Re: feedback on my coil please

["Barton B. Anderson" <tesla123-at-pacbell-dot-net> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Hi Pholp, 

Tesla list wrote: 

>
> Original poster: "Pholp Smiff" <kawanze-at-hotmail-dot-com> 
>
> Im nearing completion of my first coil, and would like to run the specs by 
> everyone (or anyone). 
>
> (2) 12kv-at-30ma trannies paralleled. 
>
> .0132 mF or somewhere around there (got them off ebay for dirt cheap while 
> everyone else was telling me it wasn't possible : p) 
>
> now here's where there might be problems, with my spark gap: 
>    i went to good ole home depot and bought a piece of quarter inch 
>    acrylic and got copper piping (1") and cut it into 6 
>    pieces and arranged them zigzagged. I ran 12kv-at-90ma through it        to 
> see how fast it got hot, and it did pretty well, got warm after    about 2 
> minutes ( at least i think that's good): 
>    ------------ 
>     O  O  O           <- don't laugh 
>       O  O  O 
>    ------------ 
>    i built it so i can adjust it a bit also. 
>
> my primary is .25" copper refrig tubing, flat pancake 22" diameter (whole 
> thing) 
>
> secondary is 28 inches long, 4.5" OD wound (30 inches tall total) 26 
> guage magnet wire (i stopped by terry's page and saw his 1600 wound   coil 
> and his results so...) my coil is probably 1500-1700 winds. The   only 
> problem with this is i coated it with shellac instead of    copper  wire (it 
> won't cover like one strand in the coil) will  this   be a problem? it's 
> only tiny tiny areas. 
>
> my torroid: aluminum dryer duct: 22" OD the design program i used said 
>   that it would need to be around 30 inches, but i don't want my coil 
>   to look stupid, so i made it a bit smaller. Is there any way i could 
>   make up for the difference in required capacitance? could i add 
> another toroid or a hemisphere on top or something? 
>
> thanks 
>  


Your design sounds fine. I dont' understand the shelack problem. Shelack should
be fine. You can add a second toroid to increase capacitance. I would just go
with what you have now and go from there. You could achieve around 46 inch
sparks with this design if the top load is optimized. You have a good number of
turns on the primary which should help to achieve this. 

Bart