demo of a DC & Single conversion ULF BAND CW sound card SDR Receiver - @1.3Khz
sdr MODULES from RECRI KEYER https://github.com/recri/keyer
the single conversion setup uses a SIDECHAIN GATE to allow the PEAKS of the ULF 1.3Khz CW received by the tuned RX ferrite rod ULF BAND loopstick antenna to trigger a cw regen system that outputs to a MIXER that adjusts to any CW PITCH you want to receive at...includes a tracking cw audio bandpass filter that follows the mixer frequency adjustments keeps the center of the bandpass filter along with the bandpass width, no matter what frequency the mixer is adjusted to....
ZAMGATE APP https://www.zamaudio.com/
TRIGGER MIDI MONO APP https://lsp-plug.in/?page=manuals§ion=trigger_midi_mono