Re: VTTC output

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

Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>" <FutureT-at-aol-dot-com>

In a message dated 2/13/01 9:13:10 AM Eastern Standard Time, tesla-at-pupman-dot-com 
writes:

> 
>  The brush is about 15"long and very intensive blue, starting from a 
>  horizontal piece of rectangular aluminum sheet atop the toroid. 
>  Reason: The toroid is made from foam and covered with aluminum 
>  foil. Using a small discharge pin caused overheating and burned 
>  the toroid. I'd better made it from copper tube!
>  
>  Could I expect more output? At present primary (about AWG 15) 
>  and secondary (about AWG 26) barely get warm. Much space for 
>  improvements?!?
>  
>  Any advice is appretiated very much.
>  
>  Herwig

Herwig,

I just judge by the spark length, and adjust the circuit for minimum
tube redness at a given spark length, and minimum input power.
It's very hard to get long sparks with filtered DC (takes a lot of power).
I got 7" sparks using filtered DC on my small coil, but I couldn't keep
it on too long, the 4-250A tube got too hot.  But my coil was optimized
for AC operation.   Your tube should handle
4 times the power (as mine), and your spark length is twice as long.... 
seems about right to me.  Tube coils may benefit from using a thicker
wire for the primary and secondary, because of the way they are pumped
up by the oscillations (Q pumping).  I haven't done much experimentation
in that area though....  but I plan to.  

John