RE: How to Tune a Flat Spiral Coil

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

Original poster: "David Thomson by way of Terry Fritz <twftesla-at-qwest-dot-net>" <dave-at-volantis-dot-org>

Original poster: "Barton B. Anderson by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <tesla123-at-pacbell-dot-net>

>You lost me here. Are you saying that changing the primary inductance in
the tank won't tune the coil?

Hi Bart,

Today I fired up the trifilar coil and tried tapping the primary at 2.5
turns instead of the full 3.5 turns.  The frequency did not change and the
voltage went through the roof.  Actually, it snapped pretty strong through
the 1/4 inch Plexiglas and 1/4" hot glue.  I'm going to put another 1/4" of
Plexiglas under the primary for a total of 1/2" of Plexiglas and 1/4" of hot
glue.  The dielectric strength should be well over 500,000V.  And if this
doesn't work, I'll add another layer.

I did not have the 30" plates on the coil with today's test.

The plasma ball on top of the trifilar glowed red, instead of green, and 5"
tongues of bright plasma shot up from the base inside the plasma ball.  I
couldn't run it for long due to the breaching of the Plexiglas.

My test run is not conclusive, but it does suggest that the primary coil
does not affect frequency but only voltage.

Dave