In electronics and telecommunications, a radio transmitter or just transmitter is an electronic device which produces radio waves with an antenna. The transmitter itself generates a radio frequency alternating current, which is applied to the antenna. When excited by this alternating current, the antenna radiates radio waves.
Broadcasting is the distribution of audio or video content to a dispersed audience via any electronic mass communications medium, but typically one using the electromagnetic spectrum, in a one-to-many model. Broadcasting began with AM radio, which came into popular use around 1920 with the spread of vacuum tube radio transmitters and receivers. Before this, most implementations of electronic communication were one-to-one, with the message intended for a single recipient. The term broadcasting evolved from its use as the agricultural method of sowing seeds in a field by casting them broadly about. It was later adopted for describing the widespread distribution of information by printed materials or by telegraph. Examples applying it to "one-to-many" radio transmissions of an individual station to multiple listeners appeared as early as 1898.
High frequency (HF) is the ITU designation for the range of radio frequency electromagnetic waves between 3 and 30 megahertz (MHz). It is also known as the decameter band or decameter wave as its wavelengths range from one to ten decameters. Frequencies immediately below HF are denoted medium frequency (MF), while the next band of higher frequencies is known as the very high frequency (VHF) band. The HF band is a major part of the shortwave band of frequencies, so communication at these frequencies is often called shortwave radio. Because radio waves in this band can be reflected back to Earth by the ionosphere layer in the atmosphere – a method known as "skip" or "skywave" propagation – these frequencies are suitable for long-distance communication across intercontinental distances and for mountainous terrains which prevent line-of-sight communications. The band is used by international shortwave broadcasting stations (3.95–25.82 MHz), aviation communication, government time stations, weather stations, amateur radio and citizens band services, among other uses.
TACAMO is a United States military system of survivable communications links designed to be used in nuclear warfare to maintain communications between the decision-makers and the triad of strategic nuclear weapon delivery systems. Its primary mission is serving as a signals relay, where it receives orders from a command plane such as Operation Looking Glass, and verifies and retransmits their Emergency Action Messages (EAMs) to US strategic forces. As it is a dedicated communications post, it features the ability to communicate on virtually every radio frequency band from very low frequency (VLF) up through super high frequency (SHF) using a variety of modulations, encryptions and networks, minimizing the likelihood an emergency message will be jammed by an enemy. This airborne communications capability largely replaced the land-based extremely low frequency (ELF) broadcast sites which became vulnerable to nuclear strike.
Radio propagation is the behavior of radio waves as they travel, or are propagated, from one point to another in vacuum, or into various parts of the atmosphere. As a form of electromagnetic radiation, like light waves, radio waves are affected by the phenomena of reflection, refraction, diffraction, absorption, polarization, and scattering. Understanding the effects of varying conditions on radio propagation has many practical applications, from choosing frequencies for amateur radio communications, international shortwave broadcasters, to designing reliable mobile telephone systems, to radio navigation, to operation of radar systems.
Wireless power transfer (WPT), wireless power transmission, wireless energy transmission (WET), or electromagnetic power transfer is the transmission of electrical energy without wires as a physical link. In a wireless power transmission system, an electrically powered transmitter device generates a time-varying electromagnetic field that transmits power across space to a receiver device; the receiver device extracts power from the field and supplies it to an electrical load. The technology of wireless power transmission can eliminate the use of the wires and batteries, thereby increasing the mobility, convenience, and safety of an electronic device for all users. Wireless power transfer is useful to power electrical devices where interconnecting wires are inconvenient, hazardous, or are not possible.
WGTV is a PBS member television station licensed to Athens, Georgia, United States, a legacy of the station's early years as a service of the University of Georgia (UGA). Owned by the Georgia Public Telecommunications Commission, it is the flagship station of the statewide Georgia Public Broadcasting (GPB) television network, serving the Atlanta metropolitan area from a transmitter atop Stone Mountain just east of Atlanta.
Stratovision was an airborne television transmission relay system using aircraft flying at high altitudes. In 1945 the Glenn L. Martin Company and Westinghouse Electric Corporation originally proposed television coverage of small towns and rural areas, as well as the large metropolitan centers, by fourteen aircraft that would provide coverage for approximately 78% of the people in the United States. Although this was never implemented, the system has been used for domestic broadcasting in the United States, and by the U.S. military in South Vietnam and other countries.
The Winter Hill transmitting station is a broadcasting and telecommunications site on Winter Hill, at the south eastern boundary of the Borough of Chorley, Lancashire, England, and above Bolton. It is owned and operated by Arqiva.
WYCC was a public television station in Chicago, Illinois, United States. It was last owned by not-for-profit broadcasting entity Window to the World Communications, Inc., alongside PBS member station WTTW and classical music radio station WFMT. WYCC's operations were housed with WTTW and WFMT in the Renée Crown Public Media Center, located at 5400 North Saint Louis Avenue in the city's North Park neighborhood; WYCC and WTTW shared transmitter facilities atop the Willis Tower on South Wacker Drive in the Chicago Loop. WYCC previously maintained studios at Kennedy–King College on South Union Avenue and Halsted Parkway in the Englewood neighborhood.
Radio masts and towers are typically tall structures designed to support antennas for telecommunications and broadcasting, including television. There are two main types: guyed and self-supporting structures. They are among the tallest human-made structures. Masts are often named after the broadcasting organizations that originally built them or currently use them.
WPSU-TV is a PBS member television station licensed to Clearfield, Pennsylvania, United States, serving West-Central Pennsylvania. Owned by the Pennsylvania State University as part of Penn State Public Media, it is sister to NPR member WPSU and student radio station WKPS. The three stations share studios at Innovation Park on Penn State's University Park campus in State College. WPSU-TV's primary transmitter is located seven miles (11 km) north of Clearfield in Lawrence Township, with a secondary transmitter in Pine Grove Mills, Pennsylvania.
Arkansas PBS is a state network of PBS member television stations serving the U.S. state of Arkansas. It is operated by the Arkansas Educational Television Commission, a statutory non-cabinet agency of the Arkansas government operated through the Arkansas Department of Elementary and Secondary Education, which holds the licenses for all of the public television stations based in the state. The commission is managed by an independent board of university and education officials, and gubernatorial appointees representing each of Arkansas's four congressional districts. Along with offering television programs supplied by PBS and various independent distributors, the network produces public affairs, cultural and documentary programming as well as sports events sanctioned by the Arkansas Activities Association (AAA).
A television station is a set of equipment managed by a business, organisation or other entity such as an amateur television (ATV) operator, that transmits video content and audio content via radio waves directly from a transmitter on the earth's surface to any number of tuned receivers simultaneously.
WIUM is a 50,000-watt radio station licensed to Macomb, Illinois, in west-central Illinois. Western Illinois University is the station licensee, authorized by the Federal Communications Commission.
Satellite Instructional Television Experiment or SITE was an experimental satellite communications project launched in India in 1975, designed jointly by NASA and the Indian Space Research Organization (ISRO). The project made available informational television programs to rural India. The main objectives of the experiment were to educate the financially backward and academically illiterate people of India on various issues via satellite broadcasting, and also to help India gain technical experience in the field of satellite communications.
The Wiederau transmitter is the oldest broadcasting facility in Saxony. It is located near Wiederau, a village which is part of the municipality of Pegau, and is used for medium-wave, FM and Television broadcasting.
A radio communication is a set of equipment necessary to carry on communication via radio waves. Generally, it is a receiver or transmitter or transceiver, an antenna, and some smaller additional equipment necessary to operate them. They play a vital role in communication technology as they are heavily relied on to transfer data and information across the world.
Radio-frequency (RF) engineering is a subset of electrical engineering involving the application of transmission line, waveguide, antenna and electromagnetic field principles to the design and application of devices that produce or use signals within the radio band, the frequency range of about 20 kHz up to 300 GHz.
Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 3 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmitter connected to an antenna which radiates the waves, and received by another antenna connected to a radio receiver. Radio is widely used in modern technology, in radio communication, radar, radio navigation, remote control, remote sensing, and other applications.
