Keysight Technologies N9321C User Manual page 116

Key Reference
BW
BW
108
This hardkey activates the resolution bandwidth function and
accesses the softkey menus that control the bandwidth and
averaging functions.
Res BW
controls the 3 dB resolution bandwidth of the analyzer from 10 Hz
Auto Man
to 3 MHz using the knob or arrow keys. There are four available
bandwidths less than 1 kHz are 10, 30, 100 Hz or 300 Hz. If an
invalid bandwidth is entered using the numeric keypad, the
analyzer chooses the closest acceptable bandwidth. As the
resolution bandwidth is decreased, the sweep time is modified in
order to maintain amplitude accuracy. Resolution bandwidth is
also coordinated with the frequency span. As the span is
decreased, the resolution bandwidth decreases. When the
VBW/RBW is set to AUTO, if the resolution bandwidth changes, the
video bandwidth changes to maintain the VBW/RBW ratio.
A "#" mark appears next to "Res BW" on the display when it is not
coupled. To recouple the resolution bandwidth, press Res BW
(Auto).
Key access: BW > RBW
Video BW
changes the analyzer post-detection filter from 1 Hz to 3 MHz
Auto Man
using the knob or arrow keys. If an invalid bandwidth is entered,
the analyzer chooses the closest available bandwidth. As the video
bandwidth decreases, the sweep time will increase to maintain
amplitude accuracy.
A "#" mark appears next to "VBW" on the bottom of the analyzer
display when it is not coupled. To couple the video bandwidth,
press Video BW (Auto).
Key access: BW > VBW
VBW/RBW
Sets the ratio between the video and resolution bandwidths. When
Auto Man
a signal is weak and is visually masked by the noise floor, set the
ratio to less than 1 to lower the noise. When the Preset Type is set
to Factory and Preset is pressed, the ratio is set to 1. Change the