just another example of using REAPER DAW to take 555 square wave output , convert it to shaped sine wave

[Chuck Vaughn]

https://youtu.be/bnvhUi-NTp0?si=QfBBb3cJ5_Dqg52W

using native plugins in REAPER DAW, to create a CW Regeneration "RE-KEYER"...- takes a harsh/raspy square wave input from a 555 keyed CPO output, over to the MIC INPUT(green wave on scope) and converts it into a shaped sinewave CW note output, with raised cosine edges, using 3 reaper plugins: Tone Generator, ReaGate, and the Apple 12 Pole Filter REAGATE is operating in sidechain mode, holding back a pure sine wave at your desired CW PITCH, until REAPER's sidechain is 'keyed' by the 555 square wave keyed CPO's output Reaper puts a 5 ms rise/fall time onto its trapezoid shaped output, and gets shaped further into raised cosine edges by the APPLE 12 bandpass audio FILTER https://www.reaper.fm/download.php

[df7t...@gmail.com]

Hi Chuck,

seeing (upper picture) and listening the nice output signal, I had to look into the output of sineCW30 (lower picture with rise/fall = 5ms, pitch 700 Hz, 40 wpm,  exponential envelope).

Not surprising -- the DITs look very similar. Your one perhaps being a bit more "rounded" and thus a bit more pleasing sound.

I assume the horizontal scale in your video's scope is at 5 ms / division.

73

Tom

[Chuck Vaughn]

You bring up a fascinating point...

there is so much diversity and preference when comparing

CW ELEMENT edges...

each OP would have their preferred 'type'

exponential, linear, et al.   etc....

not to mention the many raised cosine windows besides HANN and BLACKMAN

to choose from.... especially at QRQqCW speeds... where

each window, type of edge, comes into play more significantly...

https://en.wikipedia.org/wiki/Window_function

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[Chuck Vaughn]

just testing diy FERRITE RODs made from ferrite slugs to act as a passive L/C CW audio bandpass filter to filter out harsh raspy square wave CPO:

https://youtu.be/b08z-PCeHsY?si=SCuuvvMf7wYbGrjN

On Fri, Mar 8, 2024 at 4:17 PM df7t...@gmail.com <df7t...@gmail.com> wrote:

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[aa0hw]

Here is a new method i found that uses a software VOLTAGE CONTROLLED AMPLIFIER  (ams-vca plugin)...

it takes less than 1 ms to process a harsh square wave CW NOTE and convert it into a beautiful Pure Sine Wave raised cosine edged CW NOTE...

and you can adjust it to be LIGHTER/heavier in its sound...also adjust the pitch & volume  etc..

https://youtu.be/snIFxl77alk 

[df7t...@gmail.com]

Hello Chuck,

nice solution with the AMS VCA amp!

What a coincidence! -- simultaneously we both are working on "milli seconds" :)

You for the conversion time - me for the consistency of the lengths of DITs and DAHs at sineCW60's output.

GL 73

Tom

[df7t...@gmail.com]

Hi again Chuck,

I could not resist to measure the the delay of the start of a DIT at the input of sineCW60 to the start of the DIT at its output.

KEYED TIME SETTING is "NOT DELAYED", Pitch is 1300 Hz, sample rate has been 44.1 kHz. The square wave at the input is at about 4 kHz.

Sound card is the Behringer UCA222 (which I once bought according to your recommendation -- a great, great card for this kind of experiments)

The upper recording is the left channel at the input (square wave), the lower recording is the right channel (sine)

of the output.

The delay is about 20 samples, or 20/44100 seconds = about 500 us :)

Recording has been done with the module "WaveRecorder", a module of SynthEdit, which temporarily had been added

to the sineCW60 structure (circuit).

73

Tom DF7TV

[Chuck Vaughn]

half a millisecond !

that's some serious  "QRQ"   super speed travel     from start to finish...

  ULTRA LOW LATENCY OPERATIONs

congrats !

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[df7t...@gmail.com]

Thanks Chuck!

The, perhaps more realistically 600 us, delay is directly related to the delay line and monostable (200 + 400 us) at the input of sineCW60 to detect the keyed time of the square wave.

So - the sound card and processing by the rest of the structure/program seem to contribute near zero additional latency.

(BTW: One might reduce the delay further by omitting monostables at the input and using three different delay lines instead. For a FIXED square wave frequency of 20 kHz -- it should be possible to get down

to 100 us. But I prefer to "allow" a range of frequencies for the square wave, >= 4 kHz at present,  and this kind of setup proved to work nicely with sineCW30/60)

73

Tom