User Manual

Chapter 4 241
Instrument Functions: P - Z
SWEEP
Instrument Functions: P - Z
4.7 SWEEP
Activates the Sweep Time function and displays the sweep function menu keys.
Key Path: Front-panel key
4.7.1 Sweep Time
Selects the length of time in which the spectrum analyzer sweeps the displayed frequency
span. In swept spans, the sweep time varies from 1 millisecond to 2000 seconds plus time
for setup which is not calculated as part of the sweep time. Reducing the sweep time
increases the rate of sweeps. In zero span, the sweep time may be set from 1 µsto6000s.
In FFT spans, the sweep time is not controlled by the user, but is an estimate of the time
required to make FFT measurements. Sweep time is coupled to RBW and VBW, so
changing those parameters may change the sweep time. When the analyzer has been set to
FFT, Sweep Time,andAuto Sweep Time are disabled (greyed out).
You may select a sweep time less than the auto-coupled value; however this may generate
measurement errors. If this happens, the error message: Meas Uncal will appear in the
upper right corner of the display.
NOTE In zero span or FFT sweeps, the auto/manual function of this key is not
applicable. When
Sweep Time (Auto) is selected in non-zero span, any changes to
Sweep Time while in zero span will revert to the Auto value when you return
to non-zero span. When Sweep Time (Man) is selected in non-zero span, any
changes to Sweep Time while in zero span will be maintained when you
return to non-zero span (within the available sweep time range). When
entering zero span from a non-zero span, the sweep time does not change.
Key Path:
Sweep
Annunciation/
Annotation: The sweep is displayed in the lower-right corner of the screen. Also, the
points displayed parenthetically.
State Saved: Saved in Instrument State
Factory Preset: Auto
Model Sweep Time
E4440A 66.24 ms
E4443A 11.16 ms
E4445A 22.00 ms
E4446A 110.00 ms
E4448A 125.00 ms