Tower 4 tuning house
Not much remains to be seen. The bowl insulator can be seen at left. RF power was applied to the tower via a copper tube running from the output of the tuning network, which was mounted on a metal shelf, through the bowl insulator and onto the tower. The copper tube was coiled in one or two large loose turns as a lightning choke. If lightning should strike, it was hoped that the pulse would be stopped by the loose turns and encouraged instead to leap the "ball gap," which consisted of two steel balls on rods, one attached to the tower and the other to ground, in close proximity to each other, forming a spark gap. Inside the tube ran the three-conductor wiring for the tower lights. Inside the shack under the metal shelf was the tower lighting choke which served to isolate the AC power feeding the lights from the RF. The neutral wire was bonded to the tower structure, and through the choke, the tower was (as described by the station's first chief engineer John Whitacre) "both AC- and DC-wise grounded".
