Re: 6146A Vacuum Tube Tesla Coil Questions

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

Original poster: Mddeming-at-aol-dot-com 

In a message dated 10/25/03 9:12:30 PM Eastern Daylight Time, 
tesla-at-pupman-dot-com writes:
Original poster: "Enrique Muyshondt" <Endeavour-at-austin.rr-dot-com>

Hello,

I'm working on making a Tesla Coil using a 6146A Vacuum Tube using
schematics
(<http://www.pupman-dot-com/msrp/tesla_vacuum.jpg>http://www.pupman-dot-com/msrp/tesla_vacuum.jpg) 

by Mark S. Rzeszotarski, Ph.D. and was hoping that someone here could lend
me a hand in acquiring some of the parts.

I initially wanted to build a coil using two 833A tubes, but when they run
at 130 dollars each, that was more than I wanted to spend.

Anyway, I sit here with this schematic, and I am trying to locate all the
parts. I have already acquired the 6146A tube, but I need a Variac, or 120
to 600 VAC non-variable transformer - either will work, whichever is
cheapest. I also need a source for the 1 inch brass sphere on the top of
the coil, and that white ceramic piece that goes under it.

I am pretty sure that I can get all the capacitors and resistors online or
locally.

What do the 'K' values in the schematic represent?

If you have any sources on the above, or for anything in the schematic
(minus the tubes) I'd appreciate it if you could let me know. General
tricks and tips appreciated as well.

Thanks!

-Enrique

Hi Enrique,

     The brass ball can be purchased on line or at most lamp stores as a 
"1-inch brass finial". It's the thing on the top of the lamp that holds the 
shade on. Solid brass can be had for <$10.00 USD. These come with a 
threaded hole but sometimes they have an odd thread size like 27 TPI, so 
it's a good idea to get the threaded rod from the same store or you may 
have to rethread the ball to a more standard size. Solid brass doorknobs or 
drawer-pulls are harder to come by and usually cost more.
  Ceramic stand-off insulators can be purchased on eBay. the exact shape 
and size is not critical as long as it's something close.
You will need both the 0-120V Variac and the 120V to 600V power supply 
transformer. That size Variac is frequently available on eBay for ~$10.00 
or less, and power transformer is usually ~$15.00 used to $30.00 new, but 
they are heavy 10-20 lbs, so shipping might be expensive. Many of these 
come with a built-in 6.3V filament winding, but you cannot use it because 
you need control on the primary side of the power transformer while the 
filament stays at 6.3V. Ham radio swap meets are the best places to find 
these.
The "K" values are the coupling coefficients between the coils that will 
exist if you build according to the plan dimensions. You don't need to 
worry about them right now if you stick with the dimensions given.

Hope this helps.
Matt D.