FT4 Operation Guide

FT4 protocol

Joe Taylor, K1JT, Steve Franke, K9AN and Bill Somerville, G4WJ

FT4 is an experimental digital mode designed specifically for radio contesting. Like FT8, it uses fixed-length transmissions, structured messages with formats optimized for minimal QSOs, and strong forward error correction. T/R sequences are 6 seconds long, so FT4 is 2.5× faster than FT8 and about the same speed as RTTY for radio contesting. FT4 can work with signals 10 dB weaker than needed for RTTY, while using muchless bandwidth.