TM8100/TM8200 Service Manual
Transmitter Fault Finding (40W/50W)
279
© Tait Electronics Limited
June 2006
Task 11 —
Power and Current
Are Low
If the RF output power and the supply current are uniformly low at all
frequencies, one of the PAs is suspect or the input to the PAs is reduced.
Check each PA in turn:
1.
For the first PA (Q310), enter the CCTM command
331
to check the
DAC value of final bias 1 (
CDC
TX
FIN
BIAS
1
). Record the value
x
returned.
2.
Note the current reading on the DC power supply.
3.
Enter the CCTM command
331 1
to turn off final bias 1.
4.
Enter the CCTM command
33
to place the radio in transmit mode.
5.
Note the RF output power measured at the test set. This should be
as shown in
6.
If the RF power is correct, go to
to repeat the check with the
second PA. If it is not, enter the CCTM command
32
to place the
radio in receive mode, and carry out
and then
.
7.
For the second PA (Q309), enter the CCTM command
332
to check
the DAC value of final bias 2 (
CDC
TX
FIN
BIAS
2
). Record the value
y
returned.
8.
Note the current reading on the DC power supply.
9.
Enter the CCTM command
332 1
to turn off final bias 2.
10.
With the radio still in transmit mode, note the RF output power
measured at the test set. This should be as shown in
11.
Enter the CCTM command
32
to place the radio in receive mode.
12.
If the RF power measured in
is correct, go to
and then
.
Table 11.5
RF output power of individual RF power amplifiers at different frequencies
Frequency band
Frequency within band
Lowest frequency
Centre frequency
Highest frequency
B1
38 ± 5W
48 ± 5W
33 ± 5W
H5
16 ± 5W
17 ± 5W
21 ± 5W
H7
25 ± 5W
32 ± 5W
40 ± 5W
Summary of Contents for TM8235
Page 1: ...TM8100 mobiles TM8200 mobiles Service Manual MMA 00005 04 Issue 4 June 2006...
Page 10: ...10 TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 62: ...62 Description TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 148: ...148 Disassembly and Reassembly TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 162: ...162 Servicing Procedures TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 178: ...178 Interface Fault Finding TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 258: ...258 Receiver Fault Finding TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 446: ...446 Spare Parts TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
