Re: TC Inductance Formulas...

	The procedure for coaxial solenoids in Grover's book
uses rather long tables.  (Procedure for calculating mutual
inductance between coaxial solenoids, that is.)  I have written
a program in Microsoft Quick
Basic (please excuse line feed) which incorporates Grover's tables
with interpolation, and works just fine.  Could send a copy to you
if you want to try to play with it.  Don't know of any approximate
formula or procedure for cases where the coils are of different 
	If you want I could send you a copy of this program, but
using it would involve either a lot of typing or else using a word
processor to get it so your Basic (if you use it) could read it.
	There are good formulas to approximate Nagaoka's constant
for calculating inductanc e, good to a few parts per million, if
you are interested in those.
Ed Phillips