Specifications

Chapter 11 99
Demodulating AM and FM Signals
Demodulating an FM Signal Using the ESA-E Series (Requires Option BAA)
Demodulating AM and FM Signals
Press BW/Avg, Res BW, 30, kHz.
Step 7. Turn on the FM demodulator:
Press
Det/Demod, Demod, FM.
Step 8. Change the vertical scaling:
Press
AMPLITUDE Y Scale, Scale/Div, 5, kHz.
Figure 11-4 FM Demodulation (ESG FM Signal with 10 kHz Deviation)
Step 9. Calculate the FM deviation using markers with max hold and min hold
functionality (also note that each division has 5 kHz of FM deviation if
you wanted to visually calculate the deviation):
Press
View/Trace, Max Hold.
Wait until the trace appears to be a flat line before continuing to the
next button sequence below:
Press
Marker, Delta, View/Trace, Min Hold.
The value on the screen from the delta value of max hold and min hold
is the peak-to-peak deviation value. We are interested in the average
value which we can calculate by dividing the peak-to-peak value by 2.
In our case it should be approximately 20 kHz/2 or 10 kHz.