Re: Coil questions

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

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


Original poster: "Corey May by way of Terry Fritz <twftesla-at-uswest-dot-net>" <
cbmay-at-home-dot-com> 

Hi Corey! 

These are my preferences. 

<Hello, I have just a few question I would like to ask you. Is plexy glass or 
cutting board material a good substance to used as primary supports and to as 
and end cap on the secondary?> 

      I have found that both Plexiglas and the white polyethylene "cutting 
board" material are electrically good. However, the Plexiglas, Optix, Lucite, 
etc., acrylic types are more prone to cracking, chipping, and splitting when 
being cut, drilled, etc. HDPE is far more forgiving, so unless you are very 
careful or the sex-appeal of clear plastic is overwhelming, I'd say use the 
"white stuff". 

<What is the best wire guage to used with a 15kv, 
120ma trany.....does 22 sound right? > 

   Assuming you mean secondary winding wire, the ideal wire size is still a 
matter of some debate. I have a 1.875" coil wound with 800T of #28 which runs 
well on a 10/23 OBIT and a 4.5" with 820T of #23 for use with a 15/60 NST. 
Most of the coils I've seen under 5 KVA use #20 to #30 wire, so #22 is in the 
ballpark. For other on-board wiring, I like #8 to #12 run through clear 
plastic aquarium air hoses for good measure. 

<What is the best spacing to use between 
the secondary and the Primary?> 

     For any HV spacing, I like dv/ds= 20 kV/inch or lower. Since, for a 
15KV ungrounded primary, dv(peak) is 21.2 kV, an inch minimum would be my 
recommendation for flat or cone primary and significantly more (2X - 3X) for 
a helix. 

<And Finnaly what is the maximun shunt plates you 
can take out of an NST with out killing it or putting it under so much stress 
that it fries within an hour or so of non continous use?> 


     I am no expert on shunt removal, so I'll let others advise you on the 
details. It seems to depend on 1) the geometry of the specific transformer, 
2) the number you started with, and 3) the amount of brass in the orbs of the 
coiler. The "Microsoft answer"(Completely Accurate but Totally Useless) would 
be: one less than smoked your last tranny of the same size. :^ )) 

Wound up, 

Matt D.