Preselector

Preselector

7V DC supply

BR1

BR2

BR3

Antenna LNA

BR4

Exp.

Cabinet

7.3.2.1

Replacing the MTS 4 Preselector

WARNING: RF energy burn hazard. Disconnect power in the cabinet to prevent injury and

equipment damage while disconnecting and connecting antennas.

Process:

1 Remove the Preselector.

See Removing the MTS 4 Preselector on page 276.

2 Reinstall the Preselector.

See Reinstalling the MTS 4 Preselector on page 277.

7.3.2.1.1

Removing the MTS 4 Preselector

Procedure:

1 Remove the door of the cabinet completely.

2 Remove the four screws holding the front panel.

3 Loosen the two screws holding the front section of the top panel and slide off the panel.

4 Loosen the screws fastening the rear section of the top panel and slide off the panel.

5 Unscrew the antenna cable and remove the RX cables connected to the back of the Preselector.

6 Loosen the two fastening screws at the front enough to free the mounting bracket.

7 Slide the Preselector out of the cabinet.

8 Remove the Preselector from the bracket and replace with the new unit.