Am/Fm Audio Demodulation - JDS Uniphase CellAdvisor JD700B Series User Manual

Chapter 4 Using Spectrum Analyzer
Measurement example
Figure 15 Spurious emissions measurement with spectrum analyzer

AM/FM audio demodulation

The AM/FM Audio Demodulator operates using the power received from radio waves and it serves as
an alternative to identify interfering signals easily. The instrument sounds demodulated signals that
can be heard through the built-in speaker or plugged-in headphones. You can hear the sound and
identify interfering signals easily.
Setting measure setup
After configuring test parameters as described in the "Configuring test parameters" on page 54, you
can set the measure setup to continue your measurement. The measurement settings can be saved
and recalled as a file. You can also use JDViewer, PC application software to configure a measure
setup, save as a file, and load the file on to the instrument.
Procedure
1
Press the MEASURE SETUP hot key.
2
Toggle the Audio Demod soft key between On and Off to turn the AM/FM audio demodulation
on and off.
3
Press the Demod at soft key, and then select the marker number for the frequency to be
demodulated.
NOTE
You must set the marker(s) first by using the MARKER hard key as the AM/FM
demodulator uses the marker position to demodulate. See "Using marker" on page 49 for
more information.
4
Press the Demod Mode soft key, and then select the demodulation mode: AM, FM and CW.
5
Press the Dwell Time soft key, and then turn the rotary knob to set the demodulation interval
between 1 and 20.
6
Press the Volume soft key, and then turn the rotary knob to set the speaker volume.
7
Toggle the Auto Gain soft key between On and Off to enable or disable the automatic gain
feature to adjust the interval gain of the demodulator.
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JD700B Series User's Guide