Re: First Light for 10" Coil.

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

Original poster: "Dr. Resonance" <resonance-at-jvlnet-dot-com> 


John:

I think it's simple physics.  The top closed turns of the coil act to shield
the electrostatic field from the underside of the toroid.  This will cause a
10-20% reduction in the toroid's measured isotropic value.

D.C. Cox



Dr. Resonance

Resonance Research Corporation
E11870 Shadylane Rd.
Baraboo   WI   53913
 > toroid capacitance when placed on the TC secondary. This capacitance is
much
 > less than the toroid capacitance calculated by the standard equations.
Why??
 >
 > For example with your coil the 12"x42.5" toroid capacitance using the
 > standard toroid equations is about 47.4 pf. This will not agree with the
 > actual toroid capacitance when it is located on the secondary. The actual
 > toroid capacitance is 34 pf which gives the 84.8 KHz (you measured). The
 > only way to find this actual toroid capacitance when it is on the
secondary
 > is by measuring the operating frequency with and without the toroid after
 > the coil is built. You then calculate the resonant frequencies with and
 > without the toroid. All of the surrounding conditions that affect the
toroid
 > and secondary capacitances will then be accounted for.
 >