WSJT-X/doc/user_guide/controls-functions-wide-graph.adoc

// Status=review

The following controls appear at the bottom of the Wide Graph window.
With the exception of *JT65 nnnn JT9*, they affect only the graphical
displays — they have no effect on the decoding process.

image::wide-graph-controls.png[align="center",alt="Wide Graph Controls"]

- *Bins/Pixel* controls the displayed frequency resolution.  Set this
value to 1 for the highest possible resolution, or to higher numbers
to compress the spectral display. Normal operation with a convenient
window size works well at 2 to 8 bins per pixel.

- *JT65 nnnn JT9* sets the dividing point (blue marker) for wide-band
decoding of JT65 and JT9 signals in *JT9+JT65* mode.  The decoder
looks for JT65 signals everywhere, but JT9 signals only above this
frequency.

- *Start nnn Hz* sets the low-frequency starting point of the
waterfall frequency scale.

- *N Avg* is the number of successive FFTs to be averaged before
updating the spectral display.  Values around 5 are suitable for
normal JT9 and JT65 operation.  Adjust *N Avg* to make the waterfall
move faster or slower, as desired.

- A dropdown list below the *Palette* label lets you select from a
wide range of waterfall color palettes.  

- Click *Adjust* to activate a window that allows you to create a
user-defined palette.

- Check *Flatten* if you want _WSJT-X_ to compensate for a sloping or
uneven response across the received passband.  For this feature to
work properly, you should restrict the range of displayed frequencies
so that only the active part of the spectrum is shown.

- Select *Current* or *Cumulative* for the spectrum displayed in the
bottom one-third of the Wide Graph window.  *Current* is the average
spectrum over the most recent *N Avg* FFT calculations.  *Cumulative*
is the average spectrum since the start of the present UTC minute.
*Linear Avg* is useful in JT4 mode, especially when short-form
messages are used.

- Four sliders control reference levels and scaling for waterfall
colors and the spectrum plot.  Values around midscale are usually
about right, depending on the input signal level, the chosen palette,
and your own preferences.

- *Smoothing* is active only when *Linear Average* has been selected.
Smoothing the displayed spectrum over more than one bin can enhance
your ability to detect weak EME signals with Doppler spread more than
a few Hz.