NST Life Expectancy

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

Original poster: "WIZZARD . by way of Terry Fritz <teslalist-at-qwest-dot-net>" <pbobyk-at-hotmail-dot-com>

My 4" coil and had one of the NST's die.
I suspect my protection circuit was the cause.
I made a Terry filter and put it on my remaining NST.
I believe the second transformer has now failed.
I'm new to this game but I think a transformer should last more than a 
couple minutes of operation.
What is the normal life expectancy of an NST?

The second 15KV/30mA transformer was doing great. The coil was tuned and my 
new RQ gaps were opened full..
I could hear some internal arcing inside the NST case and could smell a 
burning smell.
I pulled the top off the transformer immediately and some smoke/steam came 
out as I lifted the cover.
I could see the tar had cracks just like the last one that failed. This 
time there was a small hole where what looked like water had condensed 
around. The liquid was also condensed on the top that I lifted off. The 
transformer case was quite warm if you grabbed the case.
What is happening?
How can I stop this.

A quickly going broke coiler... LOL!

_