FT8 sends a fixed 77-bit message in a 15-second slot and can be decoded far below the noise floor, well past the point where a human could hear anything at all. That sensitivity is why it took over: it works on dead bands, with modest antennas and low power.
The exchange is minimal and largely automated — callsign, grid square, signal report, acknowledgement. Some operators love that it removes the barrier of language and marginal conditions; others feel it removes the conversation. Both views are widely held and neither is going away.
Your computer clock must be accurate to about a second or nobody will decode you. This is the single most common reason a new FT8 station hears everyone and works nobody.
At a Glance
- Category
- Digital data
- On the air since
- 2017
- Bandwidth
- About 50 Hz
- Speed
- 15-second transmit/receive sequences
- What you need
- A sound card interface such as a SignaLink or Digirig, or a radio with built-in USB audio
- Where to listen
- 7.074, 14.074, 21.074 and 28.074 MHz among others — see the band plans
Dial Frequencies, Band by Band
Set your radio to the dial frequency in upper sideband and let the software find the signals inside the audio passband. These are the frequencies operators have settled on, not legal band edges: those are on Band Plans.
| Band | Dial frequency (MHz) |
|---|---|
| 160m | 1.840 |
| 80m | 3.573 |
| 40m | 7.074 |
| 30m | 10.136 |
| 20m | 14.074 |
| 17m | 18.100 |
| 15m | 21.074 |
| 12m | 24.915 |
| 10m | 28.074 |
| 6m | 50.313 |
| 2m | 144.174 |
Related Reading
Digital · Operating · Getting started
The digital mode that fills the HF bands. What it is, what you need, and how a contact actually goes.