[sdiy] 2164 Expo correction

[David G. Dixon]

> How about the current drawn by the measuring device? That 
> would lower the current through the 2164 for the applied 
> voltage. Or another way - the measurment device adding a load 
> to the source could reduce the voltage at the 2164 CV pin.

There's no current flowing into the VC pin to speak of.  As for the DVM
loading the pin, it might change the voltage by a few microvolts, but not a
millivolt, and I didn't hear a change of pitch when I touched the pin.