Tektronix 1S1 Instruction Manual page 80

Fig. 5-18. Fast ramp and comparator adjustments on right side of Type 1S1 (unit is positioned upside-down on test bench).
d. Set the indicator oscilloscope Intensity control for a
dim trace.
e. Reset the following Type 1S1 controls:
TIME/CM
DISPLAY MODE
TIME POSITION
FINE
Fig. 5-19. Typical test oscilloscope display for checking adjust-
ment of R320 (COMPARATOR LEVEL).
50µSEC
MAN
Clockwise
Clockwise
f. Adjust the Type 1S1 MANUAL SCAN control to posi-
tion the displayed spot about 0.5cm from the left edge of
the graticule.
g. Connect the test probe to the collector of Q384 (See
Fig. 5-18).
h. Trigger the test oscilloscope display.
i. Check for a waveform similar to that shown in Fig.
5-19. The transition to the spike in the trailing edge of the
waveform should be about 20 mv (I cm) down from the top
of the pulse.
j. Adjust R320 (COMPARATOR LEVEL) if the display is
not as indicated. See Fig. 5-18 for the location of R320.
k. Remove the probe from the test point.
10. Adjust 50 nS Ramp Timing
a. Leave the time-mark generator connected to the Type
1S1 SIGNAL IN connector.
b. Set the generator for a 50-Mc output signal.
c. Reset the following Type 1S1 controls:
TIME/CM
DISPLAY MODE
RECOVERY TIME
TIME POSITION
FINE
d. Adjust the variable attenuator to produce approxi-
mately 4cm of vertical deflection on the indicator oscillo-
scope crt screen.
Calibration – Type 1S1
5 nSEC
NORMAL
Counterclockwise (not
SYNC)
Centered
Centered
5-17