Performance C heck/C alibration—Type 3 2 4
TABLE 5-5
Magnified Sweep Timing Accuracy
T IM E /D IV
switch
setting
Time-mark
generator
output
CRT display
(markers/
division)
Allowable error
for given
accuracy
1 ys
0.1 ys
2
0.4 division
(within 5%)
2 ys
0.1 ys
4
5 ]is
1 ys
1
0.32 division
(within 4%)
10 ys
1 ys
2
20 ys
1 ys
4
50 lis
10 y$
1
1 ms
10 ys
2
.2 ms
10 ys
4
.5 ms
0.1 ms
1
1 ms
0.1 ms
2
2 ms
0.1 ms
4
5 ms
1 ms
1
10 ms
1 ms
2
20 ms
1 ms
4
50 ms
10 ms
1
.1 s
10 ms
2
.2 s
10 ms
4
0.4 division
(within 4%)
b.
Set the horizontal POSITION control to the center
of its range. Reduce the IN T E N S IT Y control setting to
the minimum level that allows the dot to be viewed.
c.
CHECK—CRT display for dot within 0.5 division
of the center vertical line.
NOTE
This tolerance is provided as a guide to correct
instrument operation and is not an instrument
specification.
d.
ADJUST—Ext Horiz Pos adjustment, R412 (see
Fig. 5-12B), to position the dot to the center of the
graticule.
37. Check/Adjust External Horizontal 10X
O
Compensation
a.
Set the EXT T R IG OR H O R IZ A T T E N switch
(side panel) to 10X.
b.
Connect the standard amplitude calibrator to the
EXT TR IG OR H O R IZ INPUT connector with the 42-
inch BNC cable.
c. Set the standard amplitude calibrator for a five-
volt square-wave output.
d. Connect the 10X probe to the input connector of
the test oscilloscope.
e. Set the test oscilloscope for a vertical deflection
factor of 0.05 volt/division (0.5 volt/division at 10X
probe tip) at a sweep rate of 0.5 millisecond/division.
Adjust the triggering controls when necessary to provide
a stable display.
f. Connect the 10X probe tip to the trigger compen
sation test point (point T , Horizontal board; see Fig.
5-12B). Be sure the probe is compensated.
g.
CHECK—Test oscilloscope display for optimum
square-wave response (optimum square corner and flat
top).
h. A D JU S T—C206 (see Fig. 5-12B) for optimum
square-wave response (use low-capacitance screwdriver).
i. Disconnect the test oscilloscope.
38. Check External Horizontal Operation
a.
CHECK—CRT display for horizontal deflection of 6.7
to 10 divisions between dots (0.2 to 0.3 volt/division).
b.
Set the standard amplitude calibrator for a 0.5-volt
square-wave output.
c.
Set the E X T T R IG OR H O R IZ A T T E N switch to
1X.
d. CHECK—CRT display for horizontal deflection of
6.7 to 10 divisions between dots (20 to 30 millivolts/
division).
e.
R o ta te th e E X T H O R IZ V A R control fully
cou nterc I ock w ise.
f.
CHECK—CRT display not more than one-tenth of the
deflection measured in previous step (indicates 10:1 range
or greater).
®
5-25