The decoding quality starts falling off as the CW speed rises above 30 WPM but it’s still usable. This allows me to use a sidetone of 750Hz and a 150Hz filter on the transceiver. I use the 744Hz tone in the algorithm and a bandwidth of 140Hz. The noise reduction on the TS590-S is needed to allow this, and with NR2=20, fast AGC and reasonably keyed morse it does pretty well. Even so, the decoder has decoded plenty of signals even when drowned in HF mush. As I write, we’re in horrible HF conditions at the moment with poor propagation. I’ve not modified the circuit in any way as I can fiddle with the controls on my TS590-S transceiver to get the decoder to work.

It gets its efficiency by only working for various fixed tones rather than a continuous frequency spectrum as in the FFT. The Goertzel algorithm does much the same as an FFT but in a more efficient way. The CW Decoder circuit and code come from Hjalmar, OZ1JHM and are described in his web page A VERY simpel CW decoder EASY BUILD. Also, those who can not talk for any reason can also use Morse code to express their meaning.Īnd besides all, learning and using Morse code to communicate can be fun and entertaining.I came across a CW Decoder based on an Arduino Uno implementing the Goertzel algorithm, and have lashed together a prototype which works quite well. Many ships use Morse code to send light for communication or help. Morse code is also used in aeronautical navigation systems.

Morse code is still popular among enthusiasts in the field of amateur radios. –.-.-Īlthough Morse code is not used as much as the past anymore, it still has its own applications. Try to write your name in Morse code for practice.Įlectropeak =.

Imagine the dot as a unit of time, then the dash is three units of time, the distance between the parts of a letter is a unit of time, the distance between two consecutive letters is three units of time, and the distance between the words is seven units of time.įor instance the word SOS, the worldwide standard for requesting help is … - … in Morse code. Morse code can be transmitted in different ways: originally as electrical pulses along a telegraph wire, but also as an audio tone, a radio signal, light, body language, frequency and more.

Arduino cw decoder fft