to the same (though less visible) in Fig. 4.

The spark gap electrodes were made of brass 4-40 acorn nuts with a radius of curvature of about 2.5 mm. The gap spacings used were roughly 3.0, 3.0, 3.0, 3.0, 3.0, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.0, and 8.0 mm, from bottom to top.

When installed, the plastic pipe form of the solenoid muffled and blocked the spark gap noise and light emission significantly. White plastic was used for the U-channel and solenoid pipe so that the interior space resembled an integrating cavity, in case it might reduce gap jitter and losses. Note that gap quenching is not critical here unlike in spark-gap Tesla transformers (SGTTs), since energy is not transferred between resonant circuits.

Two different toroidal output terminals were used for the data shown. The first, shown in Figs. 1 & 4, had a maximum width of 4.8 cm, height of 2.9 cm, and an estimated electrostatic capacitance of 5.5 pF. In Fig. 3, a second terminal was placed above the first terminal. This terminal had a maximum width of 15.3 cm, height of 7.0 cm, and an estimated electrostatic capacitance of 6.0 pF. 