1. AN INDUCTANCE COIL WOUND FROM TWO CONTINUOUS CONDUCTORS ABOUT A CORE IN A PLURALITY OF CONCENTRIC LAYERS, EACH LAYER COMPRISING TWO SYMMETRICAL, AXIALLY ALIGNED SECTIONS, EACH SECTION BEING WOUND FROM ONE CONDUCTOR, THE TWO SECTIONS OF ANY LARGER BEING WOUND HELICALLY IN OPPOSITE AXIAL DIRECTIONS BETWEEN THE RESPECTIVE ENDS OF THE COIL AND A MIDPOINT THEREOF, THE THUS FORMED TURNS OF BOTH CONDUCTORS CONTINUING IN THE SAME AXIAL WINDING DIRECTION WITHIN THE FIRST TWO LAYERS, THE AXIAL WINDING DIRECTIONS OF BOTH CONDUCTORS CHANGING AT A MIDPOINT IN A PLURALITY OF SUBSEQUENT LAYERS WITHIN THE FIRST HALF OF THE COIL WINDING, THE WINDINGS OF BOTH CONDUCTORS CONTINUING IN THE SAME AXIAL WINDING DIRECTIONS WITHIN TWO LAYERS APPROXIMATELY HALF WAY THROUGH THE COIL, THE AXIAL WINDING DIRECTIONS OF BOTH CONDUCTORS CHANGING AT A MIDPOINT IN A PLURALITY OF LAYERS WITHIN THE SECOND HALF OF THE COIL WINDING, THE WINDINGS OF BOTH CONDUCTORS CONTINUING IN THE SAME AXIAL WINDING DIRECTIONS, WITHIN THE TWO LAST LAYERS.