Video Bandwidth; Sweep Type - Agilent Technologies FieldFox N9912A User Manual

#Res BW x.xx XHz ( # ) means manual setting.
This setting could impact the accuracy of the measurement. See Specifications on
page 160.
NOTE The Res BW setting also affects the Sweep Type setting. Learn how on page 73
Video Bandwidth (Video BW)
Video BW is a smoothing operation that is performed after measurement data is
acquired. The trace data is effectively smoothed so that the average power level
of the displayed noise is the same, but the peaks and valleys of adjacent data
points are smoothed together. More smoothing occurs as the Video BW is set
lower. However, as the Video BW is narrowed, the sweep speed becomes slower.
How to set VBW

 Then
NOTE To change this setting from Man to Auto, press Video BW twice.
The current Video BW setting is shown at the bottom of the screen.
# VBW x.xx XHz ( # ) means manual setting.
When the Res BW/Video BW ratio exceeds 10,000, a
appear to indicate that the Video BW filter has reached the maximum capacity
for averaging.
In Zero Span, the maximum Res BW/ Video BW ratio is 100.

Sweep Type

In SA mode, the FieldFox uses two sweep types to process inputs signals. The
sweep type that is currently being used (FFT or Step) is displayed in the lower-
left corner of the FieldFox screen.
For a more comprehensive tutorial, see Spectrum Analysis Basics (App Note 150)
at
How to set Sweep Type


 Then
SA (Spectrum Analyzer) Mode
Press BW 2.
Video BW Auto Man.
Auto Couples Video BW to the ResBW in a 1-to-1 ratio.
o
Enter a Video BW value using the numeric keypad, the ▲|▼ arrows,
Man
o
or the rotary knob. Then press a multiplier if necessary or press Enter.
http://cp.literature.agilent.com/litweb/pdf/5952-0292.pdf
Press BW 2.
Then
Advanced
Sweep Type Auto FFT Step
The FieldFox selects the most efficient sweep type based on the Res
Auto
o
BW. When Res BW is set to 200 kHz and below, FFT sweep type is selected.
Above 200 kHz, and Step sweep type is being performed.
FFT The FieldFox uses FFT sweep type regardless of the Res BW.
o
warning may
Meas UNCAL
73