Fluke 5500A, Service Manual

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SC300 Option
SC300 Hardware Adjustments for the A4 Board
6
6-117
is the case, continue adjusting R8. The second harmonic will fluctuate, but there is a
point at which both harmonics will be at the correct decibel level.
R57
R16
R1
R8
R168
40 dBc
50 dBc
2nd harmonic
3rd harmonic
om038f.eps
Figure 6-32. Adjusting the Leveled Sine Wave Harmonics
6-150. Adjusting the Aberrations for the Edge Function
Adjustments need to be made after repair to the edge function to adjust the edge
aberrations. There are two SC300 boards currently available, and each requires separate
aberration adjustment procedures; thus certain procedure headings include specific part
numbers. The two boards are listed below. Check the part number of your board before
you begin aberration adjustments. If you are not certain which board you have, contact
your Fluke Service Center.
•
SC300 Board 5500A-4004-1 (Fluke PN 600749)
•
SC300 Board 5500A-4004 (Fluke PN 937383)
Note
To verify the edge aberrations back to national standards, you should send
your Calibrator Mainframe to Fluke, or other facility that has established
traceability for aberrations. Fluke, for example, has a reference pulse that
is sent to the National Institute of Standards and Technology (NIST) for
characterization. This information is then transferred to high speed
sampling heads, which are used to adjust and verify the SC300.
6-151. Equipment Setup
Program the Calibrator Mainframe to output 1V p-p @ 100 kHz. Set the Trigger to /1.
Using the 60 ns Delay Cable, connect the SCOPE output of the Calibrator Mainframe to
the SD-22 sampling head on the oscilloscope. Connect the trigger output to the 11801B’s
trigger input. Then set the sampling heads to the settings listed below, to establish a
reference signal.
In addition to the settings shown below, adjust the scan control for a well-triggered
display. (You may need to adjust the signal averaging on the 11801B.)