Re: tesla's colorado lab

[FutureT-at-aol-dot-com (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

In a message dated 8/10/00 11:50:38 AM Pacific Daylight Time, 
tesla-at-pupman-dot-com writes:

> Also, Tesla once
>  said "...the builder will find that hundreds of turns are not necessary 
for 
> the
>  secondary to achive high voltages..." This was quite a shock to me seeing 
as
>  most of use use upwards of 800 turns on our coils. I realize that he was
>  talking about magnifiers, but can't we apply this knowledge to our coils? 

Michael,

If the form is very wide, then it can have fewer turns and still have
a lot of inductance.  Skip Greiner used this method and got good
sparks from a NST with a sync gap.  Skip used about 270 turns
I think on a 17" dia form. He used 16awg machine tool wire with
a thick rubber insulation.  It would have been interesting to 
compare his results with that of a more traditional secondary and
primary.

>  Anyone tried using really large wire on their secondary? 

The thing that concerns me using thick wire is that the inductance
may be somewhat low, and also, the wide form needed to get a large
inductance may overwhelm the toroid, unless a huge toroid is used.
But a huge toroid will demand more power and kill the "efficiency"
in that way.  I wish folks would do a lot more experimentation in this
area though, because it is all interesting and deserves some good
comparison experiments.

>  I'd like to try a 4" x 16" (10cm x 40cm) coil wound with 18 guage enameled
>  wire... That might be interesting along with a tightly coupled primary with
>  maybe two or three turns of 3/8" copper tubing. 

I did a comparison of a 6.5" by 24" secondary wound with 28awg
wire which gave 42" sparks.  I compared it with a secondary (actually
the same secondary which I rewound) wound with 20awg wire.  My
sparks were reduced by 10%, and the sparks were much weaker
looking, and less dramatic.  I kept everything the same except
for the primary which was needed to tune the different secondary
setups:  Using the 28awg secondary, I used 20 turns of 12awg
close wound wire for the primary.  Using the 20awg secondary,
I used 10 turns of 1/4" copper tubing.  I varied the coupling for
best results in both cases.

John Freau


>  Any thoughts?
>   
>   
>      -Michael 
>