[Antennas] Loading inductances

[Harvey&Bessie]

I wouldn't do that at all, unless you like to spend time with a hit-or-miss experiment. 
Beg, or borrow an antenna bridge and measure the reactance of the vertical at the 
frequency you wish to use it on (it will be capacitive if shorter than 1/4 wavelength). 
Then using the formula in the handbook, calculate the size of the coil which will give you 
the required inductive reactance to balance out the capacitive reactance of the vertical.
Harvey/W4TG