Adjusting The Aberrations For The Edge Function - Fluke 5520A Service Manual

This procedure should only be used for adjusting the leveled sine wave
harmonics. Do not use this procedure as a verification test. The
specifications in this procedure are not valid for verification.
1. Set the Spectrum Analyzer to the parameters listed below.
Spectrum Analyzer Setup
Start Frequency
Stop Frequency
Resolution Bandwidth
Video Bandwidth
Reference Level
2. Use your Spectrum Analyzer's Peak Search function to find the desired reference
signal. The Analyzer should show the fundamental, and second and third harmonics.
The harmonics need to be adjusted so that the second harmonic is at 40 dBc and third
harmonic should typically be at 50 dBc as shown in Figure 6-16.
3. To adjust the harmonics, adjust R8, as shown in Figure 6-16 until the peaks of the
second and third harmonic are at the correct dB level. You may find that you can
place the second harmonic at 40 dBc but the third harmonic is not at 50 dBc. If this 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.
40 dBc
2nd harmonic
Figure 6-16. Adjusting the Leveled Sine Wave Harmonics

6-80. Adjusting the Aberrations for the Edge Function

Adjustments need to be made after repair to the edge function to adjust the edge
aberrations.
Note
50 MHz
500 MHz
3 MHz
3 kHz
20 dBm
50 dBc
3rd harmonic
SC600 Option
SC600 Hardware Adjustments
R8
6
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