Adjustments; Pll Adjustment - HP 9122D Service Manual

TROL'BLESHOOTI'G
Adjustments
PLL
Adjustment
The Phase LockL.Jop (PLL) adjustment is performed
1S
follows. The PLL adjustment should be performed
when the umt e:utnts read/verify errors or fails the PLL test (TEST
I·n
Use figure 4-1 or -t- 2 for locating test points.
4--14-
1. Power on the unit, and allow the power-on selt-test to finish,
2. After two minutes warm up, attach the frequency counter test leads to tht!
veo
test-point
(TP 1 1). The freque:lcy should be 500K Hz ± 5%. If adjustment is necessary, adjust the variable
resistor R 11 for a frequency of 500 KHz±.l%(+-1 KHz).
3. Verify disc operation.