Check The Receive And Receive-Audio Functions - Tait TM9100 Service Manual

14.
If the radio does not receive, this can be caused by:
Task 10 —
Check the Receive
and Receive-Audio
Functions
If the cause is already known, go directly to the relevant fault-finding
section.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
146 Servicing Procedures
If the main-board assembly was replaced or if the repair failed, re-
assemble the radio as described in
page 123. Conclude with the tasks of
the synthesizer not being in lock
no carrier detected
a faulty speaker or volume control
no modulation
Use CCTM command 101 x y 0 to set the receive frequency to the
bottom of the band.
Use CCTM command 72 to read the lock status.
If the synthesizer is in lock, go to
lock, repair the radio as described in
Finding" on page 169.
Repeat Step 1 to Step 3
the band
Feed a signal without modulation on the receive channel at –47dBm.
Check for maximum RSSI using:
the indicator on the radio display
the green status LED
CCTM command 63 should return the fed signal strength
±1dBm.
Repeat the check in
should show as empty or close to empty.
If the carrier is detected correctly, go to
detected correctly, try to re-calibrate the radio.
If the re-calibration repairs the fault, go to
If it does not, repair the radio as described in
Finding" on page 227.
Check whether the speaker is the source of the fault, as described in
"Speaker Faulty" on page
If the radio receives audio now, the original speaker was faulty.
Reassemble the radio and go to
radio still fails to receive, reconnect the original speaker and go to
Step 11.
Use CCTM command 804 to read the status of the volume
potentiometer.
"Disassembly and Reassembly" on
"Final Tasks" on page
Step 5. If the synthesizer is not in
"Frequency Synthesizer Fault
with the receive frequency set to the top of
Step 5 with –117dBm. The RSSI indicator
Step
"Final Tasks" on page
414.
"Final Tasks" on page
© Tait Electronics Limited August 2005
147.
9. If the carrier is not
147.
"Receiver Fault
147. If the
TM9100 Service Manual