1/4 Wave Theories - What now?
From: Robert W. Stephens [SMTP:rwstephens-at-headwaters-dot-com]
Sent: Wednesday, June 03, 1998 10:56 PM
To: Tesla List
Subject: Re: 1/4 Wave Theories - What now?
> To: "'Tesla List'" <tesla-at-pupman-dot-com>
> Subject: 1/4 Wave Theories - What now?
> Date: Wed, 3 Jun 1998 20:23:14 -0500
> From: Tesla List <tesla-at-pupman-dot-com>
> From: Malcolm Watts [SMTP:MALCOLM-at-directorate.wnp.ac.nz]
> Sent: Tuesday, June 02, 1998 4:53 PM
> To: Tesla List
> Subject: Re: 1/4 Wave Theories - What now?
> Hi All,
> > From: D.C. Cox [SMTP:DR.RESONANCE-at-next-wave-dot-net]
> > Sent: Monday, June 01, 1998 12:30 PM
> > To: Tesla List
> > Subject: Re: 1/4 Wave Theories - What now?
> > to: Terry
> > I think most of the capacitance is turn to turn but it would be very easy
> > to test your theory. Measure the cap of a secondary inductor and then
> > elevate it approx 25-30 feet above ground (in a sense isolate it from any
> > nearby ground plane) and then measure the capacitance again. If the cap is
> > turn to ground the value should diminish considerably --- if the cap is
> > turn to turn as I suspect the value should not change very much. You could
> > elevate it on some plastic spools, a wooden pole, or even a bunch of
> > cardboard boxes stack up high. A simple test that will validate your
> > theory or invalidate it.
> > DR.RESONANCE-at-next-wave-dot-net
> I have actually done this with a number of coils and Cself does
> diminish. I think there is a point where one runs into a law of
> diminishing returns though. Typically, one still has a lead running
> up to the base of the coil in order to drive it for measurement
> purposes and this itself adds capacitance to the system. This is
> precisely the problem Tesla ran into when trying to measure the
> capacitance of elevated "isolated" spheres. They were never truly
> isolated and Richard Hull made some interesting observations about
> this in the Guide to the Notes. Perhaps he could say more about this.
> Also, the further the coil is elevated, the smaller is the fractional
> distance moved from ground.
Instead of a bare conductor run from your test equipment to the
resonator which you are raising above ground plane, use a long piece
of flexible coaxial cable like RG-8. Coiled up on the ground or
extended vertically in the air, the center conductor will provide a
constant capacitance to earth. You can easily subtract this constant
term from your experiment to isolate the coil self-C.
Robert W. Stephens
Lindsay Scientific Co.
RR1 Shelburne, ON Canada L0N-1S5
Tel: 1-519-925-1771 Fax:
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