TB 9-4931-538-40
Figure 21. Overshoot fine adjustments.
25. Feedthrough Compensation Adjustment
a. Set the display menu and mainframe settings to meet the following conditions:
(1) Press Display key. Display Mode to Persist is highlighted. DISPLAY TIME
to Persistence = 500 ms. Screen to Single is highlighted. Graticule to Grid is
highlighted. Bandwidth to 12.4 GHz is highlighted.
(2) Press Channels key. Channel 1 display On is highlighted. Channel 2
through 4 display Off is highlighted. VOLTS/DIV to 10.00 mV/div. OFFSET to Offset =
200 mV. PROBE ATTEN to Chl Atten Factor = 1.000.
(3) Press Timebase key. TIME/DIV to Sweep Speed = 20 ms/div. DELAY to
Delay = 16.0000 ns. Delay Ref at Left is highlighted. Freerun/Trg'd Sweep to
Freerun is highlighted. FREERUN RATE to 3 kHz is highlighted.
(4) Press Network key. Reflect/Trans/Cal to Reflect is highlighted. Step &
Chan 1 to On is highlighted.
b. Connect semi-rigid S and U cables from Channel 1 to Channel 2.
c. Preset the eight adjustments RC1 through RC4 and CC1 through CC4 (fig. 12) on
the vertical assembly A2 fully ccw.
d. The signal on the display should resemble figure 22.