FT8 (Franke Taylor 8) is an 8 tone MFSK mode, which is optimized for the transmission of numeric codes. It is one of the digital modes in the program package WSJT (Weak Signal communication by K1JT), named after the Nobel Prize laureate Joseph H. Taylor Jr (1993 Nobel Prize in Physics). As the name suggests, the digital modes are designed for making reliable QSOs under extreme weak signal conditions.
|
Parameter |
Value |
|
Frequency range |
HF |
|
Operation modes |
Simplex |
|
Modulation |
8-FSK |
|
Symbol rate |
6.25 Bd |
|
Receiver settings |
USB or LSB |
|
Input format(s) |
AF, IF |
|
Additional Info |
with FEC |
An FT8 cycle starts every 15 seconds, at the 0-th, 15-th, 30-th and 45-th second of a minute. An FT8 signal starts 0.5 seconds into a cycle and lasts 12.64 seconds. It consists of 79 symbols, each 0.16 seconds long. Each symbol is a single steady tone. For any given signal there are eight possible tones. The tone spacing is 6.25 Hz.
Following message types can be decoded:
•CQ {call} {grid}, e.g. CQ CA0LL GG77
•CQ {xy} {call} {grid}, e.g. CQ JA CA0LL GG77
•{call} {call} {report}, e.g. CA0LL OT7ER R-07
•{call} {call} 73/RRR/RR73, e.g. OT7ER CA0LL 73
•Free-text messages (up to 13 characters from a limited alphabet)
•Telemetry data (71 bits as 18 hex symbols)