Turn of the Century 



Lee DeForest

Lee deForest (1873-1961) further develops the basic electron-valve made by Ambrose Fleming by adding a grid to it. This grid effectively controls the flow of electrons through the valve. A signal applied to this grid effectively allows the current through the valve to be controlled, thus creating the first amplifier element. Lee deForest called his invention the audion. It would later be known under its more common name: the Triode.





Pioneer Electronics research Lab is established at the corner of Channing Avenue and Emerson Street in Palo Alto. Here Lee Deforest would go on and develop the first practical application of his audion as an amplifier and oscillator. 

910 Emerson Street Palo Alto.

Cyril Ewell starts the Federal Telegraph company after having acquired the rights to the Poulsen Arc Transmitter form Valdemar Poulsen. The first wireless telegraph station was built on 48th avenue between Noriega and Ortega Street in San Francisco. In 1912 a second ground station was built at Point San Bruno, just south of San Francisco. At its construction it had the world’s largest antenna towers, rising up to 440 feet. The antenna itself contained 35000 feet of wire.

Image above part of the California Digital Library.

Copyright © 2011 The Regents of The University of California


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Charles D . Herrold creates the world’s first radio broadcast station in the Garden city bank building in downtown San Jose (today’s capital of Silicon Valley). Today there is still a broadcast studio in operation in the building at the southwest corner of First Street and San Fernando in downtown San Jose. A plaque in the entrance serves as proof of the radio broadcast origins.




http://www.bayarearadio.org/schneider /kqw.shtml


Philo Taylor Farnsworth invented and patented the first all-electronic television system. Farnsworth had his ‘lab’ in a cellar on 202 Green Street San Francisco. In September of that year he succeeded in the first transmission of an all-electronic television image.

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Philo Farnsworth holding an early version of the 'image dissector"


202 Green Street. San Francisco.

© Vincent Himpe 2016