MFSK (MFSK16/32)
A text mode using many tones, able to send text and small images.
ModeMFSK
FamilyMultitone data
Audio example12 s
What does it sound like?
Plate 35Multitone data
A rapid, bubbling series of pure tones.
0 Hz1,0002,0003,000 Hz
12-second example. A clean example made by our own signal generator; signals on the air usually sound noisier.
Field marks16 tones15.625 baudAbout 316 Hz wide
Who uses it?
Amateur radio operators, and the Shortwave Radiogram broadcasts, which send text and pictures.
Where and when can I hear it?
Various ham and shortwave broadcast frequencies.