Here is the medicine coil as it is stored. I don't run it here because there is no convenient R/F ground.
Here is the medicine coil as it is stored. I don't run it here because there is no convenient R/F ground.
When I run the coil, I use this configuration. Note that the secondary coil is grounded to the separate R.F. ground. The 6.5kV - 7.5mA transformer, chassis, 14nF tank capacitor, and primary coil are all grounded to A/C wall plug ground.
I could connect the secondary ground to chassis ground like this, but the chances of R.F. getting back into the house wiring are greater this way. I think that you should have a better ground than the house ground for the secondary because that will give the R.F. current a more friendly path than the house ground and decrease the odds of the two circuits getting mixed up together. This is more important the farther you get from a good ground on the power system. I am not willing to trust a normal house ground to have a low enough impedance to the higher frequency current to keep all parts to a safe voltage level. You need a very low impedance path to ground to keep any exposed metal parts below shocking levels. This coil operates at around 680 KHz, and at that frequency the inductance in even a fairly short length of conductor can have enough reactance to develop quite a few volts across it. With a short, low impedance path, there will not be as significant a rise in voltage from the grounded parts to the ground reference hence less chance of such a differential existing between them and line voltage components.
Before I would try the next configuration, I would have to have a generator in the woods and a dedicated ground rod. No computers within a mile! This would be connecting the base of the secondary coil to the "hot" side of the primary coil, also known as the Oudin configuration.
In this next picture I am holding an Exact-o knife in my hand. The blade does not show in the picture, but the tip of it is about two fingers width toward the toroid from where my thumb and index finger come together in the picture. This is the method I use to map out the E-field around the coil. In total darkness, I run the coil and move toward it until I can just perceive a bit of corona on the point of the knife. At that point, the threshold of corona from a fairly sharp point, the distance to the coil is noted. By taking a series of measurements, a rough guesstimate can be made of the size and shape of the E-field.
It is interesting to note that this plot of the medicine coil E-field so closely matches this one of the E-TESLA5.4 (by Terry Fritz) results plotted by Field plotting program for E-TESLA5.4 by Terry Fritz (by Rainer Schwemmer).
My measurements of the corona threshold surrounding the coil result in a plot that is just a bit more barrel shaped, by that I mean that there is less of a "pinch" in the middle between the toroid and the primary. Of course it is more difficult to judge the point of threshold there because the corona wants to switch from the top of the blade to the bottom of the blade to the tip and back again. It is getting pulled in three directions at once so that may just account for the discrepancy. Good going Guys!