QRQ CW Practice using QUiSK SDR, unixCW text file sender, Gstreamer CW Router & RECRI CW Regenerator

[Chuck aa0hw]

QUiSK SDR with the help of unixCW, gSTREAMER & RECRI KEYER allows a unique way to practice your CW copy by EAR

SETUP: unixCW's CW program is sending the same text file at speeds below & just above, say...a current comfortable CW copy by ear speed... pick a text file and speed that is no longer than 10 to 15 minutes or so in length unixCW's CW program is set to operate and send that text file continuously on REPEAT https://unixcw.sourceforge.net/

here is an example of that terminal command: [ each instance of CW is sending at a different speed AND at a different VLF frequency(1khz to 11khz) ]

~/Downloads/unixcw-3.6.0/src/cw$ while true; do (./cw -s alsa -d hw:0,1,1 -f 1John.txt -w 40 -k 47 -t 1000 -v 3); sleep 1; done NOTE: that the alsa loopback virtual audio cable "snd-aloop", is using its 8 sub-channels to route audio from unixCW/cw to a different alsa loopback sub-channel ( 0 to 7)

GSTREAMER ROUTER picks up each sending unixCW VLF signal on each CW's sending subchannel and mixes them all together and sends it to QUISK SDR input alsa loopback cable 0,0

here is the SCRIPT of the GSTREAMER ROUTER: gst-launch-1.0 -v audiomixer name=mix ! queue ! alsasink device=hw:0,1 alsasrc device=hw:0,0,1 ! audioconvert ! audiowsincband mode=band-pass lower-frequency=950 upper-frequency=1050 length=480 window=3 low-latency=true ! audioconvert ! audioamplify amplification=1.31 ! mix. alsasrc device=hw:0,0,2 ! audioconvert ! audiowsincband mode=band-pass lower-frequency=1950 upper-frequency=2050 length=480 window=3 low-latency=true ! audioconvert ! audioamplify amplification=1.31 ! mix. alsasrc device=hw:0,0,3 ! audioconvert ! audiowsincband mode=band-pass lower-frequency=2950 upper-frequency=3050 length=480 window=3 low-latency=true ! audioconvert ! audioamplify amplification=1.31 ! mix. alsasrc device=hw:0,0,4 ! audioconvert ! audiowsincband mode=band-pass lower-frequency=3950 upper-frequency=4050 length=480 window=3 low-latency=true ! audioconvert ! audioamplify amplification=1.31 ! mix. alsasrc device=hw:0,0,5 ! audioconvert ! audiowsincband mode=band-pass lower-frequency=4950 upper-frequency=5050 length=480 window=3 low-latency=true ! audioconvert ! audioamplify amplification=1.31 ! mix. alsasrc device=hw:0,0,6 ! audioconvert ! audiowsincband mode=band-pass lower-frequency=5950 upper-frequency=6050 length=480 window=3 low-latency=true ! audioconvert ! audioamplify amplification=1.31 ! mix. alsasrc device=hw:0,0,7 ! audioconvert ! audiowsincband mode=band-pass lower-frequency=6950 upper-frequency=7050 length=480 window=3 low-latency=true ! audioconvert ! audioamplify amplification=1.31 ! mix. alsasrc device=hw:1,0,0 ! audioconvert ! audiowsincband mode=band-pass lower-frequency=7950 upper-frequency=8050 length=480 window=3 low-latency=true ! audioconvert ! audioamplify amplification=1.31 ! mix. alsasrc device=hw:1,0,1 ! audioconvert ! audiowsincband mode=band-pass lower-frequency=8950 upper-frequency=9050 length=480 window=3 low-latency=true ! audioconvert ! audioamplify amplification=1.31 ! mix. alsasrc device=hw:1,0,2 ! audioconvert ! audiowsincband mode=band-pass lower-frequency=9950 upper-frequency=10050 length=480 window=3 low-latency=true ! audioconvert ! audioamplify amplification=1.31 ! mix. alsasrc device=hw:1,0,3 ! audioconvert ! audiowsincband mode=band-pass lower-frequency=10950 upper-frequency=11050 length=480 window=3 low-latency=true ! audioconvert ! audioamplify amplification=1.31 ! mix

output of SDR also goes to the alsa loopback cable 0,0 From the QUISK SDR .quisk_conf.py config file in the home directory sample_rate =48000 # ADC hardware sample rate in Hertz playback_rate = 48000 # Radio sound play rate name_of_sound_capt = "alsa:plughw:0,0" name_of_sound_play = "alsa:plughw:0,0" another GSTREAMER script picks up the demodulated CW VLF signals on the QUISK SDR ouptput - alsa loopback cable - and sends it to the JACK AUDIO MIXING BAY and then wired over to the CW REGEN MODULE input

YOU CAN choose what PITCH, rise/fall time, raised cosine window, volume by the RECRI SDR MIXER setup(which has a tracking CW BANDPass filter no matter what PITCH) https://github.com/recri/keyer