What Is FT8 and Why Is It So Popular?
FT8 (Franke-Taylor design, 8-FSK modulation) is a digital weak-signal mode developed by Joe Taylor (K1JT) and Steve Franke (K9AN) and introduced in 2017. It uses 15-second transmit/receive cycles and can decode signals as weak as -21 dB below the noise floor — a performance level that no SSB or CW operator can approach by ear.
The result? You can work stations across the globe using just a few watts and a modest antenna, even during poor band conditions. FT8 has become the dominant mode on HF bands worldwide, particularly for DX working and band-opening detection.
What You Need to Get Started
- A licensed amateur radio transceiver with a USB, CAT, or serial interface
- A computer running Windows, macOS, or Linux
- WSJT-X software (free, open-source — download from physics.princeton.edu/pulsar/k1jt/wsjtx.html)
- A sound card interface or built-in USB audio (many modern rigs like the Icom IC-7300 have this built in)
- An accurate PC clock — FT8 timing is critical; use Meinberg NTP or similar
Setting Up WSJT-X
- Install WSJT-X and launch it. Go to File → Settings.
- Under the General tab, enter your callsign and grid locator (e.g., KN22).
- Under the Radio tab, select your rig from the drop-down and configure the CAT port and baud rate.
- Under the Audio tab, select the correct input and output audio devices corresponding to your radio interface.
- Set your transceiver to USB mode and tune to a standard FT8 frequency (e.g., 14.074 MHz for 20m).
- Click Enable Tx and watch the waterfall fill with decoded signals.
Understanding the FT8 Waterfall
The WSJT-X waterfall display shows frequency on the horizontal axis and time on the vertical axis. Each coloured streak is a signal. Decoded callsigns, grid squares, and signal reports appear in the left panel. Double-clicking a decoded line automatically sets up a QSO sequence.
Making Your First FT8 QSO
- Find a clear frequency on the waterfall (no other signals) for your TX frequency.
- Double-click a station calling CQ in the decode list — WSJT-X will set up the exchange automatically.
- Click Enable Tx. WSJT-X will handle the entire QSO sequence: CQ → Grid → Signal Report → 73.
- When the QSO completes, the contact is automatically logged.
Key FT8 Frequencies (USB Dial)
| Band | FT8 Frequency |
|---|---|
| 80m | 3.573 MHz |
| 40m | 7.074 MHz |
| 20m | 14.074 MHz |
| 15m | 21.074 MHz |
| 10m | 28.074 MHz |
Tips for Better FT8 Results
- Keep your TX audio level so the ALC meter barely moves — overdriving causes splatter and poor decoding.
- Use DX Mode in WSJT-X to prioritise DX callers over locals.
- Upload your log to Logbook of The World (LoTW) and QRZ for award credit.
- Monitor PSK Reporter to see who is receiving your signal worldwide in real time.
Beyond FT8: Other WSJT-X Modes
Once comfortable with FT8, explore FT4 (faster, for contesting), JT65 (moonbounce EME), and WSPR (propagation beaconing). All run within the same WSJT-X software package and use similar setups.