Re: 1/4 lamda and intial sec design parameters

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: Ed Phillips <evp-at-pacbell-dot-net> 

"Using a large top load capacitance, ie 2-4 x the dia. of the sec coil,
helps
force the best resonant point near the 1/4 lamda point.  Also, the large
top
load, sphere or toroid, reduces considerably the values of the minor
resonances and allows the experimenter to get maximum gain and
performance
at a single frequency.

German experimenters first published these ideas in the 1930's--- most
of
the publications are written in German but one can clearly see the large
toroids they used on resonance transformers.  Tesla of course using some
toroids to keep his ceiling exit point (his high antenna) from setting
his
wooden pole building on fire, but the German group was the first to see
it's
value to control the electrostatic field of the sec. inductor and reduce
unwanted resonances."

	I think it's simply that the top loading made the equivalent circuit
approach that of a single lumped LC.  Of course, it lowered the surge
impedance as well which was almost certainly beneficial.

Ed