The Problem of Congestion in High-Frequency Broadcast Bands

The usefulness of the high-frequency spectrum for international broadcasting is in serious jeopardy. A rapid increase in the number of transmitters operating in the broadcast bands between 3 and 30 MHz has resulted in a corresponding increase in co-and adjacent-channel interference levels. At present, a condition of extreme congestion exists, with many channels over-loaded by a factor of three during certain peak broadcast periods.