TB 9-6625-2139-24
(16) Set oscilloscope calibrator LEVEL SINE output for 5 divisions of vertical
display on TI.
(17) Set CH 1 VOLTS/DIV switch to .5.
(18) Adjust R434 (+) AUTO (fig. 2) so display just solidly triggers on positive peak of
signal. (R)
(19) Press A TRIGGER SLOPE pushbutton to IN:
and adjust A TRIGGER
LEVEL control fully ccw.
(20) Adjust R435 (-) AUTO (fig. 2) so display just solidly triggers on the negative
peak of signal. (R)
(21) Connect oscilloscope calibrator CHAN 1 with LEVEL SINE output to one side
of a BNC tee. Connect BNC tee to TI CH 1 using an Xl0 attenuator and a 50 : feedthrough
termination. Connect the other side of BNC tee to TI EXT INPUT.
(22) Set CH 1 VOLTS/DIV switch to 10m and A TRIGGER A SOURCE switch
to EXT.
(23) Set oscilloscope calibrator LEVEL SINE output for 2.2 divisions of vertical
display on TI.
(24) Adjust A TRIGGER LEVEL control for a stable display.
(25) Set HORIZONTAL MODE switch to B and adjust B TRIGGER LEVEL
control for a stable display.
(26) Set CH 1 VOLTS/DIV switch to .1.
(27) Adjust R627 B TRIGGER SENSITIVITY (fig. 1) so that a display can just be
B TRIGGER LEVEL control. (R)
maintained by adjusting the
(28) Repeat paragraph 10 a above.
11. Calibrator Amplitude
a. Performance Check
(1) Position controls as listed in (a) through (l) below:
(a) POSITION controls to midrange.
(b) VERTICAL MODE CH 1 BOTH CH 2 switch to CH 1.
(c) VERTICAL MODE TRIGGER SOURCE CH 1 and CH 2 pushbuttons to
COMPOSITE (AN/USM-488).
(d) CH 1 AC GND DC switch to DC.
(e) HORIZONTAL MODE switch to A.
(f) X10 CAL control to in position.
(g) A TRIGGER P-P AUTO pushbutton pressed.
