this is a follow up video to this one:
https://youtu.be/JPecQqQk85Q
the K1EL K40 CW KEYER's SPEAKER AUDIO OUTPUT is hooked directly to the Ferrite Bobbin Core Inductor Coil input...an EMF PICKUP COIL is right on top of the COIL(cheap telephone recording emf pickup coil)...connect the EMF PICKUP coil to one channel of the PC's MIC INPUT or LINE INPUT...use a simple Gstreamer coded CW AUDIO BANDPASS FILTER to get rid of the CW Keyer Speaker's raspy harmonics and also place a raised cosine like edge on the rise and fall time(@ 6ms), transforming the raspy tone into a very pleasant CW TONE
in this QRQ CW example of this setup...the tone was raised from 680 hz to 800 hz and the Gstreamer pipeline adjusted accordingly:
****************************************************************
gst-launch-1.0 jackaudiosrc ! queue ! "audio/x-raw,channels=1,rate=48000,format=F32LE" ! audiowsincband mode=band-pass lower-frequency=700 upper-frequency=900 length=700 window=hamming ! audiorate ! queue ! jackaudiosink buffer-time=10000
***************************************************************
the Gstreamer CW AUDIO BANDPASS FILTER code...does a great job of filtering out virtually all of the harsh square wave harmonics and also produces an output CW note that has a symmetrical RISE & FALL time @ 6ms - All in all..i thought it sounded pretty good all the way from 60 wpm - to 120 wpm
Views: 23
Tags:
© 2024 Created by Chuck aa0hw. Powered by
You need to be a member of QRQcw to add comments!
Join QRQcw