my next coil will be a very low frequency of 13 khz. i am planing on building this coil, mounted on a trailer, so that i can take it to schools and functions for displays. it will be driven from a self contained 100kva kohler generator and pole pigs rangeing from 25 kva to 150kva.

these tanks will be the formers for the vlf coil, two tanks will be glassed together, end to end with the flanges on each end. one for topload mounting and the other for secondary mounting. i got these tanks from rmi titainium, they are 1" thick spun fiberglass with an 1/8" polyethylene liner, my first thoughts were to put the secondary on the inside, in a heilical pattern. then using a lead screw actuator, i could raise and lower the primary coilform in and out to effect coupling? for tuning, i have devised a stepper drive on anouther lead screw that would rotate a tap point around the winding.

coupling could be a problem, but i am confident that the thickness of the glass and the poly will stop all flashovers that inhibit tight coupling in other systems. the tanks mesure an od of 22" and two together will give me a winding area of 120" available