MDIA 1010 Lecture Notes - Lecture 19: Lee De Forest, Ionosphere, Radio Televizioni Shqiptar
Document Summary
Sources of broadcasting: marconi wireless, telephone broadcasting, am: voice and music, amateur radio. People converted their attics to radio studios. With a little technological skill, anyone could broadcast. An experimental culture led to more discoveries. 200 meters and below, radio amateurs experimented with frequencies: amateur radio culture considered useless. The radio act was passed in the us in 1912. Up until that year, anyone could use radio much as they pleased. Amateur radio was prohibited during ww i for security reasons. Regulating the radio frequency spectrum: 1900: marconi company seeks global monopoly for radio operations, 1906-1913: world radiotelegraph treaties, 1947: international telecommunication union. Reginald fessenden (1866-1932: first am broadcast, 1906, reginald fessenden, a canadian, is credited with the first am broadcast, on 23. It is less suitable for music transmission, but can be operated with a lower transmission power. Fm radio, invented in 1933, takes off after wwii.