Agilent Technologies N9342C, Руководство пользователя

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Functions and Measurements 3
N9342C/43C/44C User’s Guide 63
Demodulating an FM Signal
This section demonstrates how to demodulate and
listen to an FM signal using the built- in FM
demodulator.
Using the built- in FM demodulator you can tune to
an FM signal and view the results of the detector
output as displayed in the time- domain.
Alternatively, the demodulated signal is also
available as an audio output (to the speaker or
headphone jack).
1
Perform a factory preset:
Press
[Preset]
(factory preset)
.
2
Use a signal source or an antenna for an FM
signal to analyze. In this example the signal
source is used transmitting at 300 MHz with FM
deviation of 10 kHz and FM rate of 1 kHz.
3
Set the center frequency to the center of the FM
signal (in this case 300 MHz):
Press
[
FREQ] > 300 > {MHz}
.
4
Set the analyzer to zero span for time- domain
analysis:
Press
[SPAN] > {Zero Span}
.
Press
[Sweep] > { Sweep Time} > 4 > {ms}
.
5
Turn off the input attenuation and turn on the
optional pre- amplifier:
Press
[AMPTD] > {Attenuation} > 0 > {dB}
.
Press
{Preamp On}
NOTE
If you are using a broadcast FM signal in the United States,
for example, the FM channels are broadcasting between
87.7 MHz to 107.7 MHz. The optional preamplifier is essential
for the broadcast FM signal demodulation.