Technical topics

摘要

Centennial of the audion triode. 'TT', January 2004, noted the approaching centennial of the 1904 invention by Professor (Sir) Ambrose Fleming of the thermionic diode, based on the 1883 Edison Effect. This event marked the entry of thermionic valves into the then emerging field of radio communication. But the Fleming diode was developed as a new form of RF detector; indeed it marked only one, and not necessarily the most sensitive, of a number of approaches to the detection of weak radio signals.