[nrv-hams] Sine Wave Morse Code Oscillator Circuit Needed

[Cam Coble]

I am using an RC low-pass filter with 4 stages at this point already to try
to smooth a square wave. It's just not looking good on the scope.
Values are 1.5k resistors in series with caps of 0.01 uF to ground.

--
Cam, W4XXV

On Thu, Jul 11, 2024 at 8:45 AM Alvin P. Schmitt <schmitt.alvin at gmail.com>
wrote:

>
> https://www.google.com/search?q=how+do+you+get+a+sine+wave+from+a+square+wave+circuit&sca_esv=554492d1fd62c51c&sxsrf=ADLYWIJqd2SaJGzaOZrPEQi32KDfCfsTqA%3A1720701822058&source=hp&ei=ftOPZo_FAZmu5NoPwbW6uAc&iflsig=AL9hbdgAAAAAZo_hjjYx0hYsYOqP7lCWqGu9tj_czDU0&ved=0ahUKEwiP_PbmgZ-HAxUZF1kFHcGaDncQ4dUDCBc&uact=5&oq=how+do+you+get+a+sine+wave+from+a+square+wave+circuit&gs_lp=Egdnd3Mtd2l6IjVob3cgZG8geW91IGdldCBhIHNpbmUgd2F2ZSBmcm9tIGEgc3F1YXJlIHdhdmUgY2lyY3VpdDIFECEYoAEyBRAhGKABMgUQIRigATIFECEYoAEyBRAhGKABMgUQIRirAkiSBlAAWABwAHgAkAEAmAFkoAFkqgEDMC4xuAEDyAEA-AEC-AEBmAIBoAJrmAMAkgcDMC4xoAfWCA&sclient=gws-wiz
>
> On Thu, Jul 11, 2024 at 8:25 AM Cam Coble <cam at doubleclickdata.com> wrote:
> >
> > Not as easy as I thought...
> >
> > OK, there are *plenty* of circuits out there making use of 555 timers and
> > other methods that create square waves, and I can certainly filter the
> > output to make it sound a little better, but I'm reaching out to find if
> > anyone has a link or schematic for a nice sine wave oscillator for CW
> > practice.
> >
> > If there is a good kit, send that link too, but I prefer to scratch
> build.
> > This may be something we use for a Winter Build Project if I get the
> time.
> >
> > My last attempt was using a side-tone generator from the W1FB's QRP
> > Notebook (pp145 lower left circuit) along with an LC filter. I evidently
> > need practice with my filters as It looks like I only got the start of
> the
> > square wave smoothed out. This helps, but there's nothing like the sound
> of
> > a real sine wave.
> >
> > Target is 700 Hz (or variable), and at least headphone output levels.
> > Bonus for some debouncing for use with a Bug.
> >
> > Help!!!
> >
> > 73
> > --
> > Cam, W4XXV
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