334
Transmitter Fault Finding (25W Radios)
TM9100 Service Manual
© Tait Electronics Limited
August 2005
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
Table 12.5
.
6.
If the RF power is correct, go to
Step 7
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
Task 12
and then
Task 13
.
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
Table 12.5
.
11.
Enter the CCTM command
32
to place the radio in receive mode.
12.
If the RF power measured in
Step 10
is correct, go to
“RF Signal
Path” on page 354
. If it is not, carry out
Task 12
and then
Task 16
.
Table 12.5
RF output power of individual RF power amplifiers at different frequencies
Frequency band
Frequency within band
Lowest frequency
Center frequency
Highest frequency
B1
29 ± 5 W
34 ± 5 W
29 ± 5 W
H5
5 ± 5 W
12 ± 5 W
27 ± 5 W
H6
13 ± 5 W
19 ± 5 W
28 ± 5 W
Summary of Contents for TM9100
Page 1: ...TM9100 mobiles Service Manual MMA 00017 01 Issue 1 August 2005 ...
Page 4: ...4 TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 10: ...10 TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 22: ...22 Introduction TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 62: ...62 Description TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 96: ...96 TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 138: ...138 Disassembly and Reassembly TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 152: ...152 Servicing Procedures TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 168: ...168 Interface Fault Finding TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 244: ...244 Receiver Fault Finding TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 396: ...396 CODEC and Audio Fault Finding TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 420: ...420 Fault Finding of Control Head TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 426: ...426 Spare Parts TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 430: ...430 TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 444: ...444 TMAA04 05 Ignition Sense Kit TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 448: ...448 TMAA10 01 Desktop Microphone TM9100 Service Manual Tait Electronics Limited August 2005 ...