VHF

VHF, in full very high frequency, conventionally defined portion of the electromagnetic spectrum including any radiation with a wavelength between 1 and 10 metres and a frequency between 300 and 30 megahertz. VHF signals are widely employed for television and radio transmissions. In the United States and Canada, television stations that broadcast on channels 2 through 13 use VHF frequencies, as do FM radio stations. Many amateur radio operators also transmit on frequencies within the VHF band.

VHF waves, unlike longer waves, are not strongly reflected from the atmosphere; therefore, they do not bend readily around the Earth’s curvature and cannot be transmitted beyond the horizon. Their range is further limited by their inability to pass through hills or large structures. Accordingly, VHF waves are limited to use in short-range, line-of-sight communications, including radio and television broadcasting, and in electronic navigation systems. They are especially suited to such applications because their reception is not impaired by random electromagnetic noise (“static”) of longer wavelengths. Because of their limited transmission range, VHF signals of the same frequency can be used by transmitters several hundred miles apart without interfering with one another. See also UHF.