CQDeck

Tools · Beta

Morse code decoder

Set your phone by the radio and watch Morse code turn into text.

Uses the microphone. Put your phone or computer within a foot or two of the radio’s speaker.

SignalKey— Hz— WPM— dBStopped
Decoded text appears here.

Two signals at once? Tap or click the one you want on the spectrum.

“Save what it heard” downloads the last minute of audio to this device; nothing is uploaded. If it got something wrong, you can email that file to hello@cqdeck.com with what was really sent, and we’ll use it to improve the decoder. It holds everything the microphone heard, voices included, so listen to it first.

Other ways to listen

A recording from your radio, or W1AW code practice from the ARRL. It stays on this device.

No signal handy? Type a message, pick a speed and some noise, and watch it decode.

How to use it

  1. Set your phone by the radio, within a foot or two of its speaker, with the bottom edge (where the microphone is) toward it.
  2. Press Start listening and allow the microphone. It finds the tone and learns the speed from the first few letters.
  3. Read along. The Signal light stays on while it follows a station. Two at once? Tap the one you want on the spectrum.

For the best results

  • Keep the phone close and the room quiet. Distance and echo cost more letters than anything else.
  • Keep this page open. The screen stays on while it listens; if you switch apps or lock the phone, it may stop hearing.
  • A cable from the radio’s headphone jack to a computer’s audio input beats any microphone: no room noise and no echo.
  • Tune so the Morse is a clear tone around 600 to 800 Hz (a radio’s CW pitch setting, if it has one). Small speakers are weak at low pitches, and the decoder listens from 300 to 1,200 Hz.
  • If your radio has a narrow CW filter, use it: it keeps other stations and noise out.
  • Give it a few letters. It learns each station’s speed, from 5 to about 40 words per minute, and settles in as it goes.
  • Watch the dB reading: 15 or more is comfortable. Under 10, expect mistakes.

What it gets wrong

  • Weak signals close to the noise, and deep fading.
  • Two stations on nearly the same pitch. It follows the stronger one unless you click the other.
  • Uneven hand-sent code, where dits and dahs blur together.
  • A speaker across the room: the echo fills the gaps between letters.
  • Very slow practice with extra-long gaps (5 to 7.5 words per minute) can put spaces in odd places.
  • The first letter or two from a new station, while it learns the speed.

What they’re sending

CQ
Calling any station
DE
From: “this is”
K
Go ahead
5NN
Signal report 599 (N is a short 9)
TU
Thank you
73
Best regards
BK
Back to you
POTA
Parks on the Air
<BT>
A pause between thoughts
<AR>
End of message
<KN>
Go ahead, only the station I’m working
<SK>
End of contact

Your audio stays here

The decoding happens in your browser. Nothing you play is sent to CQDeck or anyone else, and you don’t need an account. More on privacy.

Want to copy Morse by ear? Start with the Morse trainer, and the toolbox has free courses and practice files.