Decodium

This is a community package of Decodium, maintained independently and unaffiliated with the Decodium project. It repackages the official upstream AppImage unmodified and follows upstream releases automatically.

Decodium is a weak-signal digital modes program for amateur radio operators, in the WSJT-X family, with its own FT2 mode and a reworked interface.

• FT8, FT4 and FT2; Q65, MSK144, JT65, JT9, JT4, FST4 and FST4W; WSPR.
• Native analogue SSTV, receive and transmit.
• Manual QSOs, Auto Sequence, Auto CQ and Multi Answer Mode.
• Rig control through Hamlib, including split operation and PTT.
• RTL-SDR receivers as an audio source.

Permissions: this package grants audio (your radio's sound interface through the host sound server), network access (PSK Reporter, callsign lookups and the UDP messages logging programs listen for), and device access. Device access is granted by default because rig control needs it: Hamlib drives the radio's CAT and PTT over USB serial ports and RTL-SDR dongles are raw USB devices, and Flatpak has no narrower permission for either. Without it Decodium can decode but cannot key a transmitter. To run receive-only without it: flatpak override --user --nodevice=all io.github.iu8lmc.Decodium. Settings, logs and captures stay inside the sandbox.

FT8 and its relatives need an accurate clock; keep the host's time synchronised, as you would for any installation.