Re: Mini VTTC--Possible tubes?

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

Original poster: "David Sharpe by way of Terry Fritz <twftesla-at-qwest-dot-net>" <sccr4us-at-erols-dot-com>

Matt, Carl, All

Another excellent mini-VTTC tube is an 807 (6.3VAC fils) or 1625 (12.6VAC
fils).
Use in same sweep tube circuit previously mentioned.  Plate P ~ 30W, Vbb +750V
Vsg +300V.  One tube single ended about 90W out, 2 in push-pull will net about
100W.  Actually successfully ran 6 807WA (ruggedized 807) as 3 in parallel x 2
banks push pull at 800V.  600W input, about 450-500W to resonator to drive
a IR laser tube (yes it worked by at <10micron pressures  :^?)  got on a video
around here somewhere...  About 1 1/2" - 2" plasma torch style discharge
(lot of
heat!!!)

Regards
Dave Sharpe, TCBOR
Chesterfield, VA. USA

Tesla list wrote:

> Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<cwillis-at-guilford.edu>
>
> Matt,
>
> Any of the "sweep" tubes from televisions are useful for the very smallest
> tube coils.  Mark Reszotarsky (sp?) has a schematic on pupman-dot-com for one
> such beam-tube tesla coil.  My website at
> www.angelfire-dot-com/electronic/cwillis also details such a tesla coil, using
> a minimum of parts, in the context of a "plasma tweeter."  You won't get
> much spark out of these little coils, but they are very cheap to build-
> they even lack a traditional primary tank circuit, and you end up needing
> only a source of plate voltage, filament power, a small RF choke, a small
> "secondary" coil, and a grid-bias resistor.
>
> The 811-a triode is a good starting point for many builders.  They used to
> be available for $10 from RFparts-dot-com, but I think the prices have gone up
> a bit.
>
> Essentially any glass triode makes a good tube to start with.  More grids
> means you have to figure out a little more, and they can be a nuissance to
> deal with.  Glass tubes are recommended over ceramic ones, in my opinion.
> For one thing, the sockets are easier to come by.  I have two medium-sized
> glass triodes on eBay right now, item 1710445087.  They have no number but
> are ideal for tube coils since I have used them for that purpose.  It
> shouldn't be hard to find a plethora of potentially great tubes.
>
> Good luck.
>
> Carl Willis