Replacing The Low Pass Filter/Directional Coupler Board - Tait TB8100 Service Manual

10.6 Replacing the Low Pass Filter/Directional Coupler
Board
Removal
12V
Refitting
188 Power Amplifier Board Replacement
Important
If you replace the LPF/directional coupler board, you must
recalibrate the detector bias voltages and PA output power
using the Calibration Kit. Refer to the Calibration Kit
documentation for more details.
Important
When replacing the LPF/directional coupler board, check
that the RF input coupling components are placed in the
correct location(s) on the replacement board. These com-
ponents must be correctly placed, or the PA may be dam-
aged when it is keyed.
location of these components, and
lists when they are fitted.
Refer to "Power Amplifier Disassembly and Reassembly" on page 173
details on removing and refitting the cover, and for screw torque settings.
The circled numbers in the following instructions refer to
page 189.
1. Remove the cover.
2. On a 12V PA, remove the boost regulator board (as described in
"Replacing the Boost Regulator Board in a 12V PA" on page
3. Desolder the two tabs and remove the shield lid.
4. Remove the bridging links
board.
5. Desolder the RF links
boards.
6. Remove the M3 Torx screws securing the N-type connector to the
heatsink.
7. Desolder and remove the N-type connector, leaving the ground plate
d
soldered in place on the shield wall.
8. Remove the M3 Torx screws securing the board to the heatsink.
9. Carefully lift the board directly upwards off the locating pins
remove it from the heatsink.
1. Refit the board onto the heatsink, ensuring it is correctly positioned
on the locating pins.
2. Secure the board to the heatsink with the M3 Torx screws and tighten
to the correct torque.
Figure 8.14 on page 166
b
connecting the board to the control
c
connecting the board to any adjacent
© Tait Electronics Limited September 2006
shows the
Table 8.4 on page 167
for
Figure 10.6 on
193).
e
and
TB8100 Service Manual