Television broadcasting in the context of "Transmitter"

Sheet music is a handwritten or printed form of musical notation that uses musical symbols to indicate the pitches, rhythms, or chords of a song or instrumental musical piece. Like its analogs – printed books or pamphlets in English, Arabic, or other languages – the medium of sheet music typically is paper (or, in earlier centuries, papyrus or parchment). However, access to musical notation since the 1980s has included the presentation of scores on computer screens and the development of scorewriter computer programs that can notate a song or piece electronically, and, in some cases, "play back" the notated music using a synthesizer or virtual instruments.

The use of the term sheet is intended to differentiate written or printed forms of music from sound recordings (on vinyl record, cassette, CD), radio or TV broadcasts or recorded live performances, which may capture film or video footage of the performance as well as the audio component. In everyday use, sheet music (or simply music) can refer to the print publication of commercial sheet music in conjunction with the release of a new film, TV show, record album, or other unique or popular event which involves music. The first printed sheet music made with a printing press was made in 1473.

Radio is the technology of 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. They can be received by other antennas connected to a radio receiver; this is the fundamental principle of radio communication. In addition to communication, radio is used for radar, radio navigation, remote control, remote sensing, and other applications.

In radio communication, used in radio and television broadcasting, cell phones, two-way radios, wireless networking, and satellite communication, among numerous other uses, radio waves are used to carry information across space from a transmitter to a receiver, by modulating the radio signal (impressing an information signal on the radio wave by varying some aspect of the wave) in the transmitter. In radar, used to locate and track objects like aircraft, ships, spacecraft and missiles, a beam of radio waves emitted by a radar transmitter reflects off the target object, and the reflected waves reveal the object's location to a receiver that is typically colocated with the transmitter. In radio navigation systems such as GPS and VOR, a mobile navigation instrument receives radio signals from multiple navigational radio beacons whose position is known, and by precisely measuring the arrival time of the radio waves the receiver can calculate its position on Earth. In wireless radio remote control devices like drones, garage door openers, and keyless entry systems, radio signals transmitted from a controller device control the actions of a remote device.

Color television (American English) or colour television (British English) is a television transmission technology that also includes color information for the picture, so the video image can be displayed in color on the television set. It improves on the monochrome or black-and-white television technology, which displays the image in shades of gray (grayscale). Television broadcasting stations and networks in most parts of the world transitioned from black-and-white to color broadcasting between the 1960s and the 1980s. The invention of color television standards was an important part of the history and technology of television.

Transmission of color images using mechanical scanners had been conceived as early as the 1880s. A demonstration of mechanically scanned color television was given by John Logie Baird in 1928, but its limitations were apparent even then. Development of electronic scanning and display made a practical system possible. Monochrome transmission standards were developed prior to World War II, but civilian electronics development was frozen during much of the war. In August 1944, Baird gave the world's first demonstration of a practical fully electronic color television display. In the United States, competing color standards were developed, finally resulting in the NTSC color standard that was compatible with the prior monochrome system. Although the NTSC color standard was proclaimed in 1953, and limited programming soon became available, it was not until the early 1970s that color television in North America outsold black-and-white units. Color broadcasting in Europe did not standardize on the PAL or SECAM formats until the 1960s.

Terrestrial television, or over-the-air television (OTA) is a type of television broadcasting in which the content is transmitted via radio waves from the terrestrial (Earth-based) transmitter of a TV station to a TV receiver having an antenna. The term terrestrial is more common in Europe and Latin America, while in Canada and the United States it is called over-the-air or simply broadcast. This type of TV broadcast is distinguished from newer technologies, such as satellite television (direct broadcast satellite or DBS television), in which the signal is transmitted to the receiver from an overhead satellite; cable television, in which the signal is carried to the receiver through a cable; and Internet Protocol television, in which the signal is received over an Internet stream or on a network utilizing the Internet Protocol. Terrestrial television stations broadcast on television channels with frequencies between about 52 and 600 MHz in the VHF and UHF bands. Since radio waves in these bands travel by line of sight, reception is generally limited by the visual horizon to distances of 64–97 kilometres (40–60 miles), although under better conditions and with tropospheric ducting, signals can sometimes be received hundreds of kilometers distant.

Terrestrial television was the first technology used for television broadcasting. The BBC began broadcasting in 1929 and by 1930 many radio stations had a regular schedule of experimental television programmes. However, these early experimental systems had insufficient picture quality to attract the public, due to their mechanical scan technology, and television did not become widespread until after World War II with the advent of electronic scan television technology. The television broadcasting business followed the model of radio networks, with local television stations in cities and towns affiliated with television networks, either commercial (in the US) or government-controlled (in Europe), which provided content. Television broadcasts were in greyscale (called black and white) until the transition to color television in the 1960s.

AM broadcasting is radio broadcasting using amplitude modulation (AM) transmissions. It was the first method developed for making audio radio transmissions, and is still used worldwide, primarily for medium wave (also known as "AM band") transmissions, but also on the longwave and shortwave radio bands.

The earliest experimental AM transmissions began in the early 1900s. However, widespread AM broadcasting was not established until the 1920s, following the development of vacuum tube receivers and transmitters. AM radio remained the dominant method of broadcasting for the next 30 years, a period called the "Golden Age of Radio", until television broadcasting became widespread in the 1950s and received much of the programming previously carried by radio. Later, AM radio's audiences declined greatly due to competition from FM (frequency modulation) radio, Digital Audio Broadcasting (DAB), satellite radio, HD (digital) radio, Internet radio, music streaming services, and podcasting.