Tait TB8100 Service Manual

156 Power Amplifier Fault Finding TB8100 Service Manual
© Tait Electronics Limited September 2006
Task 1 —
Check Voltage
Levels
1. Set up the test equipment as shown in Figure 8.8 on page 149 (28V
PA) or Figure 8.9 on page 150 (12V PA).
2. Run the Service Kit and connect to the base station.
3. Once connected to the base station, ensure it is in Run Mode.
4. Measure the voltage at pins 2 and 3 of SK101:
■ For a 12V PA, if the voltage is 28V ±1V, go to Step 9. If it is not,
go to Step 5.
■ For a 28V PA, if the voltage is 28V ±2V, go to Step 9. If it is not,
go to Step 6.
5. Measure the voltage at P200 (where the DC supply wire is soldered
to the board). The voltage should be 28V. If it is, replace the 6W
board. If it is not, go to “Boost Regulator Board (12V PA Only)”
on page 168.
6. Measure the voltage at the pin of the DC input feedthrough filter.
The voltage should be 28V. If it is, go to Step 7. If it is not, check
the connection from the power supply to the PA.
7. Check the connection between the pin of the feedthrough filter and
the board. If the connection is not faulty, go to Step 8. If it is faulty,
repair and then go to Step 8.
8. Measure the voltage at pins 2 and 3 of SK101 again. The voltage
should be 28 V. If it is, go to Step 9. If it is not, replace the 6W board.
9. Measure the voltage at TP206 (PIN-BIAS). The voltage should be
between 2V and 2.5V. If it is, go to Task 2
. If it is not, replace the
6W board.
Task 2 —
Check Driver
Temperature Sensor
1. Select Diagnose > Power Amplifier > Control Tests and check that
the driver temperature reading is correct (e.g. if the PA is at ambient
room temperature and not transmitting, the reading on the gauge
should be approximately the same as the ambient temperature). If it
is, go to Task 3
. If it is not, go to Step 2.
2. Remove the links from SK102. Using an oscilloscope, check that
data is present on pin 4 of the control board connector. If it is, replace
the 6W board. If it is not, replace the control board and go to Task 3
.
28V
12V
12V
28V

Tait TB8100 Specifications

General

Brand	Tait
Model	TB8100
Category	Accessories
Language	English