Digital Modes
Digital modes use your computer and radio together to send and receive data, text, and images. From FT8's weak-signal magic to SSTV's image transmission, digital modes have transformed amateur radio.
FT8 - The Most Popular Digital Mode
FT8 (Franke-Taylor design, 8-FSK modulation) has become the dominant digital mode since its release in 2017. It operates using 15-second transmission periods, exchanging call signs, grid squares, and signal reports in a highly structured format.
Why FT8 matters: FT8 can decode signals up to 24 dB below the noise floor. signals that are completely inaudible. This means contacts are possible with very low power (QRP), compromise antennas, or during poor propagation conditions that would make voice or CW impossible.
Getting started with FT8:
- Download WSJT-X (free)
- Connect your radio to your computer (audio cables or digital interface)
- Set your radio to the FT8 frequency for your band (e.g., 14.074 MHz for 20m)
- Set mode to USB and adjust power to 25-50 watts to start
- Configure your call sign and grid square in WSJT-X
- Synchronize your computer clock precisely (FT8 requires accurate time)
- Watch the waterfall and decoded signals appear
See the Frequencies page for FT8 frequencies on each band.
Digital Mode Overview
| Mode | Type | Software | Use Case | Bandwidth |
|---|---|---|---|---|
| FT8 | Weak Signal | WSJT-X | DX, QRP, poor conditions | 50 Hz |
| FT4 | Weak Signal | WSJT-X | Contesting, faster than FT8 | 90 Hz |
| PSK31 | Keyboard Chat | fldigi | Keyboard-to-keyboard QSOs | 31 Hz |
| RTTY | Teleprinter | fldigi, MMTTY | Contesting, ragchewing | 170 Hz |
| JS8Call | Messaging | JS8Call | Real-time text messaging | 50 Hz |
| Olivia | Keyboard Chat | fldigi | Weak signal keyboard chat | Varies |
| SSTV | Image | MMSSTV | Sending/receiving images | ~3 kHz |
| APRS | Position/Data | Various | Position tracking, messaging | Packet |
| Winlink | Winlink Express | Email over radio | Varies | |
| WSPR | Beacon | WSJT-X | Propagation testing | 6 Hz |
| CW | Morse Code | Various | Weak signal, contesting, QRP | ~150 Hz |
APRS
APRS (Automatic Packet Reporting System) combines GPS positioning, weather data, and messaging over amateur radio. Your station's position appears on maps like aprs.fi, and you can send short messages to other APRS users.
In North America, APRS operates on 144.390 MHz. APRS is particularly useful for tracking mobile stations, reporting weather data, and emergency communications.
SSTV - Images Over Radio
Slow Scan Television (SSTV) transmits still images over radio using audio tones. Images take 30 seconds to several minutes to send depending on the mode and resolution.
The most common SSTV activity frequency is 14.230 MHz USB on the 20-meter band. The International Space Station occasionally transmits SSTV images that anyone with an FM receiver on 145.800 MHz can receive.
Software: MMSSTV (free for Windows)
Digital Voice Modes
DMR
Digital Mobile Radio. Widely used digital voice protocol. Works with radios from many manufacturers. Brandmeister is the largest network.
D-STAR
Digital voice protocol by Icom/JARL. Provides call sign routing and internet gateway linking. Primarily used with Icom and Kenwood radios.
System Fusion
Yaesu's digital voice system with WIRES-X internet linking. Compatible with analog FM, so Fusion repeaters work with any FM radio.
Propagation Monitoring
PSKReporter
FreeReal-time map showing where FT8, FT4, WSPR, and other digital mode signals are being received worldwide. The best tool for seeing current propagation conditions.
WSPRnet
FreeWSPR beacon network for testing propagation paths with very low power. Automated beacons map real-time HF propagation worldwide.