Adjustments
Model 3585A
5-8
A 8 1 R2 Fine
Frequency
Adjustment
A8 1 R 9
O v e n Output
Adjustment
Course
Frequency
Adjustment
A 4 7
A 1 8
A 1 7
Figure 5·3. Oven Oscillator Adjustment Locations
c. Connect the Frequency counter to A2U! .
d . Remove the screw on the A8l Oven assembly that covers the course frequency adjust
ment.
e. Adjust A8I R2 to the center of its range.
f. Adjust the Course Frequency control on the AB l board so that the frequency counter
reads 90MHz ± 1 Hz. Allow time for the oven oscillator to stabilize after each adjustment.
g. Disconnect the frequency counter from A2U! . Reconnect the proper cable to A2U! .
h. Set the synthesizer for:
FREQUENCY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9MHz
AMPLITUDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OdBm
i. Set the 3585A controls for:
INSTRUMENT PRESET
CENTER FREQUENCY . . . . . . . . . . . . . . . . . . . . . 9MHz
COUNTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . on
MANUAL SWEEP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . on
j . Using a BNC "Tee" , connect the synthesizer output to the 3585A 500 input and the ex
ternal Frequency Counter input.
k. Adjust the fine frequency adjustment, A8I R2, (and the course frequency adjustment if
necessary) so that the 3585A counter frequency matches the external Frequency Counter
reading. Again, allow 5-10 minutes between adjustments so that the oven oscillator will
stabilize.
1.
Replace the screw that covers the course Frequency Adjustment.
m. If other adjustments are to be made, reconnect the 3585A IOMHz REF OUTPUT to
the synthesizer reference input.