Tektronix 2445, Instruction Manual

Page: 106 / 351

Performance Check— 2445 Service
b. Connect the Function Generator to the CH 1 input via
a 50 Q BNC cable, a 50 S2 termination, and a 10X attenuator.
c. Set the Function Generator output frequency and
level for a 50-kHz, 4-division display.
d. Set the CH 1 VOLTS/DIV switch to 0.1 V.
e. Set the TRIGGER COUPLING switch to NOISE REJ.
f. CHECK— Display will not trigger (freeruns).
g. Pull the B SEC/DIV knob out, rotate it to 5
ns
and
push it back in.
h. Press the A/B TRIG button to select the B TRIGGER.
i. Set the TRIGGER MODE switch to B TRIG AFT DLY.
j. CHECK— Display will not trigger for any setting of the
LEVEL control.
k. Rotate the B SEC/DIV switch back to 10
ms
(knobs
locked).
I. Move the input signal to CH 2, CH 3, and CH 4 in turn,
selecting each channel as the display source. Repeat parts f
through k for each channel.
4. Check Slope Selection and Verify Line Trigger.
a. Set:
A and B SEC/DIV 2 ms (knobs locked)
X I0 MAG Off (button out)
TRIGGER
MODE AUTO
SOURCE
LINE
COUPLING AC
VOLTS/DIV
CH 1 5 V
Input Coupling
CH 1
1 MQ DC
In the next p art
,
DO N O T connect the probe ground
lead to the ac pow er source.
b. Attach the 10X probe to the CH 1 OR X input connec­
tor and connect the probe tip to the ac power source.
c. CHECK— Display can be triggered in both the
+ (plus) and — (minus) positions of the SLOPE switch
using the TRIGGER LEVEL control and that the displayed
slope agrees with the selected slope.
d. CHECK— Display phase shifts slightly as the TRIG­
GER COUPLING switch is changed from AC to DC.
e. CHECK— Display freeruns at either extreme of the
TRIGGER LEVEL control.
f. Disconnect the test setup.
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