Glenayre Document Number: 9110.01002
GL-T8541 PA
09/10/99
REMOVAL AND REINSTALLATION
t8541
p8.
fdk
Copyright © 1997 Glenayre
Page: 8-5
8.7 Combiner Board
8.7.1 Removal
Heed all cautions at the beginning of this section. Refer to Figure 8-6, for details.
1.
Remove the PA cover and the inner PA PCB cover.
2.
Unsolder and remove the three sets of RF input, ground, +28V, and AGC straps that
connect the three power amplifier boards to the combiner board.
3.
Remove the screws that hold the low-pass filter/directional coupler shield to the com-
biner board.
4.
Lift the low-pass filter/directional coupler shield off of the combiner board.
5.
Remove the four screws that secure the RF output connector to the rear wall of the PA
module, and remove the connector bracket from the other side of the connector.
6.
Unsolder the center conductor of the RF output connector from the combiner board and
remove the connector.
7.
Remove the two screws that fasten the combiner board D-sub 25 connector to the rear
wall of the PA module.
8.
Note locations of screws and hardware for later reinstallation. Remove remaining com-
biner board screws and store for later use.
9.
The combiner board can now be lifted off of the PA module heat sink. This procedure
is complete.
8.7.2 Reinstallation
1.
Make certain that there is no grit or other foreign matter in the contact area between
R1 (the three-section, 50-ohm combiner reject load resistor) and heat sink. Apply heat
sink compound lightly to chassis contact area and bottom surface of the resistor.
2.
Place board so that D-sub 25 connector fits correctly into rear of chassis. Fasten con-
nector lightly (finger tight) with hardware.
3.
Reinstall screws removed during step 8 of removal process. Do not tighten yet.
4.
Reinstall the low-pass filter/directional coupler shield to the combiner board. Do not
tighten yet.
5.
Once all screws are installed, tighten all screws, starting with screws holding R1 (the
three-section, 50-ohm combiner reject load resistor). Tighten the D-sub 25 connection
last.
6.
Reinstall the N-type RF output connector to the rear wall of the PA module and
securely tighten the four mounting screws.
7.
Solder the center conductor of the RF output connector to the appropriate pad on the
combiner board.
8.
Slide PA compartment into transmitter chassis to make certain that the D-sub 25 and
the RF Output connectors are correctly aligned for automatic connection to their cor-
responding blend-mate connectors.
9.
Replace the PA cover and the inner PA PCB cover. This procedure is complete.
