The simpler answer - L1+2 inductance = -L3+4+5+6 .. This is what we aiming for with
winding/unwinding L5+L6 for reaching total inductane close to 0
And the standing wave have to be under inductor of grenade which makes scalar field there.
You have two types of inductance (magnetic and dielectric) and two types of waves (TEM & LMD)
active here. LMD waves have no magnetic component so only the wire length is of any consideration
for those. We can be pretty certain TEM waves in the grenade coil propagate slower since they do
have a magnetic component.
I see this as a process of combining two types of waves. In understandable terms, magnetic is current;
dielectric is voltage. LMD waves are purely dielectric; TEM waves are both dielectric and magnetic.
The push/pull produces purely TEM waves. The Telsa secondary produces TEM waves also, but is
filtered by the bucking coil ferrite rod, leaving mostly LMD waves at the Tesla extra coil (antenna).
BTW, the large spherical cylinder on a typical Tesla coil device is also a filter of TEM waves.
Now to get mixing in the so-called standing wave, we have to have the correct ratios; part of this
depends on the load applied to the grenade coil since it is well known BEMF from the load will
induce a magnetic field in the grenade and disturb the standing wave. That's what current flow
does. So the LMD wave at the antenna needs to augment this current flow in-phase. And at
the same time, layers 3,4,5,6 must magnetically buck half of layers 1,2. Those magnetic
lines of force must cancel out, leaving only the magnetic lines of force under the antenna.
This is where things get a little tricky due to the shape of the grenade coil--where are the
magnetic lines of force? Layers 1,2 are in-phase and only partially bucked by layers 3,4,5 & 6.
Under no load conditions, layers 1,2 are almost completely bucked by layers 3,4,5 & 6. No
BEMF, no current; that one is easy.
Under load, now it's not so easy, because we don't know exactly how these magnetic lines
of force mesh. We can guess most of them cancel furthest away from the antenna. Under
extreme load, the lines of force extend past the antenna and the system stops functioning
because now the TEM and LMD waves are completely out of phase. Here the Tesla coil
would actually hinder the output instead of augment it. By design it would appear the
grenade coil is actually self regulating--current is automatically reduced when the magnetic
lines of force extend into the region of the antenna.
I'm probably not making a lot of sense in all this, so before I get labelled as a kook, I'll stop
here.
A couple of ways to trigger a Tesla coil; one creates a ringing, the other does not:
http://www.st.com/content/ccc/resource/technical/document/application_note/af/27/67/e5/fe/17/48/95/CD00003947.pdf/files/CD00003947.pdf/jcr:content/translations/en.CD00003947.pdfGuess which one works better for this application.