Correcting my own post a bit...
> This signal (after differencing with the -7.0V highest "C" coming out of x6 of IC31)
This part is probably not true. I sometimes forget that IC31 is ∗after∗ the exponential converter. So, while I do think that it is true that x6 holds the voltage for the highest "C" produced by the Polysix, I don't know what the voltage is here.
Even if it was before the expo converter, I think that the voltage of highest C (by the time it gets to KLM-366) would be +3.5V, not -7.0V, so I was talking crazy anyway.
Sorry for any confusion.
My original question still stands, though...what the heck is happening in this part of the circuit? How does it cause the "stretched tuning" to be effected?
Thanks!
Chip