What Is FT8?

FT8 (Franke-Taylor design, 8-FSK modulation) is a digital weak-signal communication mode developed by Joe Taylor (K1JT) and Steve Franke (K9AN) and released in 2017. In just a few years, it became the most widely used amateur radio mode on HF bands worldwide. The reason is simple: FT8 can decode signals that are completely inaudible to the human ear, enabling contacts under marginal propagation conditions that would be impossible with voice or even CW.

How FT8 Works

FT8 operates on a strict 15-second transmission cycle. Each transmission is exactly 12.64 seconds long, with a short gap before the next cycle begins. A complete contact — call, response, signal report exchange, and confirmation — takes about 90 seconds through a structured sequence of short messages.

Your computer's sound card (or a built-in USB audio interface) connects to your transceiver, passing audio tones to the radio for transmission and receiving audio for decoding. The software does the heavy lifting of encoding and decoding the signals.

What You Need to Get Started

Hardware

  • HF transceiver — Any all-mode HF radio capable of SSB operation (the mode FT8 is transmitted on)
  • Computer interface — Either a dedicated USB sound card interface (Signalink USB, MASTERS Communications DRA series, or similar) or a radio with a built-in USB audio/CAT port (many modern radios like the Icom IC-7300 have this built in)
  • Computer — Windows, macOS, or Linux; FT8 is not CPU-intensive

Software

  • WSJT-X — The free, open-source program developed by the mode's creators. This is the standard application for FT8, FT4, WSPR, and other weak-signal modes. Download from physics.princeton.edu/pulsar/k1jt/wsjtx.html
  • GridTracker — Optional companion app that displays your contacts on a map in real time
  • JTAlert — Optional Windows app for logging automation and alerts for new DX/grid squares

Time Synchronization Is Critical

Because FT8 uses strict 15-second cycles, your computer clock must be accurate to within roughly ±1 second. Use an NTP client or a program like Meinberg NTP (Windows) or simply enable automatic time sync in your OS settings. If your clock is off, you won't decode signals or make contacts.

Setting Up WSJT-X

  1. Install WSJT-X and open Settings
  2. Enter your callsign and grid square (6-digit Maidenhead locator)
  3. Configure the audio input/output to match your interface device
  4. Set up CAT control if your radio supports it (enables automatic frequency and PTT control)
  5. Select FT8 mode and choose an active band (20m is typically the most active)
  6. Click Enable Tx and watch calls decode on the waterfall

Making Your First Contact

When you see a station calling CQ in the decode window, double-click their call to begin an automated contact sequence. WSJT-X handles the message formatting automatically — you'll see the exchange unfold in the log window. A typical contact looks like this:

  • CQ W1ABC FN42 — Station calling CQ with their grid square
  • W1ABC K9XYZ EN52 — Your response with your grid square
  • K9XYZ W1ABC -12 — Their signal report to you (in dB)
  • W1ABC K9XYZ R-08 — Your report back (R = received)
  • K9XYZ W1ABC RRR — Acknowledgment
  • W1ABC K9XYZ 73 — Sign off

FT8 vs. Other Digital Modes

Mode Speed Weak Signal? Best Use
FT8 ~1 min/QSO Excellent DX, band conditions testing
FT4 ~30 sec/QSO Very good Contesting
WSPR No QSOs (beacon) Outstanding Propagation research
JS8Call Slow, flexible Good Conversational messaging
PSK31 Moderate Moderate Keyboard-to-keyboard chat

Is FT8 "Real" Ham Radio?

This debate is common in amateur radio communities. FT8 contacts are brief, structured, and largely automated — a far cry from a casual rag-chew on 40m. But FT8 genuinely expands what's possible: working over 100 countries with a modest antenna, or making contacts when propagation would otherwise shut you down. It's a tool — and a remarkably powerful one. Use it alongside voice and CW, and you'll be a more capable operator overall.