Original poster: "Gerry Reynolds" <gerryreynolds@xxxxxxxxxxxxx> Hi JT,An alternative is to input your design into one of the several very good tools available. I use JAVATC (Bart Anderson's program). This will give some very useful info including the top load voltage (ideal equation I believe which is half the story). Next, you could use the INCA (Antonio's) program that will do field plots and figure out your toroid breakout voltage. Take the lesser of the two as the top load voltage. For this purpose, you can calculate the bang energy (0.5*C*V*V) and use this assuming no energy loss to calculate the peak current in the primary, peak voltage in the secondary, peak current in the secondary and get the ideal values for your coil. Energy in an inductor is 0.5*L*I*I. Remember that energy swaps back and forth between the capacitor and inductor in a LC resonant circuit. You can get the inductance of your primary and the equivalent energy inductance (Lee) and equivalent energy capacitance (Cee) of the secondary from JAVATC. You could use a derating factor of 0.7 if you like to account for losses in the spark gap. This is probably the best you can do short of some sophisticated measurements.
If you want to measure the topload voltage, you can make a plane wave antenna (Terry's design and he has info on this at hot-streamer.com) and use a scope. Or, you could use Dr Resonance procedure using the single bang spark length distance.
Humidity will affect the Q of your secondary by increasing the dialectric loss. Sounds like you know your BPS and if you can get your hands on a HV probe with scope, you can measure the bang voltage. Please be safe when doing this.
To improve your design, I would first get some good polypropylene capacitors for your primary and build a MMC capacitor with value of 1.6*Cres for your NST. Cres for a 12KV 30ma NST is 6.6nf, so I would build a 10.6 nf MMC with a total voltage of at least 20KV. Make the toroid size as large as possible without its breakout voltage exceeding the voltage the coil will produce with that size toroid.
Gerry R.
Original poster: "JT Bowles" <jasotb@xxxxxxxxxxx> I need to know, for sure, what my coil produces.(voltage & current)I can tell you all humidity, spark distance, breakrate of topload, and resonant frequency of secondary, and much more.* currently its about 70% humidity * my topload breaks out at 210 Hz * unloaded secondary is 240KHz * maximum spark distance is 15.5 inches * topload is 10.5 inch diameter toroid, 3.5 inches thick * topload is semi-smooth Aluminum air ducting w/ foil tape all over it * no clue about output currentcan you tell me, with this informartion what the output voltage is? Current would be nice too, but il need to measure that one somehow.Borne coiler, JT Bowles