Re: Primary coil design

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

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Parpp807-at-aol-dot-com>

In a message dated 5/31/02 9:46:40 PM Central Daylight Time, tesla-at-pupman-dot-com 
writes:

> altho it does present some difficulties in tuning, 
>  secondary spark racing, and in general ...   supportive structures which 
>  lend to an non-easy design to produce.

Hi Scot,

Au contraire.
Take a look at my pictures of the helical coil primary for my 4.5 x 24 inch 
with the 28 inch toroid. Yes, the solenoid does couple tightly and sharply. 
>From way undercoupled to
optimum to racing fireworks can take place within an inch of adjustment. 
Tuning also seem sharp. But the physical design is not only easy, but I think 
it is easier to adjust 
the coupling for the solenoid than it would be for the Archimedes spirals I 
have seen.
Let it be known that I have never made an Archimedes primary, but making the 
helix
and adjusting the coupling is easy. See the pictures for just one method of 
supporting the helix. What you see is all done with scrap PVC. To support the 
secondary you mount a toilet flange onto a piece of 3/4 plywood and use a 
length of schedule 40 PVC of a size that will telescope in and out of the 
secondary like a sliding trombone. That's it.
That's all that is necessary. My secondary is wound on 4.5 OD schedule 40. It 
telescopes
over a length of 3 inch schedule 40. The schedule 40 is important for the 
thickness of the walls. The pictures show the 3/8 x 16 nylon bolts at the 
bottom of the secondary that screw
thru the tapped holes to hold onto the inner tube. Very easy to adjust, and 
IMHO, better than anything I have seen for the Archimedes primary.

Happy day,
Ralph Zekelman