Very high frequency

Very high frequency (VHF) is the ITU-designated range ^[1] of radio frequency electromagnetic waves from 30 MHz to300 MHz, with corresponding wavelengths of one to ten meters. Frequencies immediately below VHF are denoted high frequency (HF), and the next higher frequencies are known as ultra high frequency (UHF).

Common uses for VHF are FM radio broadcasting, television broadcasting, land mobile stations (emergency, business, private use and military), long range data communication up to several tens of kilometres with radio modems, amateur radio, and marine communications. Air traffic control communications and air navigation systems (e.g. VOR, DME & ILS) work at distances of 100 kilometres or more to aircraft at cruising altitude.

VHF was previously used for analog television stations in the US.

Antennas[edit]

VHF is the first band at which wavelengths are small enough to make efficient transmitting antennas for handheld devices, so the VHF and UHF wavelengths are used for handheld transceivers and walkie talkies. Fixed station antennas are usually based on the dipole, while portable radios usually use whips or rubber ducky antennas. The Yagi antenna is the most widely used as a high gain or "beam" antenna. Helical and turnstile antennas are used for satellite communication since they employ circular polarization. For even higher gain, multiple Yagis or helicals can be mounted together as an array antennas. Television and FM broadcasting stations use collinear arrays of specialized dipole antennas such as batwing antennas.

Universal use[edit]

Certain subparts of the VHF band have the same use around the world. Some national uses are detailed below.

• 108–118 MHz: Air navigation beacons VOR and Instrument Landing System localiser.
• 118–137 MHz: Airband for air traffic control, AM, 121.5 MHz is emergency frequency
• 144–146 MHz: Amateur radio. In some countries 144–148 MHz.