- An explanation and picture of the frequency allocation chart.
To prevent radio stations from transmitting signals “on top of each other,” the United States and other national governments in the 1930s began regulating the carrier frequencies and power outputs stations could use. With increased use of the radio spectrum for both public and private use, this regulation has become increasingly important. This is the so-called Frequency Allocation Chart, which shows what kinds of broadcasting can occur in which frequency bands. Detailed radio carrier frequency assignments are much too detailed to present here.