Fluke 5820A, Service Manual

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Options
GHz Module
5
5-9
Level I
yu003.eps
Figure 5-5. Critically Triggered Edge at Porch Height Level I
16. Adjust R175 to reduce the porch level, setting it in the middle of Level I and Level
II.
17. Adjust the vertical/horizontal settings of the oscilloscope so that an entire fast edge
waveform can be viewed. It should look like the waveform in Figure 5-2.
Level I
Level II
yu004f.eps
Figure 5-6. Critically Distorted Edge at Porch Height Level II
18. Verify that the edge rise time is < 150 ps at the cable-end and that the amplitude
from the porch to the top of the edge is ~ 250 mV.
5-10. GHz Leveled Sine Wave Frequency Verification
This procedure uses the following equipment:
•
PM 6680 Frequency Counter with a prescaler for the Channel C input
(Option PM 9621, PM 9624, or PM 9625) and ovenized timebase (Option PM 9690
or PM 9691)