Tektronix 1S1 Instruction Manual page 116

Fig. 5-58. Typical indicator oscilloscope real-time displays
showing interdot and retrace blanking.
g. Check that the displayed dot remains nearly stationary
on the crt screen.
h. Switch the SAMPLES/CM control out of SWEEP OFF
position and set to fully clockwise.
40. Check Blanking
a. Reset the following indicator oscilloscope controls:
Horizontal Display
Stability
Time/Cm
b. With the Type 1S1 DC OFFSET control, position the
free-running trace at the horizontal centerline of the indicator
oscilloscope screen.
c. Position the start of the sweep at the left edge of the
graticule with the indicator oscilloscope Horizontal Position
control.
d. Trigger the display with the indicator oscilloscope
triggering controls.
e. Check the display for blanked areas of from 1 µsec to
5 µsec (0.5 cm to 2.5 cm) between bright portions of the
waveform (see Fig. 5-58A) . This is interdot blanking.
f. Set the indicator oscilloscope Time/Cm switch to .5
mSec.
g. Check the display for a blanked area during the re-
trace portion of the Type 1S1 staircase generator cycle,
similar to that shown in Fig. 5-58B.
h. Turn the Type 1S1 DC OFFSET and VERT POSITION
controls fully clockwise.
i. Check that the crt beam is deflected completely out
of the viewing area during retrace.
j. Set the indicator oscilloscope Horizontal Display switch
to the position used previously (either Ext X1 or Ext X10).
The Ext Horiz Input Variable control should still be set for
a deflection factor of 1 volt/cm.
k. Set the indicator oscilloscope triggering controls to
hold off the sweep generator.
l. Position the trace on the screen with Type 1S1 DC
OFFSET control and the indicator oscilloscope Horizontal
Position control.
NOTES
Calibration – Type 1S1
A
Clockwise (Free Run)
2 µSec
5-53