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Calibration—Type
106
Time-Mark
Generator
—
50-Ohm
BNC
Cable
50-Ohm
Termination
Test
Oscilloscope
In-Line
Termination
5-Nanosecond
GR
Cable
Fig.
6-8.
Initial
test equipment
setup
for steps
7 — 12.
Front-panel
control
settings
REPETITION
RATE
RANGE
1 kHz
MULTIPLIER
10 (clockwise)
SYMMETRY
Midrange
AMPLITUDE
Midrange
HI AMPLITUDE
—
FAST
RISE
H| AMPLITUDE
+ TRANSITION
AMPLI-
TUDE
Midrange
— TRANSITION
AMPLI-
TUDE
Midrange
POWER
ON
7. Adjust Symmetry Range
O
a. Test equipment setup is shown in Fig. 6-8.
b. Connect the OUTPUT (HI AMPLITUDE) connector to the
channel
2 input of the test oscilloscope
through
the five-
nanosecond
GR
cable
and
the
50-ohm
in-line
termination.
6-10
c. Set the test oscilloscope vertical deflection to display
about
four
divisions
and
the sweep
rate
to display
one
complete
cycle
in 10 divisions
(use variable
time/division
control).
d. CHECK
—
Test
oscilloscope
display
for five-division
duration
of the positive portion of the square wave
(50%
duty cycle).
e. ADJUST
—
Symmetry
Range
adjustment,
R9 (see Fig.
6-9A), for five-division duration of the positive portion.
f.
Set the SYMMETRY
control
fully clockwise;
reset the
time/division controls for one complete cycle in 10 divisions.
g.
CHECK—Test
oscilloscope
display
for 5.5 divisions
or
more
duration
of the positive portion of the square wave
(55%
or more;
see Fig. 6-98).
h. Set the SYMMETRY
control fully counterclockwise; reset
the time/division controls for one complete cycle in 10 divi-
sions.
i.
CHECK — Test oscilloscope display for 4.5 division or
less duration
of the
positive
portion
of the square
wave
(45%
or less; see Fig. 6-9B).
j.
Return the SYMMETRY
control to midrange.
@2
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