WSJT-X/doc/user_guide/en/tutorial-example6.adoc

FST4W is used in the same way as WSPR, but FST4W has significant
advantages for use on the 2200 m and 630 m bands.  By default the
central *Rx Freq* is 1500 Hz and *F Tol* is 100 Hz, so the active
decoding range is 1400 to 1600 Hz.  However, for added flexibility you
can select different center frequencies and *F Tol* values.  We expect
that usage conventions will soon be established for FST4W activity on
2200 and 630 m.

A new drop-down control below *F Tol* offers a round-robin mode for
scheduling FST4W transmissions:

image::FST4W_RoundRobin.png[align="center"]

If three operators agree in advance to select the options *1/3*,
*2/3*, and *3/3*, for example, their FST4W transmissions will occur in
a fixed sequence with no two stations transmitting simultaneously.
Sequence 1 is the first sequence after 00:00 UTC.  For WSPR-like
scheduling behavior, you should select *Random* with this control.

.Open a Wave File:

- Select *FST4W* on the *Mode* menu. Set *T/R* to 1800 s and *Decode | Deep*.
- Set *NB* to 0%.
- Select appropriate wide graph settings. For example, try *Bins/Pixel* 1, 
*Start* 1200 Hz and *N Avg* 150. 
- Open a sample Wave file using *File | Open* and select the file
...\save\samples\FST4+FST4W\201230_0300.wav. 
When it is finished you should see a single decode as shown in the 
screenshot:

image::FST4W-1.png[align="left"]

Note that the weak signal associated with the single decode is all but invisible on the 
widegraph spectrogram.