Fluke 5500A, Service Manual

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5500A
Service Manual
6-114
5. Readjust A90R36 to center the first two aberrations about reference level.
6. Readjust A90R13 if necessary to keep the edge signal at 10 ns to be at the reference
level.
7. Readjust A90R36 ,A90R35 or A90R12 to obtain equal amplitudes of the aberrations
displayed during the first 10 ns to be equally above and below the reference level. Check
the aberrations , compare with specifications. It may be necessary to slow the rise
time(A90R35) to reduce the amplitude of the aberrations.
8. Set the UUT output to 2.5 V and the oscilloscope vertical to 2 mV/div. Check the
aberrations.
9. Remove the 20 dB attenuator from the oscilloscope input. Connect the UUT to the scope
input and program the UUT output to 250 mV.
10. Set the oscilloscope vertical to 5 mV/div. Check the aberrations.
11. Check for rise time < 950 ps
±
25 ps at 250 mV, 1 V, and 2.5 V outputs.
R36
R12
R13
R35 T
1st Aberration
2nd Aberration
3rd Aberration
om050f.eps
Figure 6-30. Adjusting Edge Aberrations