User's Manual Part 2

T6T 300 Watt VHF Transmitter Page 109 Maintenance
(5) Re-establish the ac and/or dc supplies.
(6) Switch power on at the radio using the rear mounted Supply switch.
(7) Ensure the front panel Ready indicator is lit and the Alarm indicator is unlit.
(8) Carry out a BIT interruptive test as detailed in the procedure To Initiate a BIT Test on page 102.
(9) Set the rear panel Supply switch to Standby. Isolate the amplifier from the ac and/or dc supplies.
(10) Refit the amplifier top cover. The amplifier can now be returned to service.
Removing and Refitting the Power Supply Modules
The Power Supply modules are located as shown in Fig 34. The removal diagram is shown in Fig 39.
Dangerous voltage is present within the T6T VHF amplifier. Care must be taken by personnel
to avoid accidental contact with exposed circuitry when the covers are removed and power
is applied to the radio.
Removal
Before attempting to remove the Power Supply modules, ensure that the amplifier is isolated from the ac
and dc input supplies. Disconnect the drive assembly cables at CN5 and CN8. Disconnect the antenna
cable to the Combiner. Then proceed as follows:
(1) Remove the amplifier top and bottom covers as described on page 106.
(2) Support the amplifier on its side.
(3) Locate the power supplies. From the bottom half of the unit remove the two M4 x 8 mm
countersunk screws that secure each power supply to the amplifier mainframe. These screws
are accessed through clearance holes in the Combiner BIT module. During this operation
support the power supply from the top half of the unit.
(4) Withdraw each power supply from the chassis sufficient to allow access to the power terminal
blocks taking care not to damage the ac terminal plastic supply guard.
(5) Remove the CN4 connectors (PSU-1 and PSU-2 to the Combiner BIT module, CN10 and CN11
respectively).
(6) Disconnect the dc wires from the power supply terminal block (PSU-1 and PSU-2 to the
Combiner BIT module, CN1 and CN3 respectively).
(7) Slide back the terminal block cover and disconnect the ac wires from the three connector terminal
block (marked L N E).
(8) Carefully remove each power supply from the transmitter.
Refitting
To refit the Power Supply modules:
(1) With the amplifier on its side hold each power supply near to its securing position in the top half
of the radio.
(2) Slide back the terminal block cover and connect the ac wires to the three connector terminal
block (marked L N E); brown to terminal L, blue to terminal N and yellow/green to terminal E.
WARNING Dangerous Voltage