Re: Why the primary is a flat spiral?

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

Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>

Flat spirals:

1) look neat
2) easy to wind (compared to conical)
3) allow easy adjustment of coupling by raising/lowering secondary (doesn't
work so well with helical primary)

4) Provides a nice ground plane for the topload to work against so that the
field is even, reducing odds of weird sparks.

Tesla list wrote:
> 
> Original poster: "Shaun Epp by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<scepp-at-mts-dot-net>
> 
> I did a demonstration to a group of Ham Radio people I know this evening and
> it went really well.  I demostrated the spark show, burning / stripping a
> CD, tube light lite from a distance and on top of the coil.  They where all
> impressed, I even recieved  a round of applause   : ^ ) .  One woman asked
> me why the primary coil was flat and I was somewhat stumped.  I just
> explained that its used to couple the energy into the the secondary.  Now
> I'm wondering what to tell the next person, something to do with coupling?
> 
> What other stage tricks do others do?