190 Chapter 2
Front-Panel Key Reference
Sweep
Sweep
Activates the sweep time function and accesses the following menu
keys:
Sweep Time
Auto Man
Selects the length of time the analyzer takes to tune across the
displayed frequency span (or, in zero span, the time the analyzer takes
to sweep the full screen). Reducing the sweep time increases the sweep
rate. The sweep time can be changed using the step keys, the knob, or
the numeric keypad.
In non-zero spans:
When the sweep time is auto-coupled, the analyzer selects the optimum
(shortest) sweep time for the current settings. This selection process is
influenced by several factors:
• The maximum tuning rate of the spectrum analyzer
• The selected Resolution Bandwidth and Video Bandwidth filters
• The maximum sample rate of the Analog-to-Digital converter (ADC)
(Trace data are digitized and stored in memory)
• The number of trace points (
Sweep, Points)
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.
In zero span:
The minimum sweep time is determined by the maximum sample rate
of the ADC and the number of sweep points. With Option AYX, the
fastest sweep time is 5 microseconds (with 101 sweep points). Without
the option installed, the fastest sweep time is 1 millisecond (with 101
sweep points) and 4 milliseconds (with 401 sweep points).
NOTE With firmware A.08.00 and greater, in zero span, 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.
The maximum sweep time is 4000 seconds for any set of conditions.
Refer to your instrument’s appropriate Specifications Guide for more
information about Sweep Time and its relation to other instrument
settings.
Key Access:
Sweep