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Re: poor performance
From: Bert Hickman[SMTP:bert.hickman-at-aquila-dot-com]
Reply To: bert.hickman-at-aquila-dot-com
Sent: Sunday, November 30, 1997 12:35 AM
To: Tesla List
Subject: Re: poor performance
Tesla List wrote:
>
> From: kevin[SMTP:wawa-at-spectra-dot-net]
> Sent: Saturday, November 29, 1997 4:49 PM
> To: Tesla List
> Subject: Re: poor performance
>
> Tesla List wrote:
> >
> > From: Bert Hickman[SMTP:bert.hickman-at-aquila-dot-com]
> > Reply To: bert.hickman-at-aquila-dot-com
> > Sent: Friday, November 28, 1997 9:54 PM
> > To: Tesla List
> > Subject: Re: poor performance
>
> (SNIP)
>
> > Could you have you added too much capacitance for the current rating of
> > your transformer? What size transformer do you have and how much
> > capacitance are you loading it with? Regarding your cap question - all
> > things being otherwise the same (i.e., the same active plate area and
> > dielectric thicknesses), the more tightly rolled cap will probably have
> > somewhat more capacitance since the plates will be pushed more tightly
> > to the dielectric.
> >
> > Safe coilin' to you!
> >
> > -- Bert --
>
> I have 2 9kV 30mA in parallel. I don't have a capacitance meter yet
> (it's on the way for christmas though!) but I had my bottle caps
> measured before and they were all pretty consistant. With my small 4"
> coil I was using aprx. .011MF. When I wanted to use my new 6" coil, I
> found that I needed to increase the number of turns on my primary so I
> decided to use some more caps (about 10) for a total of aprx. .019MF.
> It didn't work very well, and I had to turn up my variac even mofe
> before the spark gap would start doing it's thing. Seeing it wasn't
> workin, I just started to go backwards with little if any luck.
Kevin,
Two 9 KV 30 MA transformers can drive about 0.017 uF at 60 Hz... the use
of a 0.019 uF cap is a bit bigger than this, but will probably work OK.
You may want to drop the value a bit. Don't open the gap too widely,
since you're close to 60 Hz resonance between your tank cap and your
transformers. It sounds like you may be out of tune. With the main gap
reduced (to reduce power level), try putting a thumbtack, point upwards,
on top of the outer top surface of your toroid to force spark breakout.
Then try running at various primary tap settings until you get maximum
spark output. You can then begin increasing power levels by widening the
main gap.
Safe coilin' to you!
-- Bert --