Repair Pin Switch - Tait TM9100 Service Manual

If the RF power at the PIN switch is low, the switch is not drawing the
Task 34 —

Repair PIN switch

expected current or the diode is faulty. Check the circuit as follows:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
310 Transmitter Fault Finding (50W/40W Radios)
Remove the can.
PIN TOP
Perform a diode check of D307 (B1 band) or D3507 (H5, H7 bands)
(see Figure 11.27). If it is not faulty, go to
D307 or D3507, and go to
Check the +9 0_
supply to the PIN switch via the following
V TX
resistors on the bottom-side of the PCB (see
Figure 11.29):
B1 band: R389 and R390
H5, H7 bands: R3000, R389 and R390
If any resistor is faulty, replace the resistor as well as D307 (B1) or
D3507 (H5, H7). (A faulty resistor is likely to have resulted in damage
to D307 or D3507.)
With the test lead still connected 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), Table 11.9 (H5) or
Enter the CCTM command 33 to place the radio in transmit mode.
Again measure the RF output power. This should be:
RF output power: more than 70W (B1 band)
more than 60W (H5, H7 bands)
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), Table 11.9 (H5) or
Repeat Step 5 to Step 7.
Remove the test lead and test capacitor, and resolder the blocking
capacitors C361, C362 and C363 (see
If the power in both the above cases is now correct, the fault has been
rectified; go to "Final Tasks" on page
failed; replace the main-board assembly and go to
page 147.
Step 3. If it is, replace
Step 4.
Figure 11.28
Table 11.10 (H7).
Table 11.10 (H7).
Figure 11.27) in position.
147. If it is not, the repair
"Final Tasks" on
TM9100 Service Manual
© Tait Electronics Limited August 2005
and
Table 11.8
Table 11.8