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Re: [TCML] Spark Length Measurement Techniques
Here's a scheme that I use to tune a coil to it's maximum spark
length which also yields an accurate measure the length achieved. I
tape a nylon weed-wacker line to the toroid and attach the opposite
end to a vertical support about 20 feet from the coil. Suspended
from the line are about 20 movable wooden dowels each pierced by
small nails at the lower end with the nail furthest from the coil
being grounded. An arc from a breakout point on the toroid will jump
from nail to nail to reach ground and so you just keep increasing the
dowel spacing an readjusting the coil until the arc cannot reliable
span the distance. Once the coil is tuned to achieve a maximum spark
length, all one has to do is measure the span and subtract the total
length of the nails.
Here's a picture this setup taken at Greg Leyh's Nevada Lightning
Laboratory last summer:
I certainly understand that references are needed and this can be
done to a degree, but with sparks, this gets tricky. In order for
the spark to be accurately measured via a photograph, the spark
"must be" perpendicular to the camera. Even a few degrees into the Z
axis, and the "object of reference and known dimensions" must be
reduced in size by the angle. All sparks that have any angle to the
camera from the perpendicular will always make the sparks shorter
than they actually are. 13M did not have a single perpendicular arc
in the photo taken. The only arc close is the one on the right that
issues from the back and curves around the coil forward. If you
measure with some known reference object, you still completely miss
the Z axis length. I don't believe this to be the claim photo as
I've already stated in the other thread, but represents my point
regarding Z-axis. Not only with the angle the spark issues, but also
it's curvature in that direction.
The best way of course is to never rely on a photo as the
measurement, but rather a measured "target" the coil arcs to within
a photo. Spark length claims without a photo are not proof, but this
doesn't mean the claim is false. It simply means you must take the
claimers words with faith that it is true or not.
My little coil 4.5"D x 21.165"H max spark length is 55" to a target.
At my front page of my website is a photo of this coil and an arc (top right).
The two toroids edge to edge nearest distance is 55" measured with a
tape measure. If you were to use a little stick man or other 2D
object, what would you estimate the distance to be? For reference,
the toroid on the little coil is 6.25" x 21".
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