Display Mode - Tektronix 1S1 Instruction Manual

Calibration – Type 1S1
Fig. 5-41. Typical indicator oscilloscope displays obtained
during check of offset output.
i. With the Type 1S1 VERT POSITION control, position
the bottom of the waveform at the horizontal centerline of
the indicator oscilloscope crt screen (see Fig. 5-41A).
j. With the Type 1S1 DC OFFSET control, position the
top of the displayed waveform on the horizontal centerline
of the indicator oscilloscope crt screen (see Fig. 5-41B),
k. Set the test oscilloscope Vc Range switch to +11.
l. Check that the trace on the test oscilloscope screen
is within 2.4cm of the horizontal centerline. This indi-
cates a voltage excursion of 6 volts ±2% at the Type 1S1
OFFSET OUTPUT jack, or 10 times the display voltage
change produced by the DC OFFSET control.
m. Remove the patch cord from the OFFSET OUTPUT jack
and the test oscilloscope vertical input.
n. Disconnect the coax cables and attenuator from the
50 amplitude calibrator and from the Type 1S1 SIGNAL
IN and EXT TRIG connectors.
26. Check Output DC Level
a. Install the 1X test probe on the test oscilloscope verti-
cal input.
5-36
b. Reset the following test oscilloscope controls:
Vc Range
Input Atten
Comparison Voltage
Millivolts/Cm
Input Coupling
c. Reset the following Type 1S1 controls:
TIME/CM
TRIGGER SENSITIVITY Clockwise

DISPLAY MODE

d. Adjust the indicator oscilloscope Intensity control for a dim
spot.
e. Free run the test oscilloscope trace and set it for a zero-
volt dc reference level.
f. Set the test oscilloscope Input Coupling switch to Dc.
g. Touch the test probe tip to the Type 1S1 OFFSET
OUTPUT jack.
h. Adjust the Type 1S1 DC OFFSET control to position the
test oscilloscope trace to its horizontal centerline.
I. Touch the test probe to the junction of D183 and D185
(see Fig. 5-42).
Fig. 5-42. Left side of Type 1S1 showing test points for
checking dc vertical output voltage.
j. Set the Vc Range switch to +1.1.
k. Check that the test oscilloscope trace is now within
0
100
6.700
10
Gnd
50 nSEC
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