Agilent Technologies ESA Series User's/Programmer's Reference page 70

Front-Panel Key Reference
Det/Demod
The
NOTE
hardware is installed (options 106, AYQ or BAA). If you have multiple
FM demodulation hardware options, the hardware that will be used is
automatically selected in order of priority. (With firmware revision
A.14.00 or later.)
1. Option 106 - Bluetooth 
2. Option AYQ - Quasi-peak detection and FM demodulation
3. Option BAA - FM Demodulation
Segmented sweep is not available with the demodulation functions in
NOTE
this section.
Off
AM
FM
70
menu key only appears when the optional FM demodulation
FM
Turns demodulation off.
Key Access:
Activating AM demodulation turns off FM
demodulation (if it is on). For non-zero spans, a 10 kHz
resolution bandwidth is used during demodulation,
regardless of the screen annotation. When the span is
set to zero span, the displayed bandwidth is used.
Key Access:
Turning FM demodulation on turns off AM
demodulation (if it is on). For non-zero spans, a
100 kHz resolution bandwidth is used during the
demodulation, regardless of the screen annotation.
When the span is set to zero span, the displayed
bandwidth is used. For best results, move the signal to
be demodulated to within 3 divisions of the top of the
display.
Follow these steps to use this key:
1. Turn auto align off. (
)
Off
2. Calibrate the demodulator. (
Align Now
3. Set the center frequency. (
4. Go to zero span. (
5. Set the resolution bandwidth. (
Res BW
6. Set the detector to sample. (
)
Sample
7. View the FM demodulation. (
Demod View
8. Use the Markers to measure the FM demodulation
and the modulation rate. (
9. Adjust the sweep time as necessary.
,
Det/Demod Demod
,
Det/Demod Demod
,
System Alignments
System
,
FM Demod)
FREQUENCY)
,
SPAN Zero Span)
)
Det/Demod
Det/Demod
(On))
Marker
, ,
Auto Align
, ,
Alignments
,
BW/Avg
, ,
Detector
, ,
Demod FM,
)
Chapter 2