[sdiy] small VCO core (was Temperature stable lin-expconverter with a CA3086 or CA3046)

[patchell]

    I guess I should chime in with one I did a couple of years ago now as
well....
http://www.silcom.com/~patchell/jp2rest/dualvco.pdf

    Actually, maybe I should resurect that project.  I have quite a few of the
now discontinued THAT140s which would put them to good use.

Ian Fritz wrote:

> There are indeed several advantages to using a TRI core. The CEM3340
> literature explains these quite well. The TRI #2 VCO on my site has
> excellent performance mainly due to not using an OTA chip and to using
> high-quality modern components. I also show a novel TRI-SAW shaper with
> only miniscule glitches at the switching points due to the switches being
> driven from the VCO core directly rather than from derived signals. T
> compensation is also discusssed.
>
>    Ian
>
>    http://home.earthlink.net/~ijfritz/sy_cir4.htm
>
> At 11:55 PM 5/27/2002, jorgen.bergfors at idg.se wrote:
>
> > > It would be nice to have a core VCO design. Just an
> > > expo convertor and a sawtoth oscillator.
> >
> >Why sawtooth? My recent experiments show that it is much easier to shape
> >other waveforms from a triangle core.
> >Also, a triangle VCO doesn't have the problem with the sawtooth reset time.
> >Mine stays in tune to over 20kHz, without any HF compensation whatsoever.
> >
> >/Jorgen

--
 -Jim
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