A Third Generation?

between the coils but that in closer coupling the action of the primary has a damping effect on secondary oscillations. The coils should be isolated so that they can swing freely without interference. This is the argument. (An exception is the magnifying transmitter whose primary and secondary are closely coupled while the third “extra” coil is isolated.)

The most distinctive feature of the Gen II coil, though, is its huge terminal, which is doughnut shaped, a toroid. This is fitted snugly down over the top of the secondary instead of ascending upward like the old Gen I ball.

Gen II builders appreciate that the larger the terminal load the higher the voltage output. Huge amplifications are possible with the technique. And,
as the terminal is enlarged and the voltage magnifies, the increased capacity afforded by the larger terminal brings the resonant frequency down. This is desirable because experimenter spark systems are rarely capable of vibrations above one hundred kilocycles, and the same also argues, of course, for a larger secondary coil as well. My Gen II coil shown here however, is miniature (secondary only 8 inches long by 3 inch diameter), and with the toroid, is resonant up at 540 kc, so it has never seen one-to-one pulsing on the spark system.