[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: 833 coil



Original poster: "Steven Ward" <srward16-at-hotmail-dot-com> 

Notice that the Q of the coil overall will change drastically from using 1 
tube to using 2 tubes!  In order to truly optimize a single tube coil, you 
must redesign the tank parameters...likely using a higher impedance.  But, 
the spark lenght figures Dan mentions sound right on for the tube.  Also, 
Dan mentions the placement of the coil and spark lenght... this is all too 
true!  Any time i try to run the VTTC at a thon, its always dissapointing.
Im reworking the whole coil now though, so Dan better watch out!  But 32" 
is outstanding!  How is the tube redness at that level Dan?  And what 
staccato pulse rate?

Steve Ward


>From: "Tesla list" <tesla-at-pupman-dot-com>
>To: tesla-at-pupman-dot-com
>Subject: Re: 833 coil
>Date: Sat, 27 Sep 2003 09:10:26 -0600
>
>Original poster: dhmccauley-at-spacecatlighting-dot-com
>
>
>The John Freau design i am currently using works extremely well and is well
>documented on my page here:
>
>http://www.spacecatlighting-dot-com/teslacoil12.htm
>
>Although this design shows paralleled 833 tubes, the design would just about
>identical for a single, triple, quadruple, etc... 833 VTTC.  Just need to
>size your filament and plate
>transformer accordingly.  10V, 10A Filament transformers are actually
>readily available.  I'm not sure why everyone has a difficult time finding
>them.  www.newark-dot-com sells them as
>well as many other distributors.  The major filament transformer vendor now
>is Hammond MFG at www.hammondmfg-dot-com  If you go to the website, just look
>under distributors and place
>your order.  Even if the distributor does not list a specific transformer
>explicitly, doesn't mean it doesn't sell them.  I buy all my 10V, 10A
>filament transformers from www.newark-dot-com and usually
>get them within a day or two of placing my order.  They are about $28.00
>each.
>
>You really don't need a plate transformer.  A MOT will work great, although
>for much shorter durations than a properly rated plate transformer.  Also,
>you will want to build yourself a
>Stacatto controller (Cathode Pulser) to reduce the average power to the
>tubes, ESPECIALLY if you are only using one tube.  This way, you can still
>go for the maximum arc distance, maximize
>peak power to the coil, yet reduce average power.
>
>Those small toroids from John Freau will work just fine.  You really don't
>need a larger toroid as you really aren't building up total voltage on the
>toroid anyways as you typically always use
>a break-out point on top of the toroid anyways.  Most VTTCs i've seen use
>just a small disk as the topload.
>
>For a single 833A running with a stacatto controller, i think you could get
>about 12-15" no problem.  After a lot of work and tuning, you could probably
>increase length up to 20".
>My maximum spark length so far with my dual 833A coil is 32" which was done
>quite recentlly.  Its very sensitive to tuning and the only place i can
>successfully run it at those arc lengths
>is in my basement at my mom's house.  Everywhere else, performance is down
>to about 24-26".
>
>Dan
>
>
>
> > 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
> >
> >
> >
> >
> >