R&S FPC Series User Manual

The Spectrum Application
R&S
®
FPC
128User Manual 1178.4130.02 ─ 07
Note: The distance to the reference marker is by default 3 dB below the reference
marker.
14.10.4 Marker Demodulation
Access: "Mkr" > "Marker Demodulation"
The R&S FPC features an AM and FM demodulator to demodulate and monitor audio
signals. It demodulates the signal at the marker frequency.
You can listen to the demodulated signal with the internal speaker or headphones that
you can connect to the 3.5 mm headphone jack on the front of the R&S FPC.
When demodulating an AM modulated signal, the R&S FPC turns the video voltage
into an audible sound. You should therefore set the reference level to about the level of
the signal that you are demodulating.
If you perform measurements in the time domain, the R&S FPC demodulates continu-
ously. In the frequency domain, you can define a time period the R&S FPC demodu-
lates the signal at the marker frequency. The frequency sweep then stops at the
marker frequency for that time before finishing the sweep.
Remote commands required to configure marker properties:
●
Chapter 19.12.8, "Marker", on page 271
Selecting the demodulation type
1. Press the "Mkr" key to open the marker menu.
2. Select the "Marker Demodulation" menu item to open the marker demodulation
menu.
3. Select the "AM" or the "FM" menu item
The R&S FPC demodulates the signal according to the demodulation scheme you
have selected.
Note: If you turn on the demodulator, the R&S FPC automatically turns off the
noise marker or the frequency counter.
4. Select the "Demodulation Off" menu item to turn off marker demodulation.
Defining the demodulation length
1. Press the "Mkr" key to open the marker menu.
2. Select the "Marker Demodulation" menu item to open the marker demodulation
menu.
3. Select the "Time <x>" menu item.
The R&S FPC opens an input field to define the demodulation time.
4. Enter the demodulation time you want to use.
Note: The range is from 100 ms to 500 s. In the time domain, the R&S FPC
demodulates continuously. The demodulation time has no effect in that case.
Marker Functions

R&S FPC Series Specifications

General

Brand	R&S
Model	FPC Series
Category	Measuring Instruments
Language	English