Re: CW Modem #modem

K3eui <K3eui@...>

Interesting conversation about different ways of perceiving CW.
I hear some of the worst "fists" ever these days on 40m, with the dah's maybe 5 times as long as a "dit" short sound. FLDIGI goes nuts trying to create print from most hand-key sent CW.  Kind of a CW slang, of sorts.

When I was a teenager (60 yr ago) I had no trouble copying anyone sending 20-30 wpm with those Vibroplex semi-automatic bugs, or even a straight key. But in my older years (now 75) I find the thrill of copying poorly sent CW not as rewarding, and straining now.

I wonder, had FT8 or PSK31 been "invented" before CW (on/off keying of a carrier) would be so obsessed with this mode called CW? PSK and FT8 take up less spectrum than CW, and create fewer fewer problems.

With CW, the brain has distinguish a tone, or no signal, but the darn "noise" is in our way. There is never silence, especially on noisy HF bands these days.  My mind can not (virtually) eliminate the noise the way it used to when I was younger.  In fact, the lower pitch CW tone around 600 Hz is harder now for me to understand than a higher pitch tone of around 1000 Hz.  Why is that?

I find myself operating CW more now with my (Icom) rig in USB-D mode, and tune in CW to 1000 Hz  to  1500 Hz on the FLDIGI waterfall. 
That sound can be separated from the background "noise" more easily now. I like to run a 500 Hz bw but center it at 1500 Hz.

I'm not sure why I do this, but it is less tiring for my brain than listening to CW at 600 Hz pitch.
I'm a former bassoon player, so I did enjoy those bass sounds.

Barry  k3eui

On Dec 6, 2020, at 4:25 PM, Artie Langston <artielangston@...> wrote:

I think the challenge is not actually in signal processing, but in some sort of artificial intelligence. Fldigi reads extremely well considering, when it's another machine doing the sending. With the peculiarities of various humans, on various keys, not so much.

This leaves the question, is designing an AI of that sophistication going to be worth the time and investment required?

I have noticed that my Digital Audio Workstation I use in my work as a musician can do amazing things with what is referred to as Quantizing a musical performance to various degrees. It can take a rhythmically  imprecise musical performance and then "line it up" correctly with the beats and time signature, so it sounds pretty perfect.

Perhaps once the WPM is detected by the software, it could then quantize the CW before decoding, thus delivering something like W1AW or keyboard generated copy even from a shaky fist.



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