Tektronix RSA6100A Series, Help Manual

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General Signal Viewing > Common Controls for General
Signal Viewing Displays Traces Tab
Setting Description
Trace Selects a trace. (This setting is not present for every display.)
Show Shows / hides the selected trace.
Detection Sets the Detection method used for the trace. Not available for saved traces. Available
detection methods are +Peak, -Peak, +/-Peak, Avg (VRMS), Sample, CISPR Avg, CISPR
Pk, and CISPR QPk. Not all detection methods are available in all displays.
Function Selects the trace processing method. Available settings are: Normal, Average, Max
Hold, and Min Hold.
Count Sets the number of traces averaged to generate the displayed trace. (Present only when
Function is set to Average, Min Hold, or Max Hold.)
Freeze Halts updates to the selected trace.
Save Trace As Saves the selected trace to a fi le for later recall and analysis.
Show Recalled trace Displays a saved trace instead of a live trace.
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Trace
Available traces for Spectrum are: Trace 1, Trace 2, Trace 3, Math, and Spectrogram. Other displays
support fewer traces. Traces 1-3 are based on the input signal and enable you to display the input signal
using different processing. For example, you could display Trace 1 with Function set to Normal, Trace 2
with Function set to Max Hold and Trace 3 with Function set to Min Hold.
The Math trace is the result of subtracting one trace from another.
The Spectrogram trace applies only to the Spectrum display and is available only if the Spectrogram
display is shown. The Spectrogram trace shows the trace selected in the Spectrogram as a spectrum trace.
Detection
Trace Detection is used to reduce the results of a measurement to the desired number of trace points. For
example, if the maximum number of trace points is 100,000, and a measurement over the selected analysis
length yields 200,000 points, the measurement must decimate these 200,000 trace points by 2 to prevent
exceeding the 100,000 trace point limit. Since only one value can be represented for each trace point, an
algorithm must be used to select (detect) the appropriate value to use.
The results array from an analysis can be detected (or “decimated”) in a variety of ways. The number
of results points produced for each trace point varies with both analysis length and trace length. For
example, the frequency transform used for the Spectrum display produces just one output value for each
desired trace point. In this case, the detection method chosen has no effect, as no decimation is required.
Increasing the Analysis Length (or for the Spectrum display, the Spectrum Length), causes the available
detection method’s output traces to differ from each other because they have a larger set of samples for the
various detection methods to process.
The available detection methods (depending on the display) are:
+Peak – The highest value is selected from the results to be compressed into a trace point.
-Peak – The lowest value is selected from the results to be compressed into a trace point.
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RSA6100A Series Real-Time Spectrum Analyzers Help