Re: A 1/4 wave Tesla coil

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "B2 by way of Terry Fritz <twftesla-at-uswest-dot-net>" <bensonbd-at-erols-dot-com>

> Performance:
> Operating frequency: 280khz
> Spark length with no breakout tab: multiple arcs 48"(+)
> Spark length with breakout tab: single arcs 60"(+), very, very thick
> Interesting note: With no Cop, arcs are close to 42" from top terminal, but
> coil is obviously poorly tuned and much corona around top turns of secondary.

Hi Skip(1),
    I've seen John Freau's coil make sparks about this long with about half
as much energy (HTSTWMOE(2)).  It would be an informative experiment to
halve the primary capacitance and add a few more turns to the primary to
bring it back into tune (start with it undercoupled).  John Freau used #12
PVC insulated wire (machine tool wire?) for his primary with about 34 (?)
turns.  After seeing this I will never build a subpig system with copper
tubing.

Cheers,

Barry

(1) I used 10 of the 1/2 watt carbon film resistors (Radio Shack) with 35
kV DC across them for several hours and they didn't cook!  
(2)HTSTWMOE-Had To See That With My Own Eyes