RE: Frequency splitting (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Mon, 20 Aug 2007 10:52:21 +0100
From: Colin Dancer <colind@xxxxxxxxxxxxxx>
To: 'Tesla list' <tesla@xxxxxxxxxx>
Subject: RE: Frequency splitting (fwd)

Hi Jared,

As you say you can model a streamer as a wire with non-linear resistance,
but I'd suggest any such conductor will also have finite inductance and
capacitance.

Using standard formulae you can calculate that a 0.1" dia wire 6' above a
ground plane has a capacitance of ~0.17pF/inch and an inductance of
~40nH/inch. 

(We can argue whether 0.1" is the correct diameter, but this term appears
inside a ln() so the final figure is not that sensitive to changes in
assumed size.)

So very roughly, 72" of streamer (to a first order we can probably ignore
branching effects) might add ~12pF to the topload capacitance.

Depending on coil size this might well be a very significant change in
capacitance and hence tuning.

Colin.
-------

Commentaries:



It has come to my attention that many experts on Pupman are now describing
the plasma arc from the secondary capacitor  as having a capacitance. They
are tuning coils as if the capacitance was really there.



There is no such capacitance in the arc. Capacitors do not increase
capacitance when they arc out. Arcs do not have an ability to store charge.
Arcs  do not have plates nor can they be described with a fixed geometry.



Nor can we describe an arc as having an appreciable inductance. The geometry
is not much good for inductance.



Nope!;  you are altering C or C'  to make up for changes in frequency caused
by dampening. (dampening from  the non linear resistance of the arc)



Empirical corrections are wonderful, my hats off!  I am sure that a great
deal of effort was involved in arriving at a useable correction factor. But
there is no capacitance in the arc. There is only non linear resistance and
perhaps a tiny bit of inductance.





Jared Dwarshuis  August 07