Manual
AP034 Active Differential Probe
38 922261-00 Rev A
Procedure
A. Adjust Coarse DC Balance (R226)
1. If necessary, set the probe offset to 0.000 V by rotating the OFFSET knob in the CHANNEL
section of the oscilloscope.
2. Insert the two-pin shorting plug into the socket on the Logic Board. Use the two holes
closest to the probe cable (Figure 9).
Figure 8, AP033 Logic Board
3. To enter the Cal Mode, push either of the two offset buttons that protrude through holes in
the Logic Board.
4. Plug the precision 50Ω terminator into the DMM input. Set the DMM to measure DC volts.
5. Using a low capacitance screwdriver, adjust Coarse DC Bal (R226) on the Amplifier Board
for an output voltage of 0 mV ±10 mV (Figure 10).
Figure 9, Amplifier Board Adjustment Locations