Tait TB8100 Service Manual page 10

Power Amplifier Circuit Description
Figure 7.1 PA high level block diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
Figure 7.2 PA control, RF and power supply circuitry block diagram. . . . . . . . . . . . . . . 117
Figure 7.3 Identifying the circuitry on the 28V PA boards . . . . . . . . . . . . . . . . . . . . . . . 123
Figure 7.4 Identifying the circuitry on the 12V PA boards . . . . . . . . . . . . . . . . . . . . . . . 125
Power Amplifier Fault Finding
Figure 8.1 Identifying the circuit boards in a 28V PA . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Figure 8.2 Identifying the circuit boards in a 12V PA . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Figure 8.3 Recommended test equipment set-up for initial checks - 28V PA . . . . . . . . . 134
Figure 8.4 Recommended test equipment set-up for initial checks - 12V PA . . . . . . . . . 135
Figure 8.5 Connections on the fan contact board. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
Figure 8.6 Visual inspection points for a 28V PA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Figure 8.7 Additional visual inspection points for a 12V PA. . . . . . . . . . . . . . . . . . . . . . 147
Figure 8.8 Recommended test equipment set-up for circuit board checks - 28V PA . . . . 149
Figure 8.9 Recommended test equipment set-up for circuit board checks - 12V PA . . . . 150
Figure 8.10 Location of test points on the control board . . . . . . . . . . . . . . . . . . . . . . . . . 153
Figure 8.11 Location of test points on the 6W board. . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
Figure 8.12 Location of test points on the splitter and combiner boards . . . . . . . . . . . . . . 160
Figure 8.13 Location of test points on the 60W board . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
Figure 8.14 Location of the test points and input coupling components on the
LPF/directional coupler board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166
Figure 8.15 Test equipment set-up for the boost regulator board . . . . . . . . . . . . . . . . . . . 169
Figure 8.16 Location of test points on the boost regulator board . . . . . . . . . . . . . . . . . . . 169
Power Amplifier Disassembly and Reassembly
Figure 9.1 Removing the airflow duct and cover. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175
Figure 9.2 Removing the front panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176
Power Amplifier Board Replacement
Figure 10.1 Circuit board connecting links . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
Figure 10.2 Replacing the 6W board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
Figure 10.3 Replacing the 60W board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
Figure 10.4 Replacing the 60W RF power transistor . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
Figure 10.5 Replacing the control board. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
Figure 10.6 Replacing the LPF/directional coupler board . . . . . . . . . . . . . . . . . . . . . . . . 189
Figure 10.7 Replacing the splitter/combiner boards . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191
Figure 10.8 Replacing the boost regulator board in a 12V PA . . . . . . . . . . . . . . . . . . . . . 194
Power Amplifier Spare Parts
Figure 11.1 PA mechanical assembly - 28V PAs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
Figure 11.2 PA mechanical assembly - 12V PAs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198
Figure 11.3 PA mechanical assembly - covers and airflow duct. . . . . . . . . . . . . . . . . . . . . 199
Power Management Unit Circuit Description
Figure 12.1 PMU high level block diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202
Figure 12.2 PMU microprocessor functional block diagram . . . . . . . . . . . . . . . . . . . . . . . 204
Figure 12.3 PMU AC module block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206
Figure 12.4 PMU DC module block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208
Figure 12.5 Identifying the circuitry in the AC module . . . . . . . . . . . . . . . . . . . . . . . . . . 211
10 TB8100 Service Manual
© Tait Electronics Limited September 2006