Original poster: "Barton B. Anderson" <bartb@xxxxxxxxxxxxxxxx>I'm showing 13.2 turns with Javatc. But as is safe and always a good idea, more turns are smarter than not enough. A 16 turn primary would be a good place to start (then tune to 13.2 turns - grin!). 30" sparks are possible when "the planets align". Expect something less. You mentioned over a foot of sparks. Certainly that is reasonable and probably true during those first light runs. It is possible to hit 30", but anything less than that can be contributed to spark gap losses. On start up of a new coil and coiler for that matter, the spark gap is an area that will improve a coils spark length performance a great deal. It does take experience to get a feel of what works and what doesn't, how much air flow is enough and how much is too much (and why no air flow is almost always a bad idea). Once the coil is up and running, take a look at whatever your using and check out what others have done who get good performance. Do what they did and improve on their gaps if possible.
Take care, Bart Tesla list wrote:
Original poster: Slurp812 <slurp812@xxxxxxxxx>Iv been doing some primary/secondary calculations with both programs, and all else being equal (at least I think so) WinTesla shows 14.7 turns for the primary, and TeslaMap shows 10-11 turns. I am assuming that this is typical as there are so many varaibles in actual construction that can change the resonant frequency. anyway, heres what I am working on so far:15/30 NST ~9nf cap 3.5 inch OD pvc for the seconday coilform 17 inches of 28awg magnet wire ~1135 feet, ~1239 turns 12 gauge (.064mm) bare copper wire for the primary (yes its small) 5.5 inch inner diamater .2 inch spacing~10 inch diameter sphere for topload (thats what I am using for calculations so far)I am hoping for 1 foot or better streamers, does that sound resonable?