AM Broadcasting

AM broadcasting is a radio broadcasting technology, which employs amplitude modulation transmissions.

In electronics and telecommunications, modulation is the process of varying one or more properties of a periodic waveform, called the carrier signal, with a modulating signal that typically contains information to be transmitted.

Amplitude modulation is a modulation technique used in electronic communication, most commonly for transmitting information via a radio carrier wave.

The amplitude of a periodic variable is a measure of its change over a single period.

AM Radio History by Largest Dams

It was the first method developed for making audio radio transmissions, and is still used worldwide, primarily for medium wave transmissions, but also on the longwave and shortwave radio bands.

In radio, longwave, long wave or long-wave, and commonly abbreviated LW, refers to parts of the radio spectrum with wavelengths longer than what was originally called the medium-wave broadcasting band.

Medium wave is the part of the medium frequency radio band used mainly for AM radio broadcasting.

The strange things you hear on AM radio, Part 2! by VWestlife

The earliest experimental AM transmissions were begun in the early 1900s.

However, widespread AM broadcasting was not established until the 1920s, following the development of vacuum tube receivers and transmitters.

In electronics, a vacuum tube, an electron tube, or colloquially a tube or valve, is a device that controls electric current flow in a high vacuum between electrodes to which an electric potential difference has been applied.

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 most of the programming previously carried by radio.

The old-time radio era, sometimes referred to as the Golden Age of Radio, was an era of radio programming in the United States during which radio was the dominant electronic home entertainment medium.

Television or TV is a telecommunication medium used for transmitting moving images in monochrome, or in color, and in two or three dimensions and sound.

Subsequently, AM radio's audiences have also greatly shrunk due to competition from FM radio, Digital Audio Broadcasting, satellite radio, HD radio and Internet streaming.

Satellite radio is defined by the International Telecommunication Union 'S ITU Radio Regulations as a broadcasting-satellite service.

AM transmissions are much more susceptible than FM or digital signals are to interference, and often have lower audio fidelity.

Thus, AM broadcasters tend to specialise in spoken-word formats, such as talk radio, all news and sports, leaving the broadcasting of music mainly to FM and digital stations.

Talk radio is a radio format containing discussion about topical issues.