Radio receiver crude triode, was invented in 1906 by Lee De Forest as a more sensitive detector for radio receivers, by adding a third electrode to the thermionic diode detector, the Fleming valve. It was not widely used until its amplifying ability was recognized around 1912. The first tube receivers, invented by De Forest and built by hobbyists until the mid 1920s, used a single Audion which functioned as a grid-leak detector which both rectified and amplified the radio signal. There was uncertainty about the operating principle of the Audion until Edwin Armstrong explained both its amplifying and demodulating functions in a
Jim McDonald (electrical engineer) Jim McDonald (electrical engineer) Sir James McDonald FREng FRSE FInstP FIET is a British educator, serving as Principal and Vice-Chancellor of the University of Strathclyde since 2009. He is also a visiting professor at NYU Tandon School of Engineering. After seven years of work within the UK Electricity Supply Industry, McDonald joined Strathclyde University in 1984 and became Professor of Electrical Power Systems in 1993. In 2001 he was invited to deliver the MacMillan Memorial Lecture to the Institution of Engineers and Shipbuilders in Scotland. He chose the subject "Electric Propulsion in Marine Applications: An Electrical Engineer's Viewpoint". In 2006