VerityRF Modem

VerityRF Modem is an open-source sound-card modem for amateur radio. It uses the VARA HF and VARA FM protocols on the air and offers the same TCP host interface as VARA, so PAT, VarAC and other VARA clients can use it in place of VARA.

It is written in Rust and runs on Linux (x86_64, arm64 and 32-bit ARM, including the Raspberry Pi) and Windows. It is pre-release software: version 0.1.0.

What it includes

• verityrf, the modem. It runs without a screen and needs one sound card. VARA HF at 500, 2300 and 2750 Hz, or VARA FM narrow and wide. Command port 8300, data port 8301, and an optional KISS port (8100) for broadcasts.
• The desktop app. It starts and stops the modem and shows the link: S/N, speed level, data, spectrum and waterfall, and an activity log. All settings can be edited in it.
• verityrf-observer. It decodes VARA HF sessions between other stations, from a sound card or a recording, and prints what they send. It can also serve a web page with --http.

The full list is on Features.

Clients

Point the client at 127.0.0.1, port 8300, as you would for VARA. We have used it with:

• PAT (Winlink), with its varahf and varafm transports;
• VarAC, for chat, CQ, beacons and broadcasts, on VARA HF and VARA FM.

Other programs that use VARA's command, data or KISS ports should work the same way.

Status

We have tested VerityRF Modem against VARA HF 4.9.0 and VARA FM 4.4.0 on simulated radio channels, with paired runs and byte-for-byte checks of the data delivered. Compatibility has the results and the list of what is still untested.

The source code is on GitHub. Releases will be published there; see Downloads.