[sdiy] VCO tempco R locataion

[Ian Fritz]

At 02:01 PM 7/30/2010, JH. wrote:

>In feedback loop of opamp means no such error (low impedance), but it also 
>means the opamp's input noise appears at the transitor base without 
>attenuation, which may or may not be a good thing, according to your 
>desigh philosophy.

Yes, and additionally the opamp offset voltage leads to a temperature 
drift.  So it is really a good idea to spend for a high-performance opamp 
with this method.

   Ian