@Bolt:

Hehe Kapanadze in fact used a 9 Volt battery to start up his device in his latest demonstration, so you are right, he mastered it.

http://peswiki.com/images/d/d9/TMZ_black-box_Kapanadze_bulbs_300.jpg

You said something interesting in an earlier post :

Quote

QuoteThe input circuit is very simple high voltage  oscillator running around 1500 volts  to coil cap LC resonance with a spark gap in the feed back loop of the primary.

Would that automatically adjust the spark gap frequency to the resonance frequency of the primary coil through the feedback (kinda like a guitar feedbacking with the amplifier?)
Would you use a small sense coil to do that feedback part of it?
I am currently pondering about a circuit to control the frequency of the spark gap and this would be ideal if it worked. 
Otherwise the resonance of the primary would have to be measured with an oscilloscope and then the control frequency adjusted to that exact frequency which is more complicated.

What do you think about the fact that Kapanadze used conic coils? Does that attribute to the excitement effect?

Thanks for your brainstorming input into the discussion here. It really helps advance this.

Regards,
Xenomorph

Re: conical

My thoughts:

If you hit a tuning fork or pluck a guitar string, it will resonate with (only) one particular frequency called the “fundamental frequency" or "first harmonic” (= a sine wave) plus a few additional, higher harmonics.
This particular resonance-frequency â€" the so called first harmonic - is the direct consequence of the mass and shape of the “resonator” (guitar string or tuning fork in this example).

Now one could ask: how would a tuning fork which can resonate with several basic frequencies look like?
I don’t know the answer. Is it even imaginable?

But things with the ability to resonate with lots of different frequencies (amplifying the output) do exist. Examples for such “broadband resonators” are a violin or a piano (not talking about the strings now, but about the resonating body of the instrument)

Ok. So that’s that.
Now let’s look at Kapanadze’s circuit. The sparkgap is in the driving part. It creates bursts with a certain sequence. Some contributors in this thread think that these bursts are produced at a stable frequency of 50 Hz and that the displacement currents in the line between the two grounding spots will also oscillate at basically that frequency. But I think the crazy hiss at the beginning of one of the videos clearly is no 50 Hz signal. In fact I believe that the sparkgap fires more or less with a randomly unstable frequency (something like white noise). The hissing sound at the beginning of the video even contains frequencies which are able to jam the sound processing system of the camera.

Now let’s build an efficient pick-up coil for such a signal.
The coils we are used to are not conical but cylindrical.
These usual coils with their wire loops of equal size (=cylindrical shape) do well resonate to (= pick up) one particular frequency (= sine wave). Just like a tuning fork.
This normal coil characteristic - resonance with a sine wave of a certain frequency - is very convenient ito tune in to a signal source with a distinct and stable frequency (radio), or if you want to build a (normal) transformer to transform “grid power” as the grid signal also comes as a stable sine wave.

But if you are faced with an incoming signal from a source that sends out a fluctuating frequency or a “broadband signal” or some crazy wave form coming from a spark gap? How to pick it up efficiently in order to transform it? How to build a resonator for it?

I guess such a coil would have to have loops of varying diameter.
Sort of like a cone.

And it just dawned on me that Tesla’s pancake coil can be understood as a cone with zero height.
Would he have invented it as a transmitter/receiver of a non-sinewave signal? A signal we today would classify as noise (but which contains a lot of energy)?

If someone equipped with a scope can scope the frequency of a sparkgap, that would be nice to see.

Spark Gap in free air is not HF device. Only 50 - 500 Hz.

"In a spark gap Tesla coil the primary-to-secondary energy transfer process happens repetitively at typical pulsing rates of 50â€"500 times/second, and previously formed leader channels don't get a chance to fully cool down between pulses."

http://www.answers.com/topic/tesla-coil

Spark Gap Tesla Coil is HF device:

http://4hv.org/e107_plugins/forum/forum_viewtopic.php?65393.post

In Kapanadze glass box I see magnifier TC, as its:

http://www.youtube.com/watch?v=o7YnoYsCPiw&feature=channel_page

"small copper ring" probable is the first and second winding, third winding = "long copper pipe"

Quote from: Sergh on July 13, 2009, 07:07:08 AM
Spark Gap in free air is not HF device. Only 50 - 500 Hz.

Hi Sergh,
thanks for the info.
But please be aware that these are burst per second, i.e. proper disruptive discharges each with non-sinusoidal waveform.
If you would calculate a Fourier-transformation to find the underlying sine-waves, i.e. the sine waves which are inherent in the bursts, you would probably find something like "white noise".

You are going off into speculations and pondering again. These TESLA systems are not secrets they are open published for 100 years many are expired patents (most in fact).  No need to wonder what frequency to use? or what the coil looks like? or how many turns ? or how big is the spark gap?

i mean heck just use a car spark plug and ignition coil!

Go and read about Don Smith he built all of tesla systems over 20 odd years and explains everything with circuits included.