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Best sparks



----------
From:  terryf-at-verinet-dot-com [SMTP:terryf-at-verinet-dot-com]
Sent:  Friday, July 03, 1998 11:12 AM
To:  Tesla List
Subject:  Re: Best sparks

Hi Richard,

you wrote:
>
>
>----------
>From:  Richard Hull [SMTP:rhull-at-richmond.infi-dot-net]
>Sent:  Wednesday, July 01, 1998 11:58 PM
>To:  Tesla List
>Subject:  Re: Best sparks
>
>
>
>Tesla List wrote:
>
>> ----------
>> From:  terryf-at-verinet-dot-com [SMTP:terryf-at-verinet-dot-com]
>> Sent:  Tuesday, June 30, 1998 8:49 PM
>> To:  Tesla List
>> Subject:  Re: Best sparks
>>
>>         What I suspect is that once the arc breaks out, it needs additional
>> current very quickly to sustain and help the arc.  In order to get this
>> current out fast, the top capacitance should be able to deliver charge at
>> maximum speed.  This event is fairly local to the top terminal and the
>> surrounding charged space.  There should not be too much coupling back to
>> the secondary ground except by capacitance around the secondary.
>>         It is obvious that arcs have very powerful high frequency
>> oscillations.  We don't quite understand why but it is probably best to help
>> those oscillations occur.  When the top discharges at high speed it may be
>> causing high local field stresses that help push the arc to greater
distances.
>>
>>         Terry Fritz
>
>I think the source of most of the high frequencies were identified over a
year ago
>on this list.  It is the arc itself creating a new resonating antenna of
its own
>every varying length.  This is most definitely modified by the large terminal
>capacitance.  Tesla noted similar happenings in his 1899 Colorado Springs
notes.
>Typical ranges are from a low of 5mhz to a high of over 200mhz.  Depending
on about
>a billion variables.
>
>I hope no one still thinks that the resonant frequency of the coil is the
frequency
>of all the electrical energy the visible arc channel of a TC!  Lots of pure
>unpulsating single polarity DC is to found in and around sparking TC's also.
>Remember the TCBOR electrometer measurements of 1996 and 1997?  The 100 gram
>rotored DC electrostatic motors run up to 500 rpm using a tesla coil in
1997?  The
>charging of a .1uf, 30KV capacitor from a TC in 1996?   A TC at full tilt
outputs
>DC to light!  Many of the mechanisms are supposedly well understood.  All are
>simple physics laws coming into play in an insane web of chaotic, naturally
self
>adjusting, multipathed events over often microsecond and submicrosecond time
>frames.  Attempting to following all the paths will simply make you nuts
>
> Lightning is a prime example of self excited resonating arc channels.  The
>hundreds of streamerlets, leaders, etc give lightning a very wide range of
>frequencies.....DC to light!
>
>Richard Hull, TCBOR
>
>


My experiment that I wrote the paper on concerned very short arcs to ground.
Assuming the 1/4 wavelength of the arcs was 3 inches, the frequency would
work out to ~1000 MHz from the arc channel antenna mechanism you mention.
Far too high to explain the frequencies I was seeing. 

A spectral analysis of the arc envelope indicates there are three
frequencies that make up the arc.  They are at 7,17 and 33 MHz.

Actually, I eliminated 999,999,997 of the billion variables and I do know
what causes them.

The 7 MHz component is the discharge characteristic of the 12 pF top
terminal and the arc resistance.  1 / ( 2 x pi x r x c ) which is 1 / ( 2 x
pi x 1200 x 18pf ) which equals 7.4 MHz in the experiment.

The 17 MHz component is the similar effect from the small sphere I used to
hold the discharge rod (shown in the paper) It is 8pF at 1200 ohms arc
resistance.

The 33 MHz component is what has me concerned and started the original post.
I believe it is caused by the top terminal running out of current delivery
capability and starving the arc.  If true, then fixing the top terminal so
that it can deliver the current smoothly should help the arc.  Thus, my
original question concerning how different terminals affect the arc character.

I have seen very high voltage fields produced by arcs.  Much higher than the
original top terminal voltage.  I am trying to find a way to optimize this
effect and try to get longer arcs.  I suspect that discharging the top
terminal with maximum efficiency will help this effect.

Although there are many frequencies and DC charges hanging around TCs, I
find that they are not DC to light.  There are only a few big peaks here and
there.  I have followed all the frequencies to their source but I still have
not gone nuts.  But I am still trying! :-))

Best regards,

        Terry Fritz