Fldigi - Kambing UI

MFSK
MFSK16 and MFSK8 are multi-frequency shift keyed
(MFSK) modes with low symbol rate. A single carrier of
constant amplitude is stepped (between 16 or 32 tone
frequencies respectively) in a constant phase manner.
As a result, no unwanted sidebands are generated, and
no special amplifier linearity requirements are
necessary. The tones selected are set by the
transmitted (4 or 5 bit) bit pattern and a gray-code table.
The mode has full-time Forward Error Correction, so it is very robust. Tuning
must be very accurate, and the software will not tolerate differences between
transmit and receive frequency. The mode was designed for long path HF DX,
and due to its great sensitivity is one of the best for long distance QSOs and
skeds. MFSK8 has improved sensitivity, but is very difficult to tune, and suffers
more from Doppler. It is useful as the band fades out.
MFSK-32 and MFSK-64 are high baud rate and wide bandwidth modes designed for use on VHF and UHF.
These are very useful for send large documents or files when some transmission errors are can be tolerated.
This is an example of properly tuned MFSK16 signal with a s/n of approximately 9 dB.
The same signal viewed with the waterfall expanded to the x2 factor.
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