[sdiy] Matching across matched pairs for dual VCOs

[Aaron Lanterman]

Suppose you were building two VCOs that you wanted to be able to track  
one another pretty well, say for yummy FM goodness.

Would there be an advantage to using, say, something like a THAT chip  
that has _four_ matched NPNs, so that your two expo converters would  
be matched with each other and also stay at the same temp?

Or would other sources of error between the circuits swamp such  
effects and make it not worth bothering with?

- Aaron