833 coil

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

Original poster: "John Richardson" <jprich-at-up-dot-net> 

Hi,

I recently acquired an 833a tube, and would like to proceed with making a
coil.  The only requirement that I want to impose on this project is
longetivity, even at the expense of spark length.  The goal is to be able to
run for extended periods without worrying about tube damage, allowing for
various experimentation.

Due to time constraints, I am hoping plagiarize a working, single tube
design.  After I have an operational coil, I can then proceed to alter
parameters to notice their effect.  Also, due to a relative lack of
knowledge with electronics, I believe that going with an existing design
will allow for a better learning experience than continuously fiddling with
component values that I know nothing about.  Here goes:

1)  10v 10A filament transformers seem impossible to find.  Would I be able
to use the trans out of a 12 volt battery charger and throttle it back with
a variac?  Or, would it be better to use a MOT with the secondary removed
and wind a few turns of wire on it like everyone else has done?

2)  Plate transformers designed to feed an 833 are super expensive and
heavy.  MOTs again?

3)  Does anyone have a link with a solid, simple one tube design that they
would be willing to share?  It's my understanding that a lot of the
component values aren't critical, but since I'm the type of person who has
to be hands on to learn, they would assist me in getting together a project
where results can be seen.

4)  I have gone thru the archives and done lots of reading on other's
projects to alleviate you guys from reiterating what has been said many
times, as well as making countless visits to Steve W's, John F's, and others
websites.  I've read the tube section of my old AARL Handbooks many times as
well, and am getting an understanding on the tube process.  However,
assembling a project that I know will perform seems to help ease the mental
anguish and promote an understanding of what I am doing.

5)  I've got two of John F's small toroids (2 by 6?).  Will I need something
bigger?

6)  I have to ask:  How much spark can I expect with a durable design?

Thanks for any info,

John Richardson