Tektronix 2445A - Page 85

6. Rotate the Δ control to align the delta cursor
with the top of the signal display.
7. CHECK-Vertical Deflection Accuracy (measured
against the graticule)
and þÿ”V Readout Accuracy
are within the limits listed in Table 4-2.
8. Set the TRIGGER LEVEL control at the most
positive voltage that produces a barely triggered,
jittering display for
each position of SLOPE.
9. CHECK-The A Trigger Level readings are
within the limits
given in the + Peak column of
Table
4-2.
10. Set the TRIGGER LEVEL control at the most
negative voltage that produces a barely trig-
gered, jittering display for
each position of
SLOPE.
11. CHECK- The A Trigger Level readings are
within the limits given in the - Peak column of
Table
4-2.
12. Set the TRIGGER LEVEL for a stable display.
13. Pull the SEC/DIV knob out.
14. Set:
B TRIGGER
MODE
SOURCE
COUPLING
SLOPE
NOTE
TRIG AFT
DLY
VERT
DC
+
On CTT instruments, rotate the þÿ” REF OR DL Y
POS control for the specified delay. As the con-
trol is rotated, the readout delay
value will be fol-
lowed
by the word "SET". This value shows the
approximate
delay. A few seconds after control
movement has stopped, the word "SET" will
disappear and the readout delay
value as
measured by the CTT will appear.
This is normal
operation and
not cause for concern.
Performance Check-2445A/2455A Service
15. Adjust Δ REF OR DL Y POS control for a delay
reading of
0.000 ms.
16. Set the TRIGGER LEVEL control to the most
positive voltage that produces
an intensified
point
on the waveform display for each position
of SLOPE.
17. CHECK-The B Trigger Level readings are
within the limits given in the + Peak column of
Table 4-2.
18. Set the TRIGGER LEVEL control to the most
negative voltage that produces
an intensified
point
on the waveform display for each position
of SLOPE.
19. CHECK-The B Trigger Level readings are
within the limits
given in the - Peak column of
Table 4-2.
NOTE
On CTT instruments, repeat sections 16-19
for
TRIG þÿ” DL Y trigger mode using the
+Peak and -Peak columns of Table 4-2.
20. Push the SEC/DIV knob in.
21. Change the VOL TS/DIV to the next position
listed
in Table 4-2.
22. Set the Calibration Generator to the correspond-
ing signal amplitude setting.
23. Press and release the ΔV V pushbutton to obtain
the
þÿ”V readout display.
24. Repeat subparts 4 through 23 of part e for each
VOL TS/DIV setting listed
in Table 4-2.
25. Set the TRIGGER COUPLING to NOISE REJ.
26. Set the CH 1 VOL TS/DIV to 50 mV.
4-7