Tektronix 2A61 Instruction Manual page 41

10. Adjust C424 and C524 (High Frequency O
Common Mode Rejection)
a, Test equipment setup is shown in Fig. 6-13.
b. Connect two patch cords with banana type terminals
to the Audio Generator output terminals.
c, Connect a dual binding post to BNC Adapter to the
patch cords.
d. Connect a BNC female to BNC female adapter to the
BNC end of the dual binding post to BNC adapter.
e. Connect the Special Input Cable (4 pin connector on
one end and BNC on the other) to the BNC female to BNC
female adapter.
f, Connect the 10 Probe to Input A of the H Plug-In
Unit in the test oscilloscope.
g. Connect the 10X probe tip to the red terminal of the
dual binding post to BNC adapter,
h. Connect the 10% probe ground to the black terminal
of the dual binding post to BNC adapter.
Calibration—Type 2A61
athe 'Piha pene'
+7)
>< > +
Wy 4 Aa
Silvered
Maximum Capacitance
Silvered
Minimum Capacitance
Fig. 6-14. Location of C424 and C524.
Fig. 6-15. Maximum and minimum capacitance settings of C424
ond C524,
i. Adjust the output of the Audio Generator to 5 volts
peak to peak displayed on the test oscilloscope.
j. Preset C424, Fig. 6-14, to maximum capacitance and
C524, Fig. 6-14, to minimum capacitance as shown in Fig.
6-15,
k. Using a non-metallic screwdriver, adjust C424 and C524
for minimum deflection of the Type 561A display,
|. The maximum allowable deflection seen on the Type
561A CRT is two divisions. This corresponds to a 50,000:1
common mode rejection ratio, Any combination of C424 and
C524 settings that achieve the desired results is acceptable.
NOTES
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6-13