Instructions

AP033 Active Differential Probe

Procedure

NOTE: This procedure must be performed with the probe set to Manual gain control. See

Operating with Teledyne LeCroy Oscilloscopes on page 13 for more information about

controlling probe settings in different software versions.

A. Adjust Preliminary Probe DC Balance (R36)

1. From the oscilloscope’s front panel, select Channel 1. Set probe Gain Control to

Manual, Attenuation to ÷10, and Gain to X10.

2. If necessary, set the probe offset to 0.000 V.

3. Connect one end of a BNC cable to the probe end of the ProBus Extension Cable.

Attach the precision 50 Ω terminator to the opposite end of the BNC cable.

4. Insert the banana plugs of the precision 50 Ω terminator into the input terminals of

the DMM.

5. Insert the two pin shorting plug into the socket on the Logic board. Use the two holes

closest to the probe cable. (See Figure 8).

Figure 9, AP033 Logic Board

6. To enter the Cal Mode, push any one of the four buttons that protrude

through holes in the Logic board. Entry into Cal Mode is confirmed by the

absence of an audible “click” when you push the button.

7. Adjust DC Bal (R36) on the probe tip (Figure 9) to obtain a DMM reading of 0 V ±10

mV.

NOTE: This voltage may not be stable because of air currents near the probe. The

average voltage should be 0 V ±10 mV.