The AD5DZ MODULAR SDR software - demo of the AD5DZ SDR modules used to receive a VLF band QRQ CW signal

[Chuck aa0hw]

using all AD5DZ SDR software MODULES to capture & demodulate a QRQ CW signal heard on the VLF BAND at 10101 Hz...this video also shows one special adjustment made to a RECRI KEYER FILTER file setting to create a custom CW AUDIO BANDPASS FILTER for QRQ CW RX copy

a VLF RX ANTENNA - tuned bi-coil ferrite rod - brings in the VLF SIGNAL picked up. to the sound card's MIC INPUT jack...then
the AD5DZ LO-MIXER module is used to dial in the VLF FREQ and the CW PITCH, connecting to the next AD5DZ SDR MODULE, is the AD5DZ FILTER - which has already been re-set in the "keyer" file to provide a cw bandpass from 500hz to 1000hz, then the next AD5DZ SDR MODULE is a GAIN MODULE to increase the volume to suit your preference (-6db output in this example)
ALSO the AD5DZ has 2 SPECTRUM ANALYZER modules, one at the MIC INPUT and the other one after the FILTER and GAIN Module to show the spectrum of the final RECEIVED cw note at about 750 hz...also is another AD5DZ SDR MODULE - a SCOPE that shows the final CW 750 hz waveshape (after the bandpass filter and gain modules) and also a special AD5DZ VU METER module

https://github.com/recri/keyer

here are the commands used to bring up all the AD5DZ SDR MODULES - to be able to receive a VLF CW signal at 10101 Hz

~/keyer/bin$ ./keyer -start lo-mixer@tuneRX
~/keyer/bin$ ./keyer filt
~/keyer/bin$ ./keyer gain
~/keyer/bin$ ./keyer xmet
~/keyer/bin$ ./keyer xspe
~/keyer/bin$ ./keyer xspe

HERE IS the first video which explains a little bit more about the AD5DZ SDR MODULES: