RE: A photographic tutorial of Pancake Coil winding...with movies...(fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Fri, 22 Jun 2007 07:12:37 -0500
From: David Thomson <dwt@xxxxxxxxxxxx>
To: 'Tesla list' <tesla@xxxxxxxxxx>
Subject: RE: A photographic tutorial of Pancake Coil winding...with
    movies...(fwd)

Hi Bart,

> >Bart just pointed out that the metal pipe you are using acts like a 
> >waveguide, or third coil.  

> Just the opposite. A third coil not in resonance acts more 
> like a capacitively coupled topload object and the dimensions 
> of the coil. The third coil is pretty much a pipe at that 
> point. In Jeff's case, it's nothing more than a topload 
> object. In your coil, the solenoid is acting like Jeff's pipe 
> (just a topload object).

It may be an opposite perspective, but it is the same thing, either way.

A third coil has no inductive coupling with the secondary and acts like a
Helmholtz resonator.  

If my understanding is correct, anybody can replace the third coil on their
magnifier with a copper tube of the same dimensions and get the same
results.

Dave