CW SIDETONE CLEANER - polish up and take the harshness out of that Sidetone with Zamgate & BP Filter

[Chuck aa0hw]

zamgate is a used as a 'GATE', to help balance and equalize the RISE/FALL time of the original CW NOTE passing through it

https://www.zamaudio.com/

a BANDPASS FILTER, finishes the job by cleaning up and reducing the unwanted/unpleasant Morse Code audio Tone's harmonics and CW edge noise

https://calf-studio-gear.org/

[Chuck aa0hw]

CW FILTER for the vintage HEATHKIT CODE PRACTICE OSCILLATOR using the same zamgate/filter setup

[Chuck aa0hw]

Here is just the FILTER cleaning up a harsh 555 timer CPO square wave and by itself converting it to a pure sine wave note with raised cosine edges

bandpass filter from: https://github.com/recri/keyer

after compiling RECRI KEYER

cd keyer

cd bin ./keyer filt -grid 1

will bring up the BANDPASS FILTER module that you adjust its settings to your preference

[Chuck aa0hw]

QRQ CW over SONOBUS using a 555 timer CPO - convert to a pure sine wave shaped note with this filter

BandPass filter from RECRI KEYER

https://github.com/recri/keyer

SonoBus

https://github.com/recri/keyer