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Re: stepped leaders

Hi Jim,
        You asked....

> Could I interject a thought on this condition? Under this condition,
> the TC secondary IS acting like an unterminated transmission line with
> the attendant high SWR that this condition implies. (Standing Wave
> Ratio can be thought of as the ratio of forward power to reflected
> power) With no load at the end of the transmission line (no sparks at
> the discharge terminal) and all the power sent down to the far end of
> the secondary is reflected back to the near, driven, end.
> 
> This reflected power is transformed by the transformer action of the
> TC secondary to TC primary coupling and is dissipated in whatever
> lossy components are in the primary circuit. Given most construction
> methods used by the coilers on this list, the primary is of low R, the
> cap is of low D, that leaves the spark gap as the losseist component.
> It starts dissipating the power of the system.
> 
> One of my unanswered questions: is the output voltage of the TC
> secondary: a) strictly the input voltage multiplied by the turns
> ration of the secondary to primary? b)input voltage multiplied by the
> turns ratio multiplied further by the 1/4 wave transmission line
> properties of the secondary? or c)some combination?  I am waiting to
> measure this until I can build some type of metering scheme; field
> mill or HV resistive divider.

I'd like to inject a note on this. First off, turns ratio is out. It 
applies only when the coupling approaches 1. Wave action governs 
secondary behaviour IMO. The easy way is thinking about the bathtub
scenario, where you give a wavefront sloshing between one end and the 
other a timed push at one end at the exact time it is starting to
head up the other end again. In this system, energy accumulates with 
each push in exact proportion to the push imparted. In principle, you 
can give it any number of pushes and it gets higher and higher. In 
practice, it is going to reach an amplitude where some of it starts 
spilling over the edge (energy loss - spark). If this didn't happen,
there is no theoretical limit to how high it reaches as long as the 
push is enough to overcome any loss with a bit to spare. The losses
may grow with amplitude (e.g. dielectric losses) so what started out 
as an adequate push ends up being inadequate to over come these 
losses and the system reaches equilibrium.
     Now for the fly in the ointment re our cap discharge systems. 
The push per cycle is not constant! It is in fact a decrementing push 
(primary ringdown). You can see that the energy accumulated in the 
secondary can only reach the level of that originally in the primary 
cap if no losses exist (gap ruins that ideal). It is easy to see that 
the voltage in a cap discharge system has a very real limit and that 
limit is the amount of energy originally contained in the primary cap
(minus losses in getting it transferred to the terminal). This is the
real scenario.
     **Speculation**  In fact it's not even that good. The line is 
less than a wavelength long, so energy is distributed along it. In 
fact you can estimate terminal energy in a "full" line by using the 
ratio of the two capacitances (line and terminal). If they are equal, 
the energy distribution must be equal. ** End Speculation**
        A CW system imparts a _constant_ push per cycle and there 
is no limit to the original energy source as there is with a cap. 
Both scenarios accumulate energy by the use of standing waves, but you
can only do so much with what you have.
     I am prepared to go on record here by saying that our systems 
look AS IF they are lumped circuits because you have a real capacitor
with a finite energy content trnasferring its contents to another
real capacitor. The manner of energy accumulation in the secondary is
NOT by lumped circuit action however. In a close coupled system, you
can only do as well as the turns ratio. In a delay line, you can pump
energy in endlessly IF you have an endless amount of energy to pump 
in by adding a bit more every cycle or half cycle and the line 
reflects what it has accumulated from one end to the other in the 
correct phase for the pushing circuit.

Sorry for shouting. I firmed up on these suspicions during my 
experimental period in the weekend. I think it is clear why Tesla
claimed that "no such pressures, even in the remotest degree" could 
be obtained from lumped circuits. I think it is also clear that the
line can only accumulate as much energy as there is available to
drive it.

Malcolm