The coils shown below are all tuned by their constructors to what they feel is the best tuning. We then model each setup in some detail, to examine the tuning of the coil, and to compare the available topload charge and field strengths with the observed breakout characteristics.

System	Name	mm3p	jftt42a	jftt42b	mw1	ba0
	Diagram (not to scale)
Secondary	Length (meas)	40.54"	18.75"	18.75"	47.0"	39.75"
	Diameter (meas)	8.712"	4.2"	4.2"	9.9"	8.438"
	Base height (meas)	14.0"	20.31"	20.31"	10.0"	28.938"
	Turns (meas)	2989	1307	1307	980	1789
	Ldc (calc)	383.5 mH	36.6 mH	36.6 mH	46.0 mH	131.4 mH
	Ldc (meas)		36.7 mH (+0.3%)	36.7 mH (+0.3%)		131.1 mH (-0.2%)
	Rdc (calc)	425.8 ohms	94.7 ohms	94.7 ohms	55.0 ohms	103.0 ohms
	Rdc (meas)					99.8 ohms (-3.1%)
Primary	Diameter (meas)	12.25"/34.75"	6.25"/12.5"	6.25"/12.5"	26.0"	11.1"/32.875"
	Height (meas)	14.0"	19.685"	19.685"	10.0"/14.0"	28.75"
	Tap/Turns (meas)	23.95/25	14.5/18.5	16.5/18.5	4/4	13.5/15.3
	Lpri (calc)	356.6 uH	63.0 uH	81.3 uH	18.3 uH	102.1 uH
	Lpri (meas)		58.2 uH	75.1 uH		102.0 uH
Input	Firing voltage (meas)	33.9 kV	26.599 kV	26.599 kV	8 kV	22.3 kV
	Cpri (meas)	52 nF	14.7 nF	14.7 nF	0.1 uF	65.39 nF
	Bang energy (meas)	29.88 J	5.2 J	5.2 J	3.2 J	16.26 J
Topload	Geometry (meas)	Toroid 30.5"x6.5"	Toroid 13"x4"	Toroid 24"x6"	Spheroid 24"x10.5"	Toroid 30"x9"
	Height (meas)	58.54"	42.661"	42.661"	63"	77"
	Specific gradient (calc)	0.052 V/cm/V	0.100 V/cm/V	0.068 V/cm/V	0.056 V/cm/V	0.044 V/cm/V
Resonator	Cee (calc)	44.7 pF	17.6 pF	31.9 pF	33.5 pF	39.5 pF
	MCTV (calc)	1156 kV	769 kV	571 kV	437 kV	907 kV
	Surface field at MCTV (calc)	60.1 kV/cm	76.9 kV/cm	38.8 kV/cm	24.5 kV/cm	39.9 kV/cm
Tuning	Fpri (calc)	37.0 kHz	165.4 kHz	145.6 kHz	117.7 kHz	61.6 kHz
	Fpri (meas)					61.6 kHz (+0.0%)
	Fsec (calc)	38.4 kHz	198.3 kHz	146.9 kHz	127.8 kHz	69.6 kHz
	Fsec (meas)		196.0 kHz (-1.1%)	147.0 kHz (+0.1%)		69.7 kHz (+0.2%)
	Primary offset (calc)	-3.7%	-16.6%	-0.9%	-7.9%	-11.5%
Response	Vtop (calc)	1011 kV	414 kV	517 kV	254 kV	601 kV
	Surface field (calc)	52.6 kV/cm	41.4 kV/cm	35.2 kV/cm	14.2 kV/cm	26.4 kV/cm
	Charge surplus	15.2 uC	2.1 uC	3.8 uC	-4.7 uC	0.3 uC
	Streamer-feet	30.5 feet	8.0 feet	10.0 feet		0.5 feet
	Appendix	Waveforms Animation Surface Gradients Modes	Waveforms Animation Surface Gradients Modes	Waveforms Animation Surface Gradients Modes	Waveforms Animation Surface Gradients Modes	Waveforms Animation Surface Gradients Modes
Breakout	Streamers	Multiple 80-90".	Tuned so that the sparks barely break out, 2 or 3 simultaneous streamers, If tuned for a higher frequency, then there are more streamers, but they are all shorter.	Seems to be right at the edge of breakout. There was only one streamer.	None without breakout point.	1 or 2 streamers at a time.
	Racing arcs	Never seen racing arcs on this coil.	Very close to creating racing sparks, but never appear.	No racing sparks.	Never.	No racings arcs.

Some terms and definitions:

MCTV: Maximum Conceivable Top Volts - based on the estimated bang size and the calculated energy storage capacitance of the resonator, and assuming perfect tuning and no losses.

Surface field: The highest E-field stress occuring on the surface of the topload.

Specific gradient: The surface field of the topload when at a potential of 1 volt.

Charge surplus: The excess charge in the topload, over and above that required to lift the potential to the point of breakout. This represents the surplus charge available to form streamers. A negative value is the amount of topload charge by which the system falls short of breakout.

Streamer-feet This is the average streamer length multiplied by the number of streamers, in other words the total combined length of all streamers. Calculated by assuming that all the surplus charge is transferred to streamers at 1pF per foot.

This is very much a work in progress. Only the coil model BA0 is sufficiently qualified by measurement cross-checks to be relied upon, but there is a suggestion of a trend towards negative tunings, which is the expected behaviour. Hopefully the picture should become clearer as more measurements come in.