User's Manual

EX7100 Technical Manual - Module Descriptions
©1999 Exicom Technologies (1996) Ltd 7-27 Issue 3 - May 2001
7.5.3 Alignment
There are no user adjustments available on the RF Power Amplifier module. Specialist
factory test equipment and procedures are required to correctly set up the amplifier.
Module Re-tuning
The RF Power Amplifier module is a broad band device and does not require adjustment.
7.5.4 VHF RF Power Amplifier Replacement Procedure
This procedure covers the replacement of the RF Power Amplifier Module
1
.
1. Isolate the EX7100 Terminal from the incoming DC Supply by removing the DC input
wires from the rear panel terminal block.
2. Remove the seven screws securing the bottom cover of the terminal to the finned
heat sink casting as per Figure 7.15.
3. Remove the seven cap screws holding the heat sink casting to the main casting as
per Figure 7.16.
4. Carefully ease the heat sink away from the terminal making sure not to damage the
connecting cables. Note the connector positions and the way that the cables are run
(it is important that all cables are replaced as they were initially run before the module
replacement procedure)
5. Remove the Duplexer cable PL102 from the PA PCB, also remove the mating
end of
the following connections: PL100 (to PL108 transmitter PCB), PL103 (to PL105
transmitter PCB) and PL104 (to PL103 transmitter PCB).
6. Carefully reconnect the above cables to the new Power Amplifier and position the
new module inside the EX7100 terminal casting.
7. Refit the seven cap screws holding the heat sink casting into the main casting. (Refer
to Figure 7.16)
8. Inspect the EX7100 terminal to ensure that it is free of foreign material. Remove and
clean as required.
9. Replace the seven screws securing the bottom cover of the terminal to the finned
heat sink casting. (Refer to Figure 7.15).
10. Connect the antenna to the terminal. Apply power to the EX7100 rear panel and
switch the terminal on.
11. Return to normal operating mode and check that the link is correctly established. If
not refer to Testing & Fault Diagnosis (Section 7.5.2).
12. Re-install the EX7100 back into its rack and re-connect all necessary power,
signalling and antenna cabling.
1
If the VHF Terminal contains the Fan Box Type 8057, please refer to the supplement at the start of this Manual for
removal details prior to replacing the RF Power Amplifier.