Re: How to rise the secondary? (fwd)

---------- Forwarded message ----------
Date: Thu, 16 Jul 1998 08:58:13 +1200
From: Malcolm Watts <MALCOLM-at-directorate.wnp.ac.nz>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: How to rise the secondary? (fwd)

Hi Rob, Terry,

> Date: Tue, 14 Jul 1998 23:42:37 -0600
> From: terryf-at-verinet-dot-com
> To: Tesla List <tesla-at-pupman-dot-com>
> Subject: Re: How to rise the secondary? (fwd)
> At 10:18 PM 7/14/98 -0600, you wrote:
> >From: "Robert W. Stephens" <rwstephens-at-headwaters-dot-com>
> >To: Tesla List <tesla-at-pupman-dot-com>
> >Subject: Re: How to rise the secondary? (fwd)
> >
> SNIP>>>>>>>>>>>>>>>>>>>>>>>>.
> >
> >John,
> >
> >I hope you can be as suprised as I was when I made this physical test.
> Take an 
> >average TC that can produce a solid 8 foot discharge, even on holidays.  Take a
> >straight piece of copper wire, aluminum , steel or even a salty piss trail
> on an 
> >otherwise insulating rug  that equals the let's say 8 foot output spark length.
> >Electrically connect this conductor to your topload and suspend this piece of
> >straight outwardsbound conductor radially away from the topload of your coil
> >discharge terminal through the help of insulating nylon fishing line, or 
> >plastic barrels.  With an o-scope and signal generator measure the
> secondary Fo 
> >of the HV resonator before and after the introduction of this electrically
> isolated
> >streamer length wire representation model!
> >
> >Hint: If the software program you rely upon doesn't anticipate this 
> >experiment I suggest you test this effect in real hardware and find a 
> >way to include it's variability into your software.  It is rather 
> >significant!!!!
> >
> >I suggest that you will discover that a long streamer causes a great 
> >deal more than _insignificant_ tuning and loading effect upon a 
> >non-sparking Tesla coil.
> >
> >Richard Hull and many others of us with dirty hands now know this well from
> >the doing.
> >
> >Robert W. Stephens
> A very interesting post and idea!!!!  My models don't do this type of load
> effect but they probably should!  I hope it can be modeled as a lumped
> parameter :-))
>         Terry Fritz 

I conducted exactly this test three years ago when the loaded tuning 
phenomenon was first brought to my attention and found it to be
absolutely correct. The inductance of a straight piece of wire is 
significantly less than its self capacitance (compare a wound up coil 
with a 1/4 wave straight wire monopole). I have found repeatedly that 
tuning the primary below non-breakout tune produces longer sparks and 
the higher the power level one oiperates at, the more dramatic the 
effect. In effect, the coil pulls itself into tune with additional 
streamer capacitance. The fact that dissipative loading sucks Qs into 
the dirt when the loading is heavy is beyond dispute. TCBOR courtesy 
Richard Hull reproduced a scope photo I took of the secondary ring 
stopping abruptly after several cycles with an attached-to-ground