[sdiy] Differential Pair

[patchell]

    The latest incarnation of the VCO (this circuit will be tested in about a
week, PC boards that have one of the VCO's on it are due in about a week) is
here: http://www.silcom.com/~patchell/seqproj/1001013.pdf

    I just hope there aren't any mistakes in the circuit... :-)

    I did make changes from the last version (that was tested) in the way the
temperature is measured, and the way the voltage source for the Rbe
compensation is generated.

Scott Bernardi wrote:

> Do have an example of the rbe compensation?
>
> patchell wrote:
>
> > Laurie Biddulph wrote:
> >
> > >    My synth VCO used a temperature compensated differential pair in
> > > the form of the uA726 which appears to have gone in to the archives
> > > alongside the dinosaurs (extinct). The MAT02 seems to be the first
> > > replacement of choice here but has anyone looked at the LM194/LM394 or
> > > are there any other alternatives to consider as well as selecting two
> > > trannies from the drawer?
> > >
> > > Best Regards
> > > (Mr) Laurie Biddulph
> > > http://www.ozemail.com.au/~boobies
> > >
> > > Tel: +61 2 4340 1525
> > > Fax: +61 2 4340 0936
> >
> >     The LM394 is also a good choice, as well as the MAT04...But, to tell
> > you the truth, I have made quite a few measurements involving the CA3046
> > (LM3046), and at about $0.50 each (at least here in the states), you are
> > not going to find much more bang for the buck.  I have been getting
> > about 1 to 2 cents log conformity over 8 octaves (using the compensation
> > for the Rbe).  Plus, I have been using it with an electronic
> > compensation, which means no heaters, and no temp compensating
> > resistors, with good results (not perfect, but pretty dang close).
> >
> >     I am pleased enough with the CA3046 that I will not be ordering any
> > more MAT04's, which are $7 each now (when I bought mine, they were $4
> > each).
> >
> > --
> >  -Jim
> > ------------------------------------------------
> > * Visit:http://www.silcom.com/~patchell/
> > *-----------------------------------------------
> > *I'm sure glad Merry Christmas comes just once a year
> > * -Yogi Yorgensen
> > ------------------------------------------------
>
> --
> Scott Bernardi
> sbernardi at attbi.com

--
 -Jim
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* Visit:http://www.silcom.com/~patchell/
*-----------------------------------------------
*I'm sure glad Merry Christmas comes just once a year
* -Yogi Yorgensen
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