Digital modes turn a transceiver and a computer (or a sound-card interface, or nothing but the radio in the case of DMR) into a data link. They fall into three broad families:
- Weak-signal modes — FT8, JT65, WSPR, MSK144. Extremely
- Keyboard and messaging modes — PSK31, RTTY, Olivia. Real conversation, typed.
- Networked and packet modes — Winlink, APRS, AX.25
- Digital voice — DMR, D-STAR and Fusion.
narrow, extremely tolerant of noise, rigidly structured exchanges.
packet, mesh. Moving files, email and telemetry.
What you need
Most HF digital work needs an interface that connects the radio's audio and PTT to a computer; modern transceivers have a USB sound card built in. The software (WSJT-X, fldigi, JS8Call) is free and cross-platform.
Settings that matter
- Drive the radio gently. ALC should barely move; overdriving a digital signal splatters across
- Keep your clock accurate. Weak-signal modes are time-synchronised to the second; use NTP.
- Use the conventional frequencies for each mode and band, or nobody will hear you.
the band and is the single most common newcomer mistake.