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Re: NST insulations

At 03:32 PM 03/04/2000 -0500, you wrote:
>Hi All,
>    I'm trying to enhance one of my 15/60 Jefferson NSts. Hopefully i can get 
>200ma, but before i get there, I must overcome arcing problems. Right now 
>while i cut off shunts(these da#-at- Jefferson's don't have those 
>"remove-a-shunts" and i need to cut them) it runs dry for testing to make 
>sure it'll run. I usually run it dry for about 3-4 secs -at- 75% power on my 
>variac. After i push up the power, i get an arcing from my Secondary to my 
>core. Of course i turn it off here. What i want to know is if there is 
>anything temporary that i can use to prevent arcing during my testing? When 
>i'm done w/ the de-shunting process, I plan on potting the nst back in 
>vaseline. Is there anything bad w/ using Vaseline? I also have about 5 
>gallons of mineral oil i can use to re-pot, but that is really really messy 
>and i want to avoid that.
>Stumped!
>-Alan
>

Hi Alan,

	You can simply run the NST through an ammeter which looks like a short to
the NST.  Thus, the voltage will be almost zero preventing arcing while you
adjust the shunts.  I have a simple ammeter plan below if you don't want to
risk a nice DMM.  If you do use a DMM, I would suggest removing the fuse
and replacing it will a fuse wrapped with aluminum foil.  If the fuse
blows, the meter will fry so you have to be sure it does not blow.  Be very
careful to hook the DMM up properly the FIRST time because there will not
be a second time...  Remove the foil when you test is done ;-)

http://www.peakpeak-dot-com/~terryf/tesla/misc/meter.jpg

You should be able to run the NST at full power and see the short circuit
current.  For 200mA, you will want two 1000 ohms resistors and double the
scale reading in my meter above.  200mA is a lot of current for a 15/60 but
to each their own...  The core may saturate before you get there...

Cheers,

	Terry