FT8 transformed HF operating after 2017. It encodes a fixed-format exchange into 15-second transmissions that decode reliably at around −21 dB signal-to-noise — well below what the ear can hear.
How a contact works
Everything is automated by WSJT-X once you double-click a callsign. The exchange is:
CQ KX4XYZ EM75KX4XYZ W1ABC FN42W1ABC KX4XYZ −13KX4XYZ W1ABC R−09W1ABC KX4XYZ RR73KX4XYZ W1ABC 73
Roughly a minute, and that is the entire contact — grid square and signal report, nothing else.
Why it matters
- Works when the band sounds dead.
- Works with 5–25 watts and a compromise antenna, which makes HF practical from an apartment.
- Reports to PSK Reporter, giving you a live map of where your signal is actually landing — the
best antenna diagnostic in the hobby.
Practicalities
- Standard dial frequencies: 7.074, 10.136, 14.074, 18.100, 21.074, 24.915, 28.074 MHz USB.
- Your computer clock must be within about a second of UTC. Run NTP.
- Keep power low and ALC at zero; FT8 is a 100% duty-cycle mode and will cook a transmitter run at
full output.
Relatives
WSPR beacons at milliwatt levels to map propagation. MSK144 works meteor scatter on 6 m and 2 m. JS8Call builds free-form keyboard messaging and store-and-forward on top of the FT8 waveform — useful for emergency communication.
The debate
Some operators argue FT8 is not really conversation. It is not — but it keeps people on the air through solar minima and from restricted antenna sites, and it has brought a large number of newcomers to HF.