Radio Equipment, Aerials Radio aerials sited on the roof of the Science Museum, London, 1980s

Radio Equipment, Aerials Radio aerials sited on the roof of the Science Museum, London, 1980s. In order to be transmitted, the information in a radio signal is used to modulate a radio-frequency wave. The modulated signal is then amplified, and projected into space by a transmitting antenna. The signals can then be picked up by the aerial of a radio receiver tuned in to the wavelength of the transmission. The first radio signals were successfully sent by Guglielmo Marconi (1874-1937) in 1894. Marconi devised a means of sending telegraphic messages, but it was not until 1906 that Reginald Fessenden (1866-1932) developed amplitude modulation, enabling him to make the first sound broadcast. This marked the birth of radio broadcasting as we know it today. ©SSPL/Science Museum