Teledyne LeCroy AP033 - Manual (Page 51)

Operator’s Manual
922260-00 Rev A 45
6. Record the DMM reading. Be careful not to alter the output amplitude of the generator after
the measured value has been recorded.
7. Remove the banana plug adapter and connect the free end of the cable to the Differential
Drive no Termination connector on the calibration fixture.
8. Connect the AP033 Output cable with 50 Ω precision termination to the DMM.
9. Adjust GAIN (R322C) so that the DMM reading is within ±1 mV (0.5%) of the reading recorded
in step F-6. (See Figure 11.)
10. Set AP033 Attenuation/Gain to Manual, Probe Gain to X10, and Probe Atten to /10.
11. Verify that the DMM reads within 1 mV of the reading recorded in step F-6. If the error exceeds
1 mV, readjust GAIN (R322C) for an error amplitude of ½ of the value before making the
readjustment. Compromise as necessary to center the error voltage in both gain/attenuation
combinations, making sure that the final errors are less than 1 mV.
12. Disconnect the Function Generator, DMM, calibration fixture, and precision 50 Ω terminator.
G. Adjust Final Attenuator Compensation (C17)
NOTE: The calibrator signal from a Teledyne LeCroy oscilloscope is the recommended signal source
for this adjustment. If another oscilloscope is being used for this procedure, make sure that the
square wave source has adequate flatness (minimum overshoot and undershoot.)
1. Press the UTILITIES button, then select the CAL BNC Setup menu. Set the Mode to CAL signal,
the Shape to Square, the Amplitude to 1 V into 1 M Ω, and the Frequency to 1 kHz.
2. On the Channel 1, set AP033 Attenuation/Gain to Manual, Probe Attenuation to /10, and Probe
Gain to X10.
3. Reconnect the free end of the ProBus Extender BNC cable to the oscilloscope end of the
extender located on channel 1.
4. Connect a BNC cable from the CAL output BNC connector to the Differential Drive 50 Ohm
Termination connector on the AP033/AP034 Calibration Fixture.
5. Carefully attach the Differential Drive 50 Ohm Termination portion of the AP033/AP034
Calibration Fixture to the probe tip. Press the probe into the fixture to fully engage the pins.
6. Set the oscilloscope’s channel 1 vertical scale factor to 50 mV/div, and the horizontal scale to 1
μs/div. Set the trigger source to channel 1, and Slope to Positive. Adjust the oscilloscope trigger
level as necessary for a stable display.
7. Using the OFFSET knob move the trace down until the top portion of the waveform is centered.
8. Adjust Attenuator Comp (C17A) for a flattop waveform. See Figure 10 for adjustment location.