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96
FieldFox User’s Guide
Resolution Bandwidth (Res BW)
In SA Mode, the Res BW provides the ability to resolve, or see closely spaced
signals. The narrower (lower) the Res BW, the better the spectrum analyzer can
resolve signals. In addition, as the Res BW is narrowed, less noise is measured by
the spectrum analyzer ADC and the noise floor on the display lowers as a result.
This allows low level signals to be seen and measured. However, as the Res BW is
narrowed, the sweep speed becomes slower. See Very Long Sweep Times on
page
How to set Res BW
Press
BW 2
.
Then
Res BW
Then choose from the following:
o
Auto
Res BW is coupled to the frequency span. As the frequency span is
narrowed, the Res BW is also narrowed providing increased ability to
resolve signals.
To change this setting from
Man
to
Auto
, press
Res BW
twice.
o
Man
Enter a Res BW value using the numeric keypad, the
▲|▼
arrows, or
the rotary knob. Then press a multiplier if necessary or press
Enter
.
The current Res BW setting is shown at the bottom of the screen.
#Res BW x.xx XHz
( # )
means manual setting.
This setting could impact the accuracy of the measurement. See Specifications on
page 232.
NOTE
The Res BW setting also affects the Sweep Type setting. Learn how on page 97
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
Press
BW 2
.
Then
Video BW
Then choose from the following:.
o
Auto
Couples Video BW to the ResBW in a 1-to-1 ratio.
o
Man
Enter a Video BW value using the numeric keypad, the
▲|▼
arrows,
or the rotary knob. Then press a multiplier if necessary or press
Enter
.
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.