Re: Space winding

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

Original poster: "Kurt Schraner by way of Terry Fritz <twftesla-at-qwest-dot-net>" <k.schraner-at-datacomm.ch>

Greg -

my coil "Black & White" is about the same as your coil project. My
wire is 1.27mm diameter (~awg16) , and I'm using a space between turns
of 0.84mm. Apart from the reasons John Freau already mentioned, I was
feeling the resonant frequency going too low, when close-wound. This
might lead to too big primary and tank cap. The yet continuing thread
about "Mutual Inductance & K Factor" of Bart Anderson and John
Couture, was also taking this TC as an example. You might like to have
a look at the construction and operation of this coil:

http://home.datacomm.ch/k.schraner/index.htm
look for B&W under "Equipment" and "Sparks".

The Excel design calculations can also be had under:
http://home.datacomm.ch/k.schraner/tc-plan.zip

While the behavior and appearence of the coil is quite satisfactory to
me, when winding it again, i would probably take PVC insulated wire,
which gives automatic space winding and good insulation at the same
time, with less of a hassle creating the space and sealing the coil
(Wouldn't bother about Q because of the PVC). I'm aware of at least 2
"brother coils" of my one, in Europe: Marco Denicolai's "Thor" and
Jens Raake's TC.

Cheers,
        Kurt Schraner


Tesla list wrote:
> 
> Original poster: "Mr Gregory Peters by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <s371034-at-student.uq.edu.au>
> 
> Hello all,
> 
> Today I scored some free 400mm (16") diameter PVC piping. Although this
> would make a coil much bigger than my current power supply is capable of
> feeding, it seems a shame not to use it (it isn't cheap), and besides, I
> hope to soon have access to 25kVA ability. So I have decided to make a
> new coil. I want to wind it with about 1.2mm wire (about 17 gauge). I'm
> wondering if a coil this big should be space wound? Richard Hull says in
> the CSN guide that space winding is not really needed for coils smaller
> than 20" diameter, provided a big terminal capacity is used to offset
> the distributed capacitance of the secondary? Any suggestions?
> 
> Greg Peters
> Department of Earth Sciences,
> University of Queensland, Australia
> Phone: 0402 841 677
> http://www.geocities-dot-com/gregjpeters