316
Transmitter Fault Finding (40W/50W)
TM8100/TM8200 Service Manual
© Tait Electronics Limited
June 2006
Task 33 —
Check PIN Switch
In checking the final RF signal path, if no fault is found in the directional
coupler, then check the PIN switch next. The PIN switch may also require
investigation following certain checks in
.
1.
Remove the
LPF
TOP
can.
2.
Remove the three blocking capacitors
C361
,
C362
and
C363
(see
).
3.
Solder one terminal of a 56 pF (VHF) or 18 pF (UHF) test capacitor
to the PCB at the point shown in
. Mount the capacitor
vertically. Use a test capacitor of the type GRM111, DLI C17,
Murata 1210, or the equivalent.
4.
Solder a 50
Ω
test lead to the PCB. Solder the outer sheath to the test
pad shown in
, and solder the central wire to the other
terminal of the test capacitor.
5.
Connect the test lead to the test set.
6.
Enter the CCTM command
326 5
to set the transmitter power level
to the maximum.
7.
Enter the CCTM command
101
x x
0
, where
x
is the lowest
frequency (in hertz) for maximum power, as given in
(B1),
(H5) or
(H7).
8.
Enter the CCTM command
33
to place the radio in transmit mode.
9.
Measure the RF output power. This should be:
10.
Enter the CCTM command
32
to place the radio in receive mode.
11.
Enter the CCTM command
101
x x
0
, where
x
is the highest
frequency (in hertz) for maximum power, as given in
(B1),
(H5) or
12.
Repeat
to
13.
If the power in both the above cases exceeds 70W (VHF) or 60W
(UHF), go to
. If it does not, the circuitry of the PIN switch
is suspect; go to
14.
Remove the test lead and test capacitor, resolder the blocking
capacitors in position, and go to
.
RF output power: more than 70W (VHF)
more than 60W (UHF)
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...
