Re: Random thoughts on sinewave oscillators

On a sunny day (Wed, 16 Oct 2024 16:55:24 -0400) it happened "Edward Rawde"
<invalid@invalid.invalid> wrote in
<vep97r$2cpo$1@nnrp.usenet.blueworldhosting.com>:

Is the reason why this doesn't produce a better looking sinewave because the amplifier slew rate is faster going down than it is
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going up or some other reason?
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Ignore the wild decoupling, it took me long enough to get the concept to work at all.
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I'm aware that a single package containing two op amps could probably do a much better job.
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Open the file in notepad++ (which you do use don't you?) and under encoding select Convert to ANSI. Save the file.
That will fix issues with u symbols.

Cannot use your funny numbers
but as you ask for oscillators and thoughts about those, here some of mine
Long ago in the early IBM PC days, (19 eighties?) I needed some audio sweep sine generator
programmed a sine wave table in an EPROM, 8 bits, added a DAC chip
used a 4046 as variable oscillator, added a 4040 binary counter, used  that to drive the EPROM. resulted in a nice audio range sweep.
Of course with a decent sound card and Linux these days use 'sox' for the audio range to generate tones and sweeps etc:
 https://www.audiosciencereview.com/forum/index.php?threads/howto-sox-audio-tool-as-a-signal-generator.4242/
I use sox in Linux on a Raspberry Pi... to make nice test tones.
Good sound card helps.
Sine tables you can of course use in a micro, using that in a Microchip PIC micro here for Fourier transform
 https://panteltje.nl/panteltje/pic/scope_pic/
or is a FPGA, ever higher frequencies, video DAC on FPGA I have here,
 https://panteltje.nl/pub/FPGA_board_with_25MHz_VCXO_locked_to_rubidium_10MHz_reference_IMG_3724.GIF
But for RF the good old LC Jfet makes a nice sinewave too, up to hundreds of MHz
There are many more oscillator types, crystal, ceramic to several GHz, that come close to a sinewave
for example as local oscillator in satellite LNBs, 2 ceramic resonator oscillators here:
 https://panteltje.nl/pub/5_dollar_LNB_PCB_IMG_3582.GIF
Some chips even output a sine wave, old modem chips

Not to mention my Fazley keyboard... press a key for a note,
you can select 'distortion' by selecting an instrument.

more:
 https://panteltje.nl/pub/44kHz_xmtr_circuit_diagram_IMG_4079.JPG
                                           
more:
 https://panteltje.nl/pub/44kHz_xmtr_circuit_diagram_IMG_4079.JPG
 https://panteltje.nl/pub/musical_gui.gif
 https://panteltje.online/pub/6MHz_xtal_oscillator.gif
 https://panteltje.online/pub/2.4GHz_twisted_oscillator_IMG_3629.GIF
 40_mV_oscillator_IMG_3597.GIF
  that is a JFET

There are many more....