Questions, answered.

A way to get the radio’s own audio into the phone or computer. The best is a USB audio interface or sound-card adapter between the radio’s headphone, line or data output and the phone or computer. A TRRS cable into a phone’s headset socket works too, and so does a radio with its own USB audio. How to connect your radio has diagrams for each.

It works for a quick try, but copy is much weaker than over a cable or USB interface. The room adds noise and echo, and the phone’s own audio processing works against weak signals. Dahdio is built for a direct connection, and that is where it does its best work.

Bluetooth is a narrowband voice link, and many headsets add noise suppression. Strong signals decode almost as well as over a cable; weak ones noticeably worse. For weak-signal work use a cable or USB.

Dahdio chooses its input when you press Listen. Press Stop, then Listen, and it will pick up the USB interface. The status line shows which input it is using, for example “Listening · USB audio”. You can also choose an input in Settings › Input.

That is usually a ground loop, especially with the phone or computer on a charger. An audio isolation transformer in the audio lead breaks it, and running on battery helps. See Hum and ground loops.

It finds every CW signal in the audio and decodes them all at once. You read one full screen; the others are on the tuning strip and the “+N stations” list. During early access there is no limit. The free tier decodes up to 4 at once; Dahdio Full has no limit.

Dimmed text may still change. The decoder can revise the last few characters as more of the signal arrives; once it is sure, the text turns solid.

Dahdio stays quiet when what it hears doesn’t look like copy, so noise and carriers don’t fill the screen. If a weak station is being held back, the Show everything switch in Settings shows all of it. Check the input level too: see Setting the level.

It helps with common amateur-radio words and abbreviations. You choose how much it may influence the decode in Settings › Language assist, from off upwards. More assist reads plain English better and can talk itself into words that were not sent.

No. Decoding happens entirely on your phone or computer.

Not in this version. On Android, what you send plays as a sidetone at your chosen speed, pitch and volume; the Linux version keeps the timing but has no sidetone yet. Keying a radio directly is planned.

In the logger, Enter sends the next message of the QSO and logs it at TU, the way contest loggers do.

ADIF (with per-park files for POTA), SOTA CSV and Cabrillo. Your log stays on your device until you export it.

While Dahdio is in early access, everything is unlocked, with no limits. When early access ends, there will be a free tier (up to 4 stations at once, 10 minutes a session and 30 minutes a day) and Dahdio Full, which removes the limits.

Dahdio Full is sold through Google Play as a monthly or yearly subscription, or as a 1-month or 12-month pass that never auto-renews. Subscriptions are managed and cancelled in Google Play, and Google Play handles refunds.

Android and Linux. iOS, macOS and Windows will come later.

No. Audio is decoded in memory as it arrives, and never recorded or sent. There is no account and no analytics. The privacy policy has the details.

Ham and More, the makers of HaM. The name is dah, the long element of Morse, and radio.