"John A" wrote in news:4666bbdc$1$8756$ed2619ec@ptn-
nntp-reader02.plus.net:

Well, I intentionally didn't suggest adding a variable as a) it would
re-open the Pandora's Box of how to calibrate the thing, and, b) the
combined tolerances of the fixed components would make a nonsense of such
calibration anyway.


Initially, I didn't assume the OP wanted a large variable capacitor at all,
but was mistakenly trying to match fixed sizes with variable sizes without
considering why such things are not common practise. Calibration aside, the
variable I suggested adding IS a viable idea, assuming your switched-cap
box is valid. After all, if you CAN get any value, then you set it as you
need. If it's tuning frequency, you measure the frequency.

But as I said WAy early in the thread, first reply, if you really want a
sweep of possible timing values, just use a fixed cap and a variable pot,
as standard. The OP was talking about synthesizers, after all, he mentioned
them explicitly.