tools / cw decoder

CW Decoder

Real-time Morse decoder. Feed audio from your radio or microphone — the Goertzel filter isolates the CW tone and decodes it live.

reference chart

input

Picks up CW from your radio speaker. Auto-gain adjusts for distance.

tuning

Hz
Signal
0%

Noise gate — ignores signal below this level. Raise to cut background noise.

200 Hz

Filter bandwidth around the target tone. Narrow to reject nearby signals on a crowded band.

timing

10
20
Live WPM
—

gap sensitivity

2.5
5.5

Lower = splits letters sooner. Raise if letters are splitting incorrectly. Standard Morse: letter 3, word 7.

V1.7

tone
cw decode
 

spectrum

waterfall

400 500 600 700 800 900

decoded output