DominoEX

Fldigi can operate in the following DominoEX modes:
The sound card sampling rate is 8000 Hz for the 4, 8 and 16 modes.  It is 11025 Hz for the 5, 11 and 22 modes.  This change in sound card sampling rate will be seen in the drop rate on the waterfall.

The modem code for dominoEX uses a wide band multiple frequency detector that can lock on and detect the incoming signal even when badly mistuned.  It also uses AFC to lock on to the IFK tone pairs.  This combination provides signal detection that performs well under conditions of low s/n where it is not easy to locate the signal center point on the waterfall.

The waterfall and digiscope will appear as:



The text displayed in the status area is the secondary text being sent by the transmitting station.  When the keyboard buffer is empty the dominoEX modem transmits text from the secondary text buffer.  Your secondary text buffer can be edited on the DominoEX configuration tab.

The digiscope display is similar to the MFSK and represents the tone pairs moving through the tone filters.  You can also use an alternate digiscope display (left click on the digiscope display area).



In this display mode the red line represents the center of the multiple tone bins that are in the detector.  The dots will be blurry if the AFC is not locked on and become very distinct when AFC lock has been achieved.  The tone dots will move from bottom to top (opposite the direction of the waterfall).

This is the same signal mistuned, but with the AFC locked:



and with the signal badly mistuned, but with the AFC locked:



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