STANAG 4481 FSK defines the technical standards for some NATO Naval HF shore-to-ship FSK (Frequency Shift Keying) transmissions.
This signal is most often seen with an FSK shift of 850 Hz and a 75 bps data rate. However single channel data rates of up to 600 bps are possible, and multichannel rates of up to 1200 bps are possible. Data rate changes are seen in 75 Hz increments.
The specification does identify KG-84 as the encryption method, and the signal is most frequently seen with KG-84 frames. However the data can be sent unencrypted ("in the clear").
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