In the VHF/UHF Handbook, chapter Receivers, Transmitters And Transceivers ,
section, 'Tuned Circuits'; the author writes: "If discs are used, the
capacitance varies in a very non-linear manner with the distance between them.
It is: C(pF) = 0.00885 x Area (sq mm) / Spacing (mm)"
The equation for capacitance vs area vs spacing is linear. What's up?
John, N9RF