System Error - Tait TM9100 Service Manual

A system error indicates a fault in the calibration of either the FCL or the
Task 1 —

System Error

frequency synthesizer. To determine which is faulty, calibrate the VCXO
and the transmit VCO as described below. (Always calibrate the former first,
because the latter depends on the former.)
1.
2.
3.
4.
5.
6.
7.
8.
9.
TM9100 Service Manual
© Tait Electronics Limited August 2005
Place the radio in CCTM.
Enter the CCTM command 301 0 10 to calibrate the VCXO.
The response will be one of the following three messages:
"passed sanity check. Cal'd values put into effect"
"failed sanity check. Cal'd values not in effect"
"Cal failed: lock error"
The first two messages will be preceded by four calibration values.
In the case of the first message (passed), go to
the second and third messages (failed), the FCL is suspect; go to
"Power Supply for FCL" on page
Enter the CCTM command 302 0 10 to calibrate the transmit VCO.
The response will be one of the three messages listed in
The first two messages will be preceded by eight calibration values.
Reset the radio and re-enter CCTM.
If the calibration succeeded but the system error persists, replace the
main-board assembly and go to
case of the second message (failed sanity check), go to
case of the third message (calibration failed), go to
radios) or "Power Supplies" on page 173
Enter the CCTM command 205 to reset the calibration values to the
default values. Then enter the CCTM command 302 0 10 again to
calibrate the transmit VCO.
If the calibration succeeded, confirm the removal of the fault, and go
to "Final Tasks" on page
(UHF radios) or "Power Supplies" on page 173
Program the radio with the maximum frequency in the radio's
frequency band: Enter the CCTM command 101 x x 0, where x is the
frequency in hertz.
Enter the CCTM command 72 to determine the lock status in receive
mode. Note the response.
lock status=xyz (x=RF PLL; y=FCL; z=LO2) (0=not in lock; 1=in lock)
Step
215.
"Final Tasks" on page
(VHF radios).
147. If the calibration failed, go to
(VHF radios).
Frequency Synthesizer Fault Finding
4. In the case of
Step 2.
147. In the
Step 6. In the
Step 8 (UHF
Step 8
171