The radio interference resulting from high-voltage electrical discharges is influenced by three things the nature of the electrical discharge itself, the characteristics of the associated electrical network, and the radio receiver. Each of these factors is studied to determine its contribution to radio interference. It is concluded that the interference arising from corona discharges can be considered as a radio-frequency noise-current spectrum of noise currents distributed over the entire radio frequency spectrum. If radio interference is to be reduced beyond that which can be done by simple filters and tuned circuits, the frequency band of the signal must be reduced with respect to the signal. This can only be accomplished by non-linear circuits which discriminate between the signal and noise on the basis of their different wave forms.