Ultra High Frequency

UHF ("Ultra High Frequency") stations operate on shorter wavelengths (nominally between 10cm and one metre) than their VHF ("Very High Frequency") counterparts. In North America, for example, channels 14-83 (470-890 MHz) were reserved for over-the-air UHF TV from 1952-1985. In analogue terrestrial television, UHF stations were infamous for covering shorter distances despite typically using far more power. In some countries, the longest-established broadcasters (like NHK in Japan) remained on the few available VHF channels, leaving UHF to struggling independents, small-market stations, fourth networks or educational broadcasters.


 * In Japan, the Otaku O'Clock pattern of programming anime in the wee hours is closely associated with small, independent UHF outlets.
 * In the US, educational PBS, fourth commercial network Fox and Spanish-language Univisión rely disproportionately on UHF stations. See American Television Stations and Broadcasting in the United States for the history behind this.
 * The "UHF discount" was a regulatory loophole by which the limits on common ownership of US OTA TV stations across multiple markets was historically more lax for UHF stations than VHF stations. Now largely obsolete, but some broadcasters (such as ION, the Infomercials Own Network) did take advantage to reach most of the US with owned-and-operated stations on outlying UHF channels.
 * Alas, Technology Marches On. The UK moved all of the telly channels to UHF during the transition from monochrome to colour. Digital TV caused many long-established North American stations (typically CBS and NBC in the US, CBC in Canada) to abandon once-valuable low-VHF channels which they held since The Fifties due to impulse noise and interference. As high-UHF channels are lost to mobile telephone companies, available channels for over-the-air HDTV are becoming increasingly scarce and UHF is valuable. The distinction in frequency has become less significant with modern equipment and with the widespread adoption of cable and satellite.