Re: Fully threaded coil forms; *extremely* powerful Oudin Resonator
Ahhhhh, The wonders of close coupling. My short fat close coupled 5 1/2" x
10" bi-polar TC (ungrounded centered primary) Exhibited the same phenomena
until a major arc from the primary burned nasty hole through the shellaced
cardboard coilform when I pushed it a little too hard. I've threaded
coilforms myself a few times but not in the fashon that you did with the
primary on the same form. .I'll have to fire up the 12" Grizzly lathe and
try it myself and see what happens. .
----- Original Message -----
From: Tesla List <tesla-at-pupman-dot-com>
Sent: Saturday, May 29, 1999 10:41 AM
Subject: Fully threaded coil forms; *extremely* powerful Oudin Resonator
> Original Poster: "Jeff Behary" <jeff_behary-at-hotmail-dot-com>
> I have tried a few things rather unheard of these days in regards to coil
> First, I threaded my coil form before I wound it...time consuming, but
> [12" Shelton Lathe: 3 passes to true OD (115 RPM), 2 passes of threading
> tool (30 RPM)]
> Second, I wound both primary and secondary coils on the same form,
> like an Oudin Resonator.
> Coil Form: 8.625" PVC, approx. 9" tall.
> Secondary: Approx. 172 turns, 30 AWG, wound into 6" of cut threads-- 28
> Approx. 1 1/2" of pipe, directly under secondary, last turn soldered
> directly to it.
> Primary: 6-8 turns of bare copper wire, wound into grooves cut at 6 TPI.
> To just run a quick test of the coil, I wired it up to a tiny 6kV 20mA
> transformer/condenser/stationary gap - the results were spectacular for
> a small bugger. I was sitting on the floor 2 foot away and instantly the
> hair stood up on my arms and legs from the effleuve- after switching off
> lights, the coil was even more immpressive on this 5 minute test...the
> entire surrounding air of the top of the coil was ionised, and in a
> untuned state sparks well over 6" of an enormous quantity were drawn off
> a chunk of aluminum bar stock.
> To briefly describe the effluve, branching brush discharges leaped out
> the top most wire about 5" in length, powerful ionisation of the air
> a grounded object [my arm] as far as 8-10"; with proper adjustment of
> gap it is likely a 12" fine grain effluve could be had.
> I was very surprised by the intensity of the sparks -- the discharge to
> ground consisted of many thick sparks, very powerful for the small tank
> It is very compact, and looks superb with some maple polyurethane.
> The pre-threaded form, "wire in grooves" is quite attractive...if not a
> Jeff Behary
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