Re: 3/4 wavelength secondaries

Tesla List wrote:
> >From ed-at-alumni.caltech.eduTue Jul 30 22:26:56 1996
> Date: Tue, 30 Jul 1996 16:52:31 -0700 (PDT)
> From: "Edward V. Phillips" <ed-at-alumni.caltech.edu>
> To: tesla-at-pupman-dot-com
> Subject: Re: 3/4 wavelength secondaries
> Question: Why the interest in free-space wirelength?
>         There have been a lot of listings here lately in
> which it appears that the author thinks there is something
> "magic" about having the coil operate near the free-space
> quarter-wave resonant frequency of the winding.  I can't see
> what difference this really makes, as long as the coil is
> excited at the correct resonant frequency as determined by
> self and lumped (top terminal) capacitance.  Am I missing
> something?
>         One other point.  Although I don't remember seeing
> it expressed explicitly, the effects of a top toroid are
> at least twofold:
> 1. The L/C ratio of the secondary is lowered, reducing its
> surge impedance and hence the loss of Q for a given power
> lost in discharge.  Seems to me this should increase the current
> when the discharge starts.
> 2. The breakdown voltage is increased, increasing the formation
> of the streamers which finally carry current when breakdown
> occurs.  In the case of one of my small coils, this effect takes
> seconds.
>         Any comments from the
>         "Richard's"
> or anyone else?
> Ed Phillips

Ed Phillips and all:

I think that I started all of this and the reason I asked the original 
question was because as I wound coils in which the wire length approached
the 1/4 wavelength of the resonant frequency, there seemed to be an 
increase in the discharge length which I could not attribute to any
other factor. I also found it impossibe to actually wind a coil which
has a resonant frequency equal to the wire length. Whether there is any
magic in the 1/4 thing is still very much a matter of conjecture to some
of us.