GW Instek GRF-1300A - Manual (Page 76)

GRF-1300A User Manual and Teaching Materials
low-pass filter passband to achieve a phase-locked FM wave.
When the center frequency of the VCO is locked on to a stable
high frequency, it allows the VCO to shift in frequency when the
modulating signal is varied.
Figure 6-2.
GRF-1300A
FM principle
Experiment
contents 1. Measure the FM wave spectrum.
2. Observe how the amplitude of the modulating signal affects the
FM wave frequency deviation.
3. Observe how the frequency of the modulating signal affects the
FM wave frequency deviation.
1. Turn on the GRF-1300A and GSP-730.
2. Set the GRF-1300A as follows:
• Under the default state (the state from power-up), turn the
potentiometer to the minimum position.
• Connect the output port on the Baseband module to the FM in
port on the RF Synthesizer/FM module with an RF cable.
• Connect the RF/FM output port to the RF input port on the
spectrum analyzer with an RF cable.
Experiment
steps
3. Set the GSP-730 as follows:
• Center frequency:880MHz
• Span: 50MHz
• Reference level: 0dBm
• RBW: Auto
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