Re: Safety gap issues

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Mddeming@xxxxxxx 

Hi JT

In a message dated 11/24/05 9:14:13 P.M. Eastern Standard Time, 
tesla@xxxxxxxxxx writes:
Original poster: "JT Bowles" <jasotb@xxxxxxxxxxx>

Use a counterpoise? You mean putting large amounts of al foil, spread
on the ground, as an RF ground? WTF no way dude, that ruins the
aesthetics of my coil.

A solid counterpoise wastes a lot of power in eddy currents. The most 
efficient form is a large number of wires set radially from the 
bottom of the coil like the petals of a daisy.

i DO have a 4 foot Cu pipe driven into the ground, and 15 feet of
wire is attatched to it.
*I use this separate ground as a ground for the sparks to jump
to.(from toroid directly to this)

*I have read all over, 1 inch requires around 25,000 volts to make a
spark connect. So, i have been measuring EVERYTHING using this
equation. IN OTHERWORDS, I USE 1MM=1000V. My sparkgap is set at 7.5
to 8 mm, thus 7.5 to 8 kV

Then read more carefully and thoroughly. It is true only at fixed 
pressure, temperature, humidity and composition of the air, and then 
only with quasi-infinite electrodes for uniform field. The first 
three change day to day, and you lose the four parameters as soon as 
the gap fires for a few seconds.

* my output is 15.5 inches- so i times that by 25,000 volts per inch-
to achieve a staggering
388KV tesla coil output

ONLY true for the very first pulse. After that, the repeating RF 
pulses cause the streamer to grow. This is the whole advantage of HF 
Tesla coils: the streamers grow much longer than voltage alone would 
indicate. Again one needs to read AND understand the whole law, 
including its restrictions before quoting it as gospel. Your output 
estimate is probably double the voltage you're really getting.

Hope this helps

Matt D.