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Twin coils was Re: Stand construction



Original poster: "Mike Novak by way of Terry Fritz <twftesla-at-qwest-dot-net>" <acmnovak-at-msn-dot-com>

Base sketches on the way...

> I am working now on a twin coil that has evolved from my 48 inch bipolar.
> Each resonator is 24 inches of # 28 on a 4.5 inch OD form. The topload is
> 4 x 17 heater duct. The primary coils are each 8 turns of 3/16 copper. The
> power input is
> 2.25 KW and Cp is 0.039 uF. I can get 60 inch sparks but I want more for
the
> 2.25 Kw
> I'm pouring into the beast. I managed a 65 inch spark just before the fire
and
> the 30 amp fuse blew.  :-))
>
> I am finding the tuning of the twin resonators kinda tricky. I would like
to
> learn about your twin, and especially any info on how you tuned the twin
> resonators.

My coils aren't exactly bipolar, they're just out of phase regular coils.
They're based on John Freau's TT-42 with a few modifications...

Tank caps are MMCs- 12 (series) x 2 (parallel) .1µF 3000vdc GE snubbers for
~16.6nF -at- 36kVdc. I've been told they're good for up to 15A RMS RF.

  Secondaries are 4.5" x 23" wound with 28 guage double formvar coated with
two coats of epoxy. Inside are an upper and lower baffle to prevent
flashover inside. They're topped off with a ~ 6" x 2" copper pseudo-torriods
and a 4" x 12" Al dryer duct torroid.

Primaries are ~19 turns of .165" wire (6 guage i think) on 120 degree UHMWPE
supports.

SRSGs are 3600RPM -at- 120 BPS with copper electrodes backed by a safety gap.

Power is supplied by two OBITs on each unit (recommended but not supplied
for liability reasons).

Coils and motors draw  ~ 12 amps peak. I tuned them seperately, same as any
other system.