2. Index 1- Definition 2- Etymology 3- History 3.1- Invention 3.2- Development 4- Uses of radio
3. 1- Definition Radio is the transmission of signals by modulation of electromagnetic waves with frequencies below those of visible light.
4. 2- Etymology Radio or radiotelegraphy was called "wireless telegraphy", which was shortened to "wireless” The first recorded in the word radioconductor, coined by the French physicist Édouard Branly in 1897
5. 3- History 1895 by Marconi(spark) 1906 by Fessenden(AM) 1921 by Conrad(shortwave) 1931 by Armstrong(FM) 2000 by XM(digital)
6. 3.1- Inventions 1893 Nikola Telsa electric devices magnetic receivers Meaning and usage of the word "radio" electromagnetic waves and experimentation wireless communication and technical development radio broadcasting and commercialization 1895 Alexander Stepanovich built his first radio receiver
7. 3.2- Development In 1896, Marconi was awarded the British patent. In 1897 he established the world's first radio station on the Isle of Wight, England. Marconi opened the world's first "wireless" factory in Hall Street, Chelmsford, England in 1898, employing around 50 people.
8. 4- Use of radio -Audio -Telephony -Video -Navigation -Radar -Data (digital radio) -Heating -Amateur radio service -Unlicensed radio services -Radio control (RC)
