WSJT-X/doc/user_guide/en/tutorial-wide-graph-settings.adoc

// Status=review

The WSJT-X Wide Graph window displays the frequency spectrum of the received audio. Usually, the 
upper portion of the window shows a waterfall plot of the frequency spectrum (a spectrogram) and 
a line plot of the current or average spectrum. Controls at the bottom of the window are used to 
set up the displayed audio frequency range, color palette, and scaling of the spectrum displays. 
A control on the bottom right of the Wide Graph (displayed as *Spec nn%*) lets you control
the vertical fraction of the window occupied by the spectrum line plot.
It is important to set appropriate lower and upper 
audio frequency limits for the Wide Graph because these limits define the FT8 decoder's search window.
For this tutorial, the limits will be set to cover 100-3300 Hz:

- Set *Start* = 100 Hz.
- Set *Bins/Pixel* = 5. Smaller/larger values make the Wide Graph cover a smaller/larger 
frequency range.
- Use the mouse to grab the left or right edge of the *Wide Graph*, and
adjust its width so that the upper frequency limit is about 3300 Hz.

The *N Avg* setting controls how many spectra are averaged to produce each line in the spectrogram. 
Smaller values make the spectrogram update more frequently, resulting in signals being more spread
out in the vertical (time) direction.
On the other hand, larger values make it easier to detect very weak signals:

- Set *N Avg* = 2. 

The *Palette* setting controls the color scheme used for the spectrogram: 

- Set *Palette* = Fldigi 

When *Flatten* is checked, WSJT-X attempts to correct for slope or curvature in the receiver's
passband shape.  

- *Flatten* = checked 

The line plot can be set to display the current (un-averaged) spectrum or the cumulative (averaged)
spectrum:

- Select *Cumulative* for data display
- Set the *Gain* and *Zero* sliders for the waterfall and spectrum to near midscale

The *Spec nn%* setting determines what fraction of the vertical extent of the Wide Graph will
be used for the line plot of the spectrum. Setting *Spec* to 0 will eliminate the line plot and
a setting of 100 will eliminate the spectrogram and show only the line plot:

- Set *Spec* = 50%