LeCroy AP034, Instruction Manual

Page: 60 / 76

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ISSUED: January 2000 AP034-OM-E Rev D
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5. Set the oscilloscope as follows:
Display: Channel 2
Channel 1 VOLTS/DIV: 2 mV/div
Channel 2 VOLTS/DIV: 5 V/div
Channel 2 Coupling:
'&0
Channel 3 VOLTS/DIV: 2 mV/div
Channel 3 Coupling: AC 1M
Ÿ
Trigger on: EXT10
cplg EXT10: DC
TIME/DIV: 10 ms/div
Acquisition Mode: NORMAL
6. Adjust the trigger level for a stable display.
7. Set the Function Generator output voltage to 20 V
p-p
as
displayed on the oscilloscope.
8. Disconnect the output cable of the function generator from
the channel 2 input of the oscilloscope and reconnect it to
the Common Mode Drive No Termination connector of
the AP033/AP034 Calibration Fixture.
9. Carefully align the four pins that correspond to the
Common Mode Drive No Termination portion of the
AP033/AP034 Calibration Fixture with the input receptacles
in the AP034 probe head. Press the probe into the fixture to
fully engage the pins.
10. Set the oscilloscope to display channel 3. The waveform is
the common mode signal. Turn the offset as necessary to
keep the trace on screen. Turn on Math Channel A. Press
MATH SETUP, then REDEFINE A. Set the A Math type to
Average, Avg Type to Continuous, with 1:15 weighting,
of channel 3. Turn off the trace 3 display. Use the Math
Zoom and Position controls as necessary to view the
waveform.
11. Adjust LF CMRR (R7) for minimum amplitude. (See Figure
12 for location.)