Performance Check/Calibration—Type 422 AC-DC
i
Fig. 5-21. (A) Location of trigger compensation test point and
adjustment (Trigger/Sweep Generator board), (B) typical test
oscilloscope display showing correct compensation, (C) location of
C217 (Vertical Switching and Output Amplifier board).
36. Check High-Frequency Triggering Operation
a. Change the following control settings:
CH 1 and 2 VOLTS/DIV .2
TRIGGERING Source CH 1 & 2
TRIGGERING Coupling AC
TIME/DIV .5 jus
b. Connect the high-frequency constant-amplitude sine-
wave generator to the INPUT 1 connector through the 18-
inch 50-ohm BNC cable, 50-ohm BNC termination and the
BNC T connector. Connect the output of the BNC T con
nector to the TRIG IN connector through a 42-inch 50-
ohm BNC cable.
c. Set the constant-amplitude generator for a 0.2-
division display at five megahertz.
d. CHECK—Stable CRT display can be obtained with
the TRIGGERING Coupling switch set to AC, AC LF REJ
and DC and the TRIGGERING Source switch set to CH 1
and CH 1 & 2 (LEVEL control may be adjusted as neces
sary to obtain a stable display).
e. Set the TRIGGERING MODE switch to NORM
(pulled out).
f. CHECK—Stable CRT display can be obtained with the
TRIGGERING Coupling switch set to AC, AC LF REJ and
DC and the TRIGGERING Source switch set to CH 1 and
CH 1 & 2 (LEVEL control may be adjusted as necessary to
obtain a stable display).
g. Set the constant-amplitude generator for a one-
division display at 15 megahertz.
h. Pull the X I0 MAG switch.
i. CHECK—Stable CRT display can be obtained with the
TRIGGERING Coupling switch set to AC, AC LF REJ and
DC and the TRIGGERING Source switch set to CH 1 and
CH 1 & 2 (LEVEL control may be adjusted as necessary to
obtain a stable display).
j. Set the TRIGGERING Mode switch to AUTO
(pushed in).
c. Set the square-wave generator for a one-division dis
play on the test oscilloscope at a frequency of 10 kilohertz
in the high-amplitude mode.
d. CHECK—Test oscilloscope display for optimum
square-corner at the lower corner of the waveform similar
to Fig. 5-21 B.
e. ADJUST—C302 (see Fig. 5r21A) for optimum
square-wave response.
f. Disconnect all test equipment and replace Q364.
k. CHECK—Stable CRT display can be obtained with
the TRIGGERING Coupling switch set to AC, AC LF REJ
and DC and the TRIGGERING Source switch set to CH 1
and CH 1 & 2 (LEVEL control may be adjusted as
necessary to obtain a stable display).
l. Change the following control settings;
Ch 1 VOLTS/DIV .05
TRIGGERING Source EXT
X I0 MAG Pushed in
m. Set the constant-amplitude generator for a 2.5 divi
sion display (0.125 volt) at its reference frequency (50 kilo
hertz).
5-27
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