Re: Random thoughts on sinewave oscillators

"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:vf5dkk$tubm$1@dont-email.me...

On 20/10/2024 4:52 pm, Edward Rawde wrote:

"Edward Rawde" <invalid@invalid.invalid> wrote in message news:vf2569$2f0q$1@nnrp.usenet.blueworldhosting.com...

"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:vf20si$96u8$1@dont-email.me...

On 20/10/2024 3:36 am, Edward Rawde wrote:

"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:vevqip$3q3dn$1@dont-email.me...

On 19/10/2024 2:03 pm, Edward Rawde wrote:

"john larkin" <JL@gct.com> wrote in message news:j656hjp1rq659uh61k3q75bipaf386qqh1@4ax.com...

On Fri, 18 Oct 2024 18:58:43 -0400, "Edward Rawde"
<invalid@invalid.invalid> wrote:
>

"Jeroen Belleman" <jeroen@nospam.please> wrote in message news:veumn5$3fbqu$1@dont-email.me...

On 10/18/24 23:19, Edward Rawde wrote:

"Cursitor Doom" <cd999666@notformail.com> wrote in message news:veuirv$3cmo3$10@dont-email.me...

On Fri, 18 Oct 2024 15:59:09 -0400, Edward Rawde wrote:
>

"Cursitor Doom" <cd999666@notformail.com> wrote in message
news:veucs2$3cmo3$9@dont-email.me...

On Fri, 18 Oct 2024 14:20:48 -0400, Edward Rawde wrote:
>

"Cursitor Doom" <cd999666@notformail.com> wrote in message
news:veu7kt$3cmo3$8@dont-email.me...

On Fri, 18 Oct 2024 13:47:02 -0400, Edward Rawde wrote:
>

"Cursitor Doom" <cd999666@notformail.com> wrote in message
news:veu45s$3cmo3$5@dont-email.me...

On Fri, 18 Oct 2024 11:25:19 -0400, Edward Rawde wrote:
>

"piglet" <erichpwagner@hotmail.com> wrote in message
news:vetde5$38sbk$1@dont-email.me...

Edward Rawde <invalid@invalid.invalid> wrote:

>
<snip>
>
This will probably mess up the thread structure, but here's another variation. It struck me that the current spike being pulled
from the amp through D1 is probably messing up the op amp's output stage, so I decided to buffer the op amp output with a PNP to
minimise this.
>
The 4th harmonic is now almost 50dB below the fundamental.

If the problem is asymmetry in the drive from the amplifier then why not symmetricalize it like this.

An FFT from 6s to 20s shows reasonably clean performance at 1kHz and a simple filter should be able to get more than 50dB down at
other harmonics.

R9 at 100 ohms is even better.

Manual adjustment of R5 will be needed in any real circuit.

I'd probably make R10 10 ohm variable, R9 1k variable and R5 100k variable and then use the extremely scientific process of
adjusting all three for best performance.

I may not be able to reply further for a few days after today.

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TEXT -184 472 Left 2 !.tran 0 20s 0s startup