-
Nikola Teslesa
He then established his own lab where he
invented, among other things, the Tesla coil, an induction
coil widely used in radio. -
Heinrich Hertz
proved that electricity can be
transmitted in electromagnetic
waves. -
Alternator-Transmitter Development
Radio signals were originally produced by spark transmitters, which were noisy and inefficient. So experimenters whose signals went out on a single frequency, and which could also transmit full-audio signals. -
Guglielmo Marconi
italian inventor and electical engineer, known for his pioneering work on long-distance radio transmission and for his development of Marconi's law and a radio telegraph system. -
Audion and Vacuum-tube Receiver Development
Lee DeForest invented a three-element vacuum-tube detector which he called an Audion, but initially it was so crude and unreliable that it was little more than a curiosity. After a lull of a few years, more capable scientists and engineers, led by AT&T's Dr. Harold Arnold, improved vacuum-tubes into robust and powerful amplifiers, which would revolutionize radio reception. -
Pioneering Amateurs
Radio captured the imagination of thousands of ordinary persons who wanted to experiment with this amazing new technology. Until late 1912 there was no licencing or regulation of radio transmitters in the United States, so amateurs -- known informally as "hams" -- -
Expanded Audion and Vacuum-tube Development
he wartime consolidation of the radio industry under government control led to important advances in radio equipment engineering and manufacturing, especially vacuum-tube technology. Still, some would look toward the day when vacuum-tubes would be supplanted by something more efficient and compact, although this was another development which would take decades to be realized. -
Broadcasting After World War One
Although still unfocused, scattered broadcasting activities, taking advantage of improvements in vacuum-tube technology, accelerated after the end of the Great War. Initially there was a shortage of equipment, especially vacuum-tubes, due to ongoing patent disputes, and many of the early efforts were government related or by persons who had access to surplus military equipment. But the experiments continued to expand, as the radio industry returned to civilian control. -
Broadcasting Becomes Widespread
Led by Westinghouse's 1920 and 1921 establishment of four well-financed stations -- located in or near Pittsburgh, Boston, Chicago and New York City -- there was a growing sense of excitement as broadcasting activities became more organized. In December, 1921, the Department of Commerce issued regulations formally establishing a broadcast service. Then, in early 1922, a "broadcasting boom" occurred, as a sometimes chaotic mix of stations, sponsored by a wide range of businesses, organizations an -
The Development of Radio Networks
The introduction of vacuum-tube amplification for telephone lines allowed AT&T to experiment with sending speeches to distant audiences that listened over loudspeakers. The next step would be to use the lines to interconnect radio stations, and in December, 1921 a memo written by two AT&T engineers, J. F. Bratney and H. C. Lauderback, -
XM Satellite Radio
XM Satellite Radio s one of two satellite radio services in the United States and Canada, operated by Sirius XM Radio. It provides pay-for-service radio, analogous to cable television. -
Digital Radio Mondiale (DRM) – digital AM radio with FM-quality sound
Digital AM, digital audio broadcasting, digital radio, DRM, medium wave. I. INTRODUCTION. DRM (Digital Radio Mondiale) is the only universal non-proprietary digital radio
