
194
Frequency Synthesizer Fault Finding
TP9100 Service Manual
© Tait Electronics Limited
May 2005
Task 26 —
Check Switching
to Transmit Mode
If no transmit frequency is detected in the check of the transmit VCO, first
check that the transmit-receive switch is functioning correctly.
1.
Resolder
R542
in position (see
2.
Enter the CCTM command
335 1
to switch on the supply to the
transmit VCO.
3.
Measure the voltage at the second collector (pin 3) of
Q506
(see
). The voltage should be:
4.
Enter the CCTM command
335 0
to switch off the supply.
5.
Again measure the voltage at the second collector of
Q506
.
6.
If the voltages measured in
are correct, go to
. If they are not, the switching network is suspect; go to
.
pin 3 of Q506: 4.3
±
0.1V DC (after entry of CCTM 335 1)
pin 3 of Q506: 0V DC (after entry of CCTM 335 0)
Summary of Contents for TP9100
Page 1: ...TP9100 portables Service Manual MPA 00005 01 Issue 1 00 May 2005 ...
Page 4: ...4 TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 10: ...10 TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 74: ...74 Circuit Descriptions TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 78: ...78 TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 100: ...100 General Information TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 126: ...126 Disassembly and Reassembly TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 148: ...148 Interface Fault Finding TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 158: ...158 Power Supply Fault Finding TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 250: ...250 Transmitter Fault Finding TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 268: ...268 Receiver Fault Finding TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 294: ...294 Spare Parts TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 298: ...298 Antenna Identification Chart TP9100 Service Manual Tait Electronics Limited May 2005 ...