FLDIGI Users Manual 3.21
The first time you execute fldigi you should resize the main window to suit your screen dimensions. Then adjust the divider line between the Rx and Tx text widgets..
Fldigi contains many configurable items, to specify operator data, user interface, and modem characteristics. The application also saves many state variables between executions. It will start up in the state that it was last used.
You should initially configure the following:
When the program receives and transmits digital signals and your rig control is satisfactory then you can continue configuring other aspects of the program:
Additional configurational items are available from the command line.
See Command Line Switches for details.
You can configure each modem type to suit your particular operating needs, but the defaults should be satisfactory for most users.
When you have completed the configuration go to the Configure menu and select Save config or press the "Save Config" button on the configure dialog box. The program will write the file ~/.fldigi/fldigi_def.xml.