Radio propagation antennas (monopoles) are required. Since the ground is not a perfect electrical conductor, ground waves are attenuated as they follow the Earth’s surface. Attenuation is proportional to frequency, so ground waves are the main mode of propagation at lower frequencies, in the MF, LF and VLF bands. Ground waves are used by radio broadcasting stations in the MF and LF bands, and for time signals and radio navigation systems. At even lower frequencies, in the VLF to ELF bands, an Earth-ionosphere waveguide mechanism allows even longer range transmission. These frequencies are used for secure military communications. They can also penetrate
Radio Waves (song) Radio Waves (song) "Radio Waves" is the opening track from Roger Waters' second solo studio album, "Radio K.A.O.S." It was chosen as the lead single for the album, released worldwide in May 1987. "Radio Waves" introduces the main character, Billy, a disabled man who finds a way to talk and become friends with a radio DJ. Billy is gifted and has the miracle of hearing and interpreting radio waves in his head. He explores a cordless phone which was hidden in his wheelchair by his brother Benny, after destroying and robbing a store. Recognising its similarity to a radio, he