[sdiy] 4069 VCO linearity SUCCESS

[Scott Gravenhorst]

Hey René!

I got it working to 6 octaves:

0.074
0.147
0.296
0.593
1.191
2.390
4.869

Are the voltage readings I took while doing the period
halving test.

One thing additional I had done that made things worse:
At one point, I had gotten it sort of working, but it
was oscillating at such a low freq that I (not thinking
that something was WRONG) subbed the 2.2 nF cap for 
a 150 pF.  I grabbed a 3.3 nF and that seemed to fix
the nonlinear ramp.  I see the smallest of nonlinearity
at the very start of the ramp.  The 3.3 nF is also much
more compatible with the range of human hearing (c:

The last measurement is a little off, but that might be
because I had removed the 'high end' compensation
resistor/diode.  I'll put that back in and see if I can 
squeeze another octave out of it.  Over about 5.3 volts 
of CV the VCO stops oscillating.  No big deal, I can use
whatever linear portion I get and shift the freq around
by selecting an appropriate cap.

Very cool, René, thanks.

=========================================================  
- Government: The other religion.
- The media's credibility should always be questioned.
- Lambs who lie down with lions are lunch.

-- Scott Gravenhorst | LegoManiac / Lego Trains / RIS 1.5
-- Linux Rex         | RedWebMail by RedStarWare
-- FatMan: home1.GTE.NET/res0658s/TekLab_FatMan_WebSite/index.html