[HBR] Reducing variable cap values

[Ian Wilson]

Been looking through my air-variable capacitor collection.

All the ganged capacitors that I have are considerably higher in value
than what the BHR would like.
So I took a look at reducing capacitor value.

Using a single series capacitor doesn't work too well, since the nice
square law that the original capacitor has is lost, and most of the
variation is squashed into the low-C end of the variation.

I have been playing with a 3-capacitor arrangement: the first in series
with the variable, the second in parallel with that combination, the
third in series again. Thought that would get me some degrees of
freedom; however, doing a curve fit didn't get me a very good result.

Any sages out there have advice on how to reduce the variable's value
(without removing vanes!), and still getting a useful
capacitance-versus-rotation curve?

73, ian K3IMW