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4.4 Setting the Sweep Mode and Sweep Bandwidth (RBW)
This menu group controls the sweep and the resolution bandwidth.
This enables the sweep to be controlled in terms of the type of sweep (repeat or single) and the
resolution bandwidth of the sweep filter and the subsequent video filtering. If option U01 is
fitted, sweep triggering can also be controlled.
4.4.1 RBW
controls the resolution bandwidth of the sweep filter. A narrower RBW provides
greater frequency resolution and lower noise, but increases the sweep time.
Creates a set of bottom-row function keys as follows:
causes the RBW to be automatically changed to suit the frequency span. The RBW
value is displayed at the top of the screen and is preceded by the word Auto.
manually selects a specific RBW value which is displayed at
the top of the screen
4.4.2 Video Filter
controls the video filter. With the video filter On, displayed noise levels are lower,
but signals may be slightly attenuated at narrower RBW settings. Creates a set of
bottom-row function keys as follows:
The status of the video filter is shown at the top of the screen preceded
by the word VidF
.
4.4.3 Sweep
controls how and when the sweep runs. Creates a set of bottom-row function keys
as follows:
causes the sweep to be automatically restarted after the completion of the previous
sweep unless halted by the Sweep Control key (or the Sweep Trigger settings).
enables single sweeps that are commenced by the Sweep Control key (or the
Sweep Trigger settings).
Note that, whenever the sweep is stopped, whether in repeat or single mode, changing the
frequency span or the reference level will re-run the sweep once.
Sweep Trigger is only available with the upgrade option U01 is fitted. It provides a
choice of how the sweep is started or stopped. The trigger source can be manual,
external, or internal from limit lines or patterns. See section 4.4.3.3 for an
explanation of trigger functions.
RBW
Video
Filter
Sweep
Sweep/
BW
RBW
Auto
15kHz
280kHz
1MHz
Video
Filter
On
Off
Sweep
Repeat
Single
Sweep
Trigger