Radio Noise Aging Characteristics of Small Aluminum Conductors

A series of tests were rmn on clean, greased, and scratched surfaces to determine their radio noise aging characteristics. The conductors were aged in the unenergized and energized state. The energized conductors acquired a black coating which was formed on the surface after a week of operation. This black coating stabilizes the corona start voltage of new conductors with smooth surfaces. The radio noise performance of the aged scratched conductors approaches the performance of the aged smooth conductors after a period of 104 days in the energized state.