TM8100/TM8200 Service Manual
Frequency Synthesizer Fault Finding
209
© Tait Electronics Limited
June 2006
Task 20 —
Check Switching
to Receive Mode
If no receive frequency is detected in the check of the receive VCO, first
check that the transmit-receive switch is functioning correctly.
1.
Resolder
R542
in position (see
2.
Enter the CCTM command
335 0
to switch on the supply to the
receive VCO.
3.
Measure the voltage at the first collector (pin 3) of
Q506
(see
). The voltage should be:
4.
Enter the CCTM command
335 1
to switch off the supply.
5.
Again measure the voltage at the first collector of
Q506
.
6.
are correct, go to
. If they are not, the switching network is suspect; go to
pin 3 of Q506: 5.0
±
0.3 V DC (after entry of CCTM 335 0)
pin 3 of Q506: 0 V DC (after entry of CCTM 335 1)
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...