Equal Value Superhet Tuning Capacitor Tracking Calculator 
Instructions
3-1-2009 - Izzy Weird

Select the maximum variable capacitor value, Cmax(LO,RF)
in Farads (i.e. 365E-12).

Select the desired IF frequency, IF (kHz)(i.e. 455).

Enter a value for C Step that causes dial scale 30
to reflect the usable upper range of the tuning capacitor 
(C Step is usually around .90 to .99).

Or first select an RF inductance (or antenna coil) value, L(RF), 
to give you the lowest desired frequency (dial scale 1)
in the RF(kHz) column, and then select a C Step value
that gives you the upper frequency in the RF(kHz) 
column.

Now work with different values of L(LO),  C LO Trim, 
and C LO Pad to obtain acceptable tracking as viewed by
the graphs.  Observe the relationship of these components
to the amount of tracking or mistracking.

The circuit modeled is a variable tuning capacitor and a
trimmer capacitance in parallel.  The padder capacitor
is in series with this parallel combination.

This spreadsheet has been checked for accuracy, but
is not guaranteed to be error free.

Good luck.