TB 9-4931-504-50
(3) Press SWP pushbutton and set DELAYED SWEEP SEC/DIV and DELAYING
SWEEP switches to 2 S. If dot displayed on leading edge is not within one-half division
of top display, perform b(l) through (7) below.
(4) Press CH2 pushbutton. If dot displayed on leading edge is not within one-half
division of top display, perform b(8) through (12) below.
b. Adjustments
(1) Remove connection from CH1 and set both DELAYED SWEEP SEC/DIV and
DELAYING SWEEP switches to 1 S and press HF SYNC pushbutton.
(2) Adjust R233 (fig. 2) for no vertical movement while simultaneously adjusting
R232 (fig. 2) back and forth between fully ccw and 90-degree position. Readjust R232
fully ccw.
(3) Set CH1 VOLTS/DIV switch to 10 mV. Center trace on horizontal graticule
with DC OFFSET control.
(4) Press LO NOISE pushbutton and adjust R242 (fig. 2) for no trace shift while
pressing and releasing NO NOISE button.
(5) Release LO NOISE and HF SYNC pushbuttons. Set CH1 VOLTS/DIV switch
to 50 mV and DELAYED SWEEP SEC/DIV and DELAYING SWEEP switches to 2 S.
(6) Reconnect pulse generator to CH1 and release HF SYNC pushbutton.
(7) Adjust R232 until first dot is on rise of pulse and level with top lead corner of
display.
(8) Repeat (1) above for channel 2.
(9) Adjust R330 (fig. 2) for no vertical shift while simultaneously adjusting R331
ccw.
(10) Repeat technique of (3) and (4) above for CH2, except adjust R344 (fig. 2).
(11) Repeat technique of (5) and (6) above for CH2.
(12) Adjust R331 until first dot is on rise of pulse and level with top lead corner of
display.
22. Low Frequency Comparator
a. Performance Check
(1) Set VOLTS/DIV switch to 10 mV and DELAYED SWEEP SEC/DIV and
DELAYING SWEEP switches to 1 S.
(2) Connect square-wave generator (A6) FAST RISE + OUTPUT to CH1 and CH2
INPUTS, using cable and adapter supplied with square-wave generator and adapter
(B1).
(3) Adjust square-wave generator frequency for 100 kHz and amplitude for 4
divisions of display. If oscilloscope (A3) does not display square wave with flat top and
level within 0.2 division, perform b below.
