 The ITU over the past 50 years — in consideration of the various population densities of its members — officially mandates a minimum of 5 radials for an entire antenna system.Although many broadcasting regulators around the world had to find some way of regulating longwave and mediumwave antenna patterns and power, only the FCC chose to implement the radial method in its fullest form.The FCC decision to fully implement radials evolved from 1925 to 1975.