HP 8568B, Performance Tests And Adjustments Manual, Page: 192 / 313

8. 21.4 MHz Bandwidth Filter Adjustments
Equipment
Digital Voltmeter (DVM) . . . . . . . . . . . . . . . . . . . . . . . .HP
10 Step Attenuator . . . . . . . . . . . . . . HP Option
1 Step Attenuator . . . . . . . . . . . . . . . HP Option
Crystal Filter Bypass Network (2 required) . . . . Refer to Figure 3-91
Procedure
1. Position instrument upright as shown in Figure 3-40 and remove
top cover.
2. Set LINE switch to ON and press
PRESET
].
+ 10 V Temperature Compensation Supply Check
3. Connect DVM to (+ 10 VF).
4. DVM indication should be between V dc and + 10.0 V dc. If
voltage is within tolerance, proceed to next step. If voltage is not
within tolerance, refer to Adjustment 10, Step Gain and 18.4 MHz
Local Oscillator Adjustments, for adjustment procedure.
LC Adjustments
5. Set step attenuators to 0
6. Disconnect cable 97 (white/violet) from and connect to
1.
7.
Key in
20
MHz, 100
[
FREQUENCY SPAN
)
200 and press LIN pushbutton.
8.
Press
(
REFERENCE LEVEL
)
and adjust front-panel knob to set signal
peak on screen two divisions from the top graticule.
9. Adjust LC CTR and LC CTR for maximum
MARKER level as indicated by CRT annotation. See Figure
for location of adjustments. If unable to adjust LC CTR
adjustments for satisfactory signal amplitude, increase or decrease
value of
and Refer to 3-3 for range of
values.
\
Figure 3-41.
Location of 21.4 MHz LC Filter Adjustments
3-78 Adjustments