RE: I've lost my k. Can someone help me find it?

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

Original poster: "Lau, Gary by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Gary.Lau-at-hp-dot-com>

THANK YOU (please pardon my shouting) for performing and reporting on such
a detailed experiment.  The alleged coupling "sweet spots" have long been
suggested to theoretically be significant, but it's also been my
observation that performance simply increases with increasing k until
racing arcs occur.  Time to retire this to the "coiling myths" graveyard.
Hey, there's an idea for a useful web page!

Regards, Gary Lau
MA, USA


>Original poster: "Daniel Barrett by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <dbarrett1-at-austin.rr-dot-com>
>
>    Hi List-
>
>    Thanks to everyone who helped me find my K. I spent about 3 hours with
>my single-MOT coil  today constructing an arrangement to vary my secondary
>height. I carefully measured K12 at each 1/8" interval beginning with the
>bottom turn of secondary 1/2 inch below the primary plane, all the way up to
>4" above. Armed with this spiffy spreadsheet we went out to the backyard to
>play. After trying all the variations I came to the following conclusion:
>
>    "It just doesn't freekin' matter."
>
>    I don't see any sweet spots, nulls or anything exciting at all. Arc
>length appears to be proportional to K until it gets so high that racing
>arcs occur and corrona starts coming out of all the bits it isn't supposed
>to.
>
>    I get arcs about 60 inches (at 1.4kW) with k at about .19 and racing
>sparks above about .21.  My observations suggest that K is not something
>worth tweaking, at least not as important as detuning to compensate for
>streamer loading, spark gap, etc.
>
>Is this consistant with what others are seeing?
>
>Does it become more critical at higher power levels or other conditions?
>
>db