Freedom R8100 SERIES, Operator'S Manual

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is inhibited at spans above 158 kHz. Switch display to Mod Scope or use Demod at Marker function to
hear audio at wider spans.
Start Frequency
Sets the display start frequency in MHz. Use with the Stop Frequency to establish a desired frequency
range for the Spectrum Analyzer display. The R8100 automatically centers the frequency display midway
between Start and Stop frequencies.
Stop Frequency
Sets the display stop frequency in MHz. Use with the Start Frequency to establish a desired frequency
range for the Spectrum Analyzer display. The R8100 automatically centers the frequency display midway
between Start and Stop frequencies
Reference Level
Adjusts the maximum level for the vertical scale of the display (top line) from -120 dBm to +60 dBm in
1 dB increments.
Vertical Scale
Selects the vertical scale resolution for the display’s major grid lines from 1 dB/div to 10 dB/div via a
horizontal soft key list.
Display Mode
Selects the display presentation with the following horizontal menu choices:
Normal – The display updates continuously.
Freeze – Provides a snapshot of the current display indication and stops additional updates. Note: In
Freeze mode the R8100 reacquires data and updates the display whenever “Center Marker” or “Center
Peak” is pressed.
Max Hold – The display retains the highest peak signal amplitudes measured during successive sweeps.
Average – The displayed signal amplitudes are a rolling average of the peak amplitudes measured on each
successive sweep. The average consists of 1 to 5 sweeps, shown beside the mode indication.
Trace Math
Selects an equation to use for the computation of the spectrum trace (white) from the Display Mode trace
and reference trace (cyan). Setting Display Mode to Average minimizes effects of a low level / high
variance signal such as the noise floor. Note: The underlying units of the result are no longer dBm but dB
for the displayed spectrum and thus marker power.
The following are horizontal menu choices.
None – Hides the reference trace and displays the spectrum resulting from the Display Mode unmodified.
Spec-Ref (log) – Displays the difference of the Display Mode spectrum in dBm minus the reference trace
in dBm, which normalizes the spectrum to 0 on the Y-axis. Subsequently, spectrum power is shown on
the display and measured by absolute markers relative to the reference trace, i.e. correctly interpreted as
dBm above the reference.