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6 Common Functions
120
IDA - 3106 Narda
6.13.3 Starting demodulation (Spectrum only)
Spectrum • Audio
You can start demodulation of the signal at the actual marker position in
Spectrum
mode. The sweep is paused while demodulation is taking place.
You can switch between demodulation and sweep manually or
automatically. The duration of demodulation can be selected using the
Dwell Time
softkey. The demodulation frequency can be tuned at any time
by adjusting the marker position. The demodulation bandwidth can be set
independently from the resolution bandwidth of the measured spectrum.
To start demodulation:
1.
Press the
Audio
softkey.

The selection window for choosing the demodulation type opens.

If a demodulation type is already selected, go to step 3.
2.
Use the rotary control knob to select the desired demodulation type and
press
OK
to confirm.

If a marker is not displayed, it will be activated automatically. The
measurement traces are frozen and the signal at the marker position
is demodulated (adjust the volume if necessary).
Demodulating
is displayed at the lower right of the measurement
screen.
3.
Press the
Demod. Bandwidth
softkey to adjust the bandwidth.

The selection window opens and displays Coupled to RBW (… Hz).
The demodulation bandwidth used is shown in brackets.
4.
Press the
Start/Stop Demodulation
softkey to switch between
measurement and demodulation.
– or –
Press the
decimal point
key of the number keys.
5.
To stop demodulation:
Press the
Demodulation
softkey, select
Off
with the rotary control knob
and press
OK
to confirm.
NOTE: Dwell Time
is set to
manual
by default. You can also set a value here
between 1 s and 30 s to enable automatic switching between demodulation
and sweep.
Demod. Bandwidth
is set to
Coupled to RBW
by default and limits the
demodulation bandwidth to permissible values automatically. You can also
set a fixed value.
Demodulation can also be used after exiting from the Audio menu. If you
want to do this, use the
decimal point
key of the number keys to interrupt
demodulation.