Tait TM9100 Service Manual page 364

In checking the final RF signal path, if no fault is found in the directional
Task 31 —
Check PIN Switch
coupler, then check the PIN switch next. The PIN switch may also require
investigation following certain checks in
page
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
364 Transmitter Fault Finding (25W Radios)
324.
Remove the can.
PIN TOP
Remove the three blocking capacitors C361, C362 and C363
(see Figure 12.18).
Solder one terminal of a 22pF test capacitor to the PCB at the point
shown in Figure 12.18. Mount the capacitor vertically. Use a test
capacitor of the type GRM111, DLI C17, Murata 1210, or the
equivalent.
Solder a 50Ω test lead to the PCB. Solder the outer sheath to the test
pad shown in Figure 12.18, and solder the central wire to the other
terminal of the test capacitor.
Connect the test lead to the test set.
Enter the CCTM command 326 5 to set the transmitter power level
to the maximum.
Enter the CCTM command 101 x x 0, where x is the lowest
frequency (in hertz) for maximum power, as given in
(B1 band) or Table 12.9
Enter the CCTM command 33 to place the radio in transmit mode.
Measure the RF output power. This should exceed 35W.
RF output power: more than 35W
Enter the CCTM command 32 to place the radio in receive mode.
Enter the CCTM command 101 x x 0, where x is the highest
frequency (in hertz) for maximum power, as given in
(B1 band) or Table 12.9
Repeat Step 8 to Step 10.
If the power in both the above cases exceeds 35 W, go to
does not, the circuitry of the PIN switch is suspect; go to
Remove the test lead and test capacitor, resolder the blocking
capacitors in position, and go to
"Transmitter RF Power" on
(H5, H6).
(H5, H6).
Task 33.
TM9100 Service Manual
© Tait Electronics Limited August 2005
Table 12.8
Table 12.8
Step 14. If it
Task 32.