Vcxo And Tcxo Outputs - Tait TM9100 Service Manual

9.9

VCXO and TCXO Outputs

If the 3V power supply is not faulty, check the VCXO output as follows:
Task 35 —
VCXO Output
1.
2.
3.
4.
5.
218 Frequency Synthesizer Fault Finding
Use an oscilloscope probe to check the VCXO output at C536 —
probe the via next to C536 (see
VCXO output at C536: sine wave of 1.1 ± 0.2 V
If the signal is correct, go to
The VCXO circuitry under the
can.
VCXO BOT
Locate and repair the fault in the VCXO (Q501, Q503, XL501 and
associated components) (see
Confirm the removal of the fault and go to
failed, replace the main-board assembly and go to
page 147.
Figure 9.16). The signal should be:
on 1.4 ± 0.2 V DC
pp
Task 36. If it is not, go to
can is faulty. Remove the
VCXO BOT
Figure 9.17).
Task 36. If the repair
"Final Tasks" on
TM9100 Service Manual
© Tait Electronics Limited August 2005
Step 3.