Specifications

Using the Markers R&S FSH
1145.5973.12 4.34 E-10
AF demodulation
The R&S FSH has an AM and FM demodulator for audiomonitoring signals. The demodulated AF signal
can be listened to with headphones (supplied accessories). The headphones are connected to the
3.5 mm jack on the left-hand side of the carrying handle. As the R&S FSH makes the uncontrolled video
voltage audible in the case of AM demodulation, it is advisable to set the reference level so that the
level of the signal to be demodulated is near the reference level.
When spectrum measurements are being made, the R&S FSH demodulates the signal at the marker
frequency for a settable period of time. The sweep stops at the marker frequency for the demodulation
period and then continues. If time-domain measurements are being made (span = 0 Hz), the R&S FSH
performs continuous demodulation.
Operating sequence:
¾ Press the MARKER key.
¾ Press the MARKER DEMOD softkey.
The submenu for setting demodulation parameters
opens. If no markers have been activated, the
R&S FSH automatically turns on the marker and
positions it on the trace maximum.
¾ Using the cursor keys or the rotary knob, select the
demodulation mode (AM or FM) you want and
confirm your selection with the ENTER key.
Note: When the AF demodulation mode is
selected, the R&S FSH automatically
turns off the noise marker or the
frequency counter.
¾ To enter the demodulation time, select the TIME... item in the menu.
The currently set demodulation time is displayed in the value entry box. The demodulation time range is
100 ms to 500 s. If the R&S FSH is set to span = 0 Hz, the demodulation time setting is irrelevant as
continuous demodulation is always performed.
¾ Change the time with the cursor keys or the rotary knob or enter a time using the number keys and
confirm with the ENTER key.
¾ To adjust the volume, select the VOLUME... menu item and confirm your selection with the ENTER
key.
The R&S FSH displays the volume in % in the value entry box. The volume range is 0 % (very low) to
100 % (full volume).
¾ Using the cursor keys or the rotary knob, adjust the volume or enter the volume in % using the
number keys and confirm with the ENTER key.
To indicate that AF demodulation is on, the softkey label MARKER DEMOD is highlighted in green
when you quit the submenu.