PACTOR is a radio transmission protocol used by marine and other users, including amateurs,

to send and receive digital information via radio.PACTOR is one of the fastest, most accurate, 

and most efficient ways to send digital data by radio. A robust network of stations that

use PACTOR has been established to relay data by radio to and from the internet, extending

internet access to sea based and other isolated users.



Another Frequency Shift Keying (FSK) transmission mode with typical characteristics as

demonstrated by the two audio files. There are several 'cluster' frequencies in the

19MHz to 24MHz frequency range.