Re: 1/4 lamda and intial sec design parameters (fwd)

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

Original poster: Tesla List Moderator <mod1-at-poodle.pupman-dot-com>



---------- Forwarded message ----------
Date: Fri, 16 Jul 2004 23:10:56 -0600
From: Gerry Reynolds <gerryreynolds-at-earthlink-dot-net>
To: Tesla list <tesla-at-pupman-dot-com>
Subject: Re: 1/4 lamda and intial sec design parameters

Hi Ed,

In view of previous posts, could you define your 1/4 lamda point?  Also, the
"minor" resonances you refer to, are these harmonics of the fundamental or
other spurious frequencies?  If not harmonic, then could you describe the
spurious mode (maybe an example)?

Gerry R

> 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
>
>