Instructions

Service Information
22
P6021 Instruction M anual
6. Connect the probe to the current probe calibration fixture. Figure 7 shows
the proper probe orientation to the current probe calibration fixture.
Calibration fixture
Probe
Figure 7: Connecting the probe to the calibration fixture
7. The following adjustments affect aberrations and flat-top response:
C13, R10, and R12 of the probe (see Figure 8) and C22, C25, and R36 of the
termination (see F igure 9). To minimize aberrations and achieve the best
flat-top response, the following procedure is recommended. However, these
adjustments interact; you may have to readjust several of them to ensure
minimum aberrations..
a. Adjust R10 and R12 for flat response (see Figure 8). (Controls overshoot
in the first 10 ns time domain.)
b. Adjust C13 for flat response. (Controls slope in first 20 ns.)
c. Adjust R36 for flat response (see Figure 9). (Controls front corner, first
5ns.)
d. Adjust C25 to minimize aberrations in the 10 to 20 ns domain.
e. Adjust C22 to minimize aberrations in the 15 to 25 ns domain.