Morse Decoder Tools
Edit on GitHubDecode the beacon payload with software, SDR plugins, or a plain phone app
Morse Decoder Tools
Overview
You do not need to read Morse by ear to receive a payload. Several free tools decode the keying automatically - useful for verifying payloads on the bench and for confirming a real transmission contains the expected name and coordinates.
Decoding Methods
| Method | Tool | Best for |
|---|---|---|
| SDR audio decode | SDR# plugin “CW decoder” or “Digital Voice” | Live waterfall decode |
| Phone app | Morse decoder apps (record and decode) | Field checks |
| Desktop decoder | fldigi, CWGet, MultiMorse | Precise timing analysis |
| Online | Web Morse decoders (paste audio file) | Occasional use |
| By eye on waterfall | See the blips yourself | Instant verification |
The fldigi Path
fldigi is a free ham-radio digital mode program with a solid CW decoder:
- Connect the SDR audio (or a phone recording) to the PC input.
- Open fldigi, select CW mode.
- Set the center frequency so the tone sits near 1000 Hz.
- Start the decoder and watch text appear.
Decoding With a Phone
- Record the beacon audio with the phone’s recorder.
- Open any Morse decoder app and load the recording.
- Adjust the WPM setting to match the beacon (13 WPM default).
- Read the decoded text.
Timing Reality Check
The firmware uses PARIS-standard timing with unit duration 1200 / WPM ms. At 13 WPM a dot is 92 ms. Decoders configured for the wrong WPM still decode but produce characters slowly; set 13 WPM for the default configuration.
What the Payload Should Look Like
| Configuration | Decoded text |
|---|---|
| Base only | SOS |
| Name only | SOS DE MARIO ROSSI |
| GPS only | SOS PSN N4553 E01230 |
| Full | SOS DE MARIO ROSSI PSN N4553 E01230 |
See GPS Integration for the coordinate format.