Re: The MTSG Metlicka Triggered Gap... (fwd)

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---------- Forwarded message ----------
Date: Mon, 14 May 2007 18:51:31 -0700
From: Barton B. Anderson <bartb@xxxxxxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: The MTSG Metlicka Triggered Gap... (fwd)

Hi Brett,


>I remember that exact picture of that gap you built. 
>I thought the large diameter tungsten were quite
>impressive.  I wouldn't say it was dumb gap, just
>might not have had the best heat sinking ability. 
>  
>
Yep, that was the dumb part. But, it's one of many such goofy gaps I've 
tried.

>By the way, what power levels were you running in that
>photo?
>  
>
Somewhere between 1500 to 1700 VA.

>I wonder if there is a "sweet spot" (low enough input
>VA) where the MTSG (as described in the Rosenburg pdf)
>can achieve a first notch quench...or at least one
>sufficient to allow sparks close to what one would get
>using a well designed SRSG?
>
I think with all Tesla Coil Systems, regardless of drive, there is 
always a sweet spot. It's not always achieved due to system components. 
I'm sure the same is true for the TSG. I'm not convinced it can do 
better than an SRSG simply due to the mechanical and thermal 
qualifications of RSG's.

>I suppose for single 12/30 or 12/60 systems, the MTSG
>would probably be a good idea for folks who might not
>have the shop equipment to modify an armature for sync
>use, or to properly balance and drill a rotor.  
>  
>
Absolutely agree. If a rotary gap is just not your bag of tricks, I 
think a trigger spark gap may be a great alternative. But, if your going 
to really run some power, an RSG of some nature is best.

>I have a friend who is considering construction of a
>MTSG, as an upgrade to his static gap.  He is running
>a single 12/60 NST.  I just thought I would ask around
>and get an update, plus I was curious about why that
>design just seemed to fall out of favor.  You and John
>have provided a lot of things to think about.
>  
>
I think your friend should build one. A 12/60 is a perfect sized tranny 
for a TSG. That is certainly in the realm of the TSG's power. I would 
recommend he build a large pipe gap (1.25" x 4" piping) for the 
electrodes. The thermal dissipation is excellent with a decent fan and 
can handle a 12/60 very well for maximum spark output. I no longer 
endorse the small copper tubing (it just sucks compared to larger tubing 
and thermal dissipation is why). I know I'm nobody, just a garage coiler 
like many here, but if I were somebody, that is what I would recommend 
from my experience.

I once built a large copper tube gap like this that sucked. The reason 
was airflow. Once I got the airflow high enough, good things happened 
from that point. That's what I like about RSG's, they are spun through 
the air at high velocity, and a fan is unnecessary. It always comes down 
to thermal stability.

BTW, one of my really goofy gaps was a spinning pipe gap. It was sort of 
a rotary, however I spun 1/2" copper pipe for the electrodes (you have 
to imagine 6" pipe lengths between 2 discs which were spun by a motor). 
Two stationary electrodes were gapped to a single pipe section. Sounds 
cool eh? Nope, it sucked. The carbon really built up where the 
electrodes fired and played havoc with the gap. I immediately replaced 
it with a G10/tungsten gap and the results were much (much) better. BTW, 
that type of goofy gap was a nightmare to build. See, I really have 
built some dumb gaps. Hey, but I keep trying new things. Knowing now 
what I didn't know then, would have saved me some blisters. But, we have 
to try new ideas. You never to old to try something different than the norm.

Take care,
Bart