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
The Tidal Waves The Tidal Waves The Tidal Waves were an American garage rock band formed in Roseville, Michigan, in 1964. Despite the young ages of the group members, the Tidal Waves were one of the more accomplished musical acts in the bustling Michigan garage band scene. They are best remembered for their regional hit, a cover version of "Farmer John", which managed to reach the Top 10 of several radio station charts around Detroit. Inspired by the Beatles' momentous appearance on "The Ed Sullivan Show" in February 1964, high school students Tom Wearing (drums, vocals), Mark Karpinski (lead guitar, vocals), and Vic