The voltage at U2-1 should vary when CLOSED LOOP AD-
JUST Control R12 is varied over its range.
NOTE
If the setting of R12 is changed, refer to the section on setting RF
drive in the Tuning/Frequency Change Procedure in SECTION
V, Maintenance, for proper adjustment of RF drive.
LOCATION
COMPONENT
FUNCTION/DESCRIPTION
D5
R2
When S1 is in the “Open Loop” position, R2 adjusts RF drive level to the power ampli-
fier, by varying supply voltages to driver sections 8A and 8B.
D6
R12
When S1 is in the “Closed Loop” position, R12 adjusts RF drive level to the power am-
plifier by varying supply voltages to driver sections 8A and 8B.
D6
S1
Selects either open loop or closed loop operation.
Table E-1. Driver Supply Regulator Board A22
Controls and Indicators
Section E - Driver Supply Regulator (A22)
888-2297-002
E-5
WARNING: Disconnect primary power prior to servicing.
