Adjusting The Leveled Sine Wave Vco Balance; Adjusting The Leveled Sine Wave Harmonics - Fluke 5520A Service Manual

5520A
Service Manual
Refer to Figure 6-9 for setup connections and connect the Calibrator Mainframe to the
Spectrum Analyzer. Adjust the Spectrum Analyzer so that it displays one peak across its
horizontal center line. The far right of the peak is fixed at the far right of the center line,
as shown below.

6-78. Adjusting the Leveled Sine Wave VCO Balance

Once you have completed the setup described above, perform the following procedure to
adjust the VCO balance for the leveled sine wave function.
1. Program the Calibrator Mainframe for an output of 5.5 V @ 600 MHz.
2. Set the Spectrum Analyzer to the parameters listed below.
3. You need to adjust the wave until the spur is at a minimum. To do this, slowly rotate

6-79. Adjusting the Leveled Sine Wave Harmonics

The following procedure adjusts the harmonics for the leveled sine wave function.
6-58
Spectrum Analyzer Setup
Start Frequency
Stop Frequency
Resolution Bandwidth
Video Bandwidth
Reference Level
The Spectrum Analyzer will display a spur at 153 MHz. Refer to Figure 6-15 to
identify the spur.
R1 (shown in the diagram) counterclockwise until the spur is at a minimum. As you
adjust it, the spur will move down the waveform, towards the right. As soon as the
spur is minimized, stop rotating R1. If you rotate it too far, the spur will reappear.
Once you have turned R1 to the point at which the spur is at a minimum, the signal is
balanced between the VCOs, and you have completed the adjustment.
Figure 6-15. Adjusting the Leveled Sine Wave Balance
10 MHz
800 MHz
30 kHz
3 kHz
20 dBm
R1
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