Repair Vco - Tait TM9100 Service Manual

If either or both the maximum and minimum frequencies are incorrect, the
Task 30 —

Repair VCO

VCO circuitry is faulty.
1.
2.
3.
4.
5.
6.
7.
TM9100 Service Manual
© Tait Electronics Limited August 2005
Remove the can.
VCO BOT
Check the VCO. The circuitry is based on Q5000
(see Figure 9.13).
If a fault is found, repair it and go to
to Step 7.
Repeat Step 1 and Step 2
frequency.
Repeat Step 4 and Step 5
frequency.
If the frequencies are now correct, resolder R542 in position
(see Figure 9.12), and go to
still not correct, go to Step
Resolder R542 in position (see
board assembly and go to
Step 4. If no fault is found, go
of Task 28 to measure the maximum VCO
of Task 28 to measure the minimum VCO
"Final Tasks" on page
7.
Figure 9.12). Replace the main-
"Final Tasks" on page 147.
Frequency Synthesizer Fault Finding
147. If they are
211