SV: Re: National AN-299 VCO idea (was: Re: [sdiy] Exponential converter information)

[karl dalen]

--- Ian Fritz <ijfritz at earthlink.net> skrev:

> At 08:48 AM 6/19/05, synth at oldmail.charlielamm.com wrote:
> >Nice links....I esp. like this one:
> >
> >http://www.national.com/an/AN/AN-299.pdf#page=1
> >
> >Has anyone actually messed around with this? i.e., can you really use a
> >LM3046 and the temp dependence of a polystyrene cap as they show here, to
> >cancel temp drift of a VCO?
> 
> I haven't tried it yet, since I don't really like the heater approach 
> (where does the heat go, and what does it do?),

I have tried it and didnt like it!
I like the heater aproach, but prefer the Moog Source method.
The heat goes to the air,after it heats the trannies, you know that Ian!
 
> but it looks OK.  If the 
> poly cap doesn't cancel the linear drift completely, you can take out the 
> difference by adding a small dc voltage at the input to the converter 
> transistor.

I dont like the NS aproach to VCO design its ackward and limited, the
basic standard ASM ,MOOG, or MS20 aproach are much more convenient! 

REG
KD