TB 9-6625-2139-24
(m) A TRIGGER A EXT COUPLING switch to DC.
(2) Connect oscilloscope calibrator CHAN 1 to TI CH 1 using a 50 :
feedthrough termination.
(3) Set oscilloscope calibrator LEVEL SINE output at 10 MHz and approximately
17 mVpp for 3.5 divisions (3.0 divisions for type 2235) of vertical display on TI.
(4) Set CH 1 VOLTS/DIV switch to 50m.
(5) Set A TRIGGER pushbutton to first row listed in table 17 and adjust A
TRIGGER LEVEL control to obtain a stable display. If a stable display cannot be
obtained, perform adjustments listed in table 17.
(6) Repeat technique of step (5) above for remaining A TRIGGER pushbutton
combinations listed in table 17. If a stable display cannot be obtained for each combination,
Test instrument
Test instrument
Test instrument
A TRIGGER LEVEL
adjustments
stable display test
MODE
SLOPE
b
YES
NO
b
NORM
IN:
b
P-P AUTO
IN:
b
P-P AUTO
OUT:
(7) Set HORIZONTAL MODE switch to B. Adjust B INTENSITY control for
suitable viewing.
(8) Verify a stable display can be obtained by adjusting B TRIGGER LEVEL
control in a position other than B RUNS AFTER DLY; if not, perform b below.
(9) Press B TRIGGER SLOPE pushbutton to IN and verify a stable display can be
obtained by adjusting B TRIGGER LEVEL control in a position other than B RUNS
AFTER DLY; if not, perform b below.
(10) Position controls as listed in (a) through (e) below:
(a) VERTICAL MODE CH 1 BOTH CH 2 switch to CH 2.
(b) VERTICAL MODE TRIGGER SOURCE CH 1 pushbutton to out position
(AN/USM-488).
(c) HORIZONTAL MODE switch to A.
(d) B TRIGGER SLOPE pushbutton to OUT.
(e) A TRIGGER A&B INT switch to CH 2 (type 2235).
(11) Move connection at CH 1 to CH 2 using a 50 : feedthrough termination.
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