passive QRQ CW AUDIO BANDPass filter using 3 series/parallel tuned Ferrite Rod Loopstick Antenna stages

[Chuck aa0hw]

SQUARE WAVE to SINE WAVE by a 3 stage CW AUDIO BANDPASS FILTER setup using 3 sets of tuned ferrite rods,  tuned similar in the way that an antique crystal wireless set would be tuned at the antenna stage, the passive bandpass filter middle stage, and the 3rd filter going to the 1st stage of detection...

GO FROM THIS:

TO THIS:

the QRQ CW pitch was set to be about 528hz as the target cw pitch

a picture of the 3 sets of tuned ferrite rods CW AUDIO bandpass stages

Here is a video demo of the QRS version of this test...

and here is the follow up QRQ CW test using the same filtering setup:

see video description notes in the first video for more info on the setup