12
Operating the Probe
Recommended Test Equipment
Offset null zeroes the dc level at the output of the probe. The range of adjustment is
about ±4 mV.
DC Reject Gain adjusts the gain of the dc reject circuit to accurately null the dc
component of an input signal. The range of adjustment is about ±0.5%.
Figure 1-5
1142A Front Panel
Equipment Needed
The following equipment is necessary for initial adjustment.
5 V power supply
DVM that can measure 25 µV
•50 BNC feedthrough terminator
01141-66504 test board
Equipment Setup
Use the following procedure to setup the differential probe system for initial adjustment.
CAUTION Do not exceed ±7 V when using the test board for this procedure. If the voltage is too
high, it will cause excessive power dissipation in the 50 termination on the test board.
1Use the probe setup procedure to set up the probe system.
2Connect a 50 BNC feedthrough terminator to the output of the probe.
3Disconnect all accessories from the input of the probe.
4Connect the DVM to measure the dc output of the probe at the 50 load.