Re: New VTTC (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Sun, 05 Aug 2007 23:00:40 -0400
From: David Speck <dave@xxxxxxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: New VTTC (fwd)

Matt,

I asked a similar question a few years back -- was there an intrinsic 
limit to the size and scale of a VTTC?  It seems like about the biggest 
VTTC I've seen has a roughly 4" secondary, driven by 1 to 4 833s, with a 
max spark length of perhaps 30", roughly corresponding to a 12 kV 30 mA 
NST system.  OTOH, disruptive coils have grown to the megascale of the 
LOD setup with hundred(s) of kW inputs. 

It seems like there are lotsa really big power tubes out there, like a 
3CX25000, or the 5 kW industrial glass bottles I scored from an old 
induction heating system which just cry out for a 12" or 24" secondary 
to drive, yet, I've seen no one build something of this scale.  

Cameron Prince  did some innovative work recently by which he was able 
to get much better discharges from a single 833 by moving the feedback 
coil nearly half way up the secondary.  Not sure why it worked, but I 
have one of his coils that can do at least 24" discharges in staccato 
mode with a single 833A driven by two MOTs, with the plate just barely 
getting red. 

I didn't get any definitive responses last time.  It sure would be 
interesting to see if a large scale VTTC could be developed. 

Dave


> Has anyone tried designing an optimal VTTC based on the tubes  
> characteristics and design parameters or is that a long dead art, and now  it's all mimic, 
> cut & try, and anything that doesn't blow up or melt is good  enough? Maybe I 
> missed something, but I have not seen any references to theory  or design 
> applied to the oscillator, like the detailed theory and  design applied to the coil 
> itself. (javatc etc.)
>  
> Any old-timers know what I'm talking about?
>  
> Matt D.