Tektronix 1S1 Instruction Manual page 118

Amplitude Calibrator
Display
Millivolts/Cm
Input Atten
Millivolts/Cm Variable
Vc Range
Comparison Voltage
Input Coupling (Chan-
nel A)
Input Coupling (Channel
B)
41. Check Ext Horiz Atten -Manual Scan
a. Test equipment setup is shown in Fig. 5-59.
b. Disconnect the probe from the test oscilloscope vertical
input.
c. Connect a BNC/banana patch cord from the Type 1S1
EXT HORIZ INPUT jack to the test oscilloscope vertical
input.
d. Connect a banana/banana patch cord from-the OFF-
SET OUTPUT jack to the jack at the Type 1S1 EXT HORIZ
INPUT, as shown in Fig. 5-59. The patch cord from the Type
1S1 HORIZ OUTPUT jack to the indicator oscilloscope Ext
Horiz Input jack should remain in place.
e. Set the test oscilloscope trace for a zero-volt dc ref-
erence level.
f. Reset the following test oscilloscope controls:
Vc Range
Input Coupling
g. Adjust the Type 1S1 DC OFFSET control to center the
trace on the test oscilloscope crt screen.
h. Adjust the Type 1S1 VERT POSITION control and the
indicator oscilloscope Horizontal Position control to position
the displayed spot on the indicator oscilloscope crt screen
at the intersection of the horizontal centerline and the 1-cm
vertical graticule line (see Fig. 5-60A).
i. Set the test oscilloscope Vc Range switch to +11.
j. Turn the DC OFFSET control counterclockwise to re-
turn the test oscilloscope trace to its horizontal centerline.
k. Turn the Type 1S1 VERT POSITION control counter-
clockwise to position the displayed dot at the horizontal
centerline of the indicator oscilloscope crt screen.
l. Check that the dot is now within 0.32 cm of the 9-cm
graticule line (see Fig. 5-60A), representing a minimum
deflection factor of 1 volt/cm ±4% with the EXT HORIZ
ATTEN control fully clockwise.
m. Remove the banana/banana patch cord connected
from the OFFSET OUTPUT jack to the EXT HORIZ INPUT
jack. (Leave the patch cord that is connected to the
oscilloscope.)
Off
A-Vc
50
R =
Calib (at detent)
0
4.000
Gnd
Gnd
-11
Dc
Fig. 5-60. Typical indicator oscilloscope displays for checking
EXT HORIZ ATTEN control range.
n. Disconnect the BNC patch cord connector from the
test oscilloscope vertical input and connect it to the indi-
cator oscilloscope Cal Out connector.
o. With the indicator oscilloscope Horizontal Position con-
trol, position the displayed dot at the left edge of the indi-
cator oscilloscope graticule.
p. Slowly turn the Type 1S1 EXT HORIZ ATTEN control
fully counterclockwise.
q. Check that the horizontal deflection can be reduced
to 6.25cm or less, representing a maximum deflection factor
of 16 volts/cm or more (see Fig. 5-60B).
Calibration – Type 1S1
5-55