HP 8568B, Performance Tests And Adjustments Manual, Page: 202 / 313

10. Step Gain and 18.4 MHz Local Oscillator Adjustments
Equipment
Digital Voltmeter (DVM) . . . . . . . . . . . . . . . . . . . . . . . . HP
Power Meter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A
Power Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HP
10 Step Attenuator . . . . . . . . . . . . . . HP Option
1 Step Attenuator . . . . . . . . . . . . . . . HP Option
Procedure
1. Position instrument upright as shown in Figure 3-46 and remove
top cover.
2. The validity of the results of this adjustment procedure is based
in part on the performance of the Log Amplifiers, the Video
Processor, and the Track and Hold. These adjustments must be
done before proceeding with
the
adjustment procedure of the
Step Gain and 18.4 MHz Local Oscillator.
3. Set instrument LINE switch to ON and press
PRESET
).
Connect CAL OUTPUT to RF INPUT.
4.
Key in
[
CENTER FREQUENCY
]
20
MHz,
[
R E F E R E N C E L E V E L
]
- 1 0
0
[
FREQUENCY SPAN
)
0 Hz, 1
100 Hz, and
[
SWEEP TIME
)
20
ms.
IF Gain Adjustment
5. Disconnect cable 97 (white/violet) from and connect cable
to power meter/power sensor. Refer to Figure 3-47 for location of
cable 97 and
6. Adjust front-panel AMPTD CAL adjustment for a power meter
indication of -5
7. Disconnect power meter and reconnect cable 97 to
8. Press LIN pushbutton and MARKER
9. Note MARKER amplitude in and adjust CAL to
70.7 (top CRT graticule line). See Figure 3-47 for location of
adjustment.
3 D T H
1
F I L T E R
S T E P G A I N
C A L
Figure 3-47. Location of IF Gain Adjustment
3-88 Adjustments