Tektronix 1S1 Instruction Manual page 83

Calibration – Type 1S1
11. Adjust Delay Zero
a. Test equipment setup is shown in Fig. 5-22.
b. Connect the tunnel diode pulse generator to the Type 1S1
SIGNAL IN connector and turn on the generator.
c. Pull out on the MAGNIFIER knob and set the TIME/CM
switch to 1 nSEC.
d. Trigger the display with the TRIGGER SENSITIVITY
control. (For this check, the TRIGGER SENSITIVITY control
must be set to the most counterclockwise position that
provides stable triggering).
e. Check that the negative-going pulse rise occurs from 3 to
6 cm after the start of the sweep (see Fig. 5-23). This control
will be out of adjustment if step 7 was performed.
f. Adjust R370 (DELAY ZERO) to position the pulse rise at
the 4-cm graticule line if the display is not as indicated. See
Fig. 5-24 for the location of R370.
g. Turn off and remove the tunnel diode pulse generator.
12. Adjust Sweep Length
a. Turn the TRIGGER SENSITIVITY control fully clockwise.
b. Check that the length of the sweep is between 10.0 cm
and 10.3 cm.
Fig. 5-24. Right side of Type 1S1 showing location of DELAY ZERO and SWEEP LENGTH controls. (Unit is positioned upside-down on
test bench.)
5-20
Fig. 5-23. Typical indicator oscilloscope display for checking
adjustment of R370 (DELAY ZERO).
c. Adjust R290 (SWEEP LENGTH) for approximately 10.2
cm of trace if the length was not between the given limits. See
Fig. 5-24 for the location of R290.
d. Turn off the indicator oscilloscope and disconnect both
ends of the extension cable.
e. Disconnect the patch cord from the Type 1S1 HORIZ
OUTPUT jack.