[sdiy] 4046 VCO

[Matthias Herrmann]

for the thomas henry VCO we found that some brands completely failed and the VCO
was not scalable to 1V/oct. they always came short.

Scott Stites:
"The CD4046 ICs that I found to be more compatible with the design would list
the following as the VCO linearity specification:
- At 15V Operation, VCO In = 7.5V, +/-5V, R1 >= 1M: Linearity = 1% 

The few CD4046 ICs that I found to be less compatible with the design did
coincidentally list the following as the linearity specification:
- At 15V Operation, VCO In= 7.5V, +/-1.5V, R1=100K: Linearity=0.5% 
- VCO In= 7.5V, +/-5V, R1 = 1M: Linearity = 7% 

The particular brands of CD4046 I found to tune more easily/consistently are as
follows:
- National CD4046
- Fairchild CD4046
- Motorola MC14046"
(from
http://www.birthofasynth.com/Thomas_Henry/Pages/X-4046.html#Miscellaneous_Notes)

I had good experiences using the NXP part.

Cheers,
Matthias