more frequency tracking..

[Ethan Duni]

anyone have any thoughts on using a PLL to extract a clean sine from an
arbitrary signal and then running that across a series RC, tapping off of
one of the components then running that to a buffer and then rectifying and
filtering to get a frequency tracking CV?  how large a delay is usually
introduced in a PLL before the VCO matches the input frequency?  which PLL's
have the lowest delay?

Ethan