Fundamentals Of Electronics - A note from history... The simplest vacuum tube, the diode invented in 1904 by John Ambrose Fleming, contains only a heated electron-emitting cathode and an anode. Electrons can
Broadcast Electronics - Fleming patents vacuum tube, November 16, 1904 In the 1904 Fleming was granted a GB patent Nr 24850 (see the patent) for Improvements in Instruments for Detecting and Measuring
![Fleming's Diode Valve 1904. The Fleming valve, also called the Fleming oscillation valve, was a vacuum tube (or "thermionic valve") invented in 1904 by John Ambrose Fleming as a detector for early Fleming's Diode Valve 1904. The Fleming valve, also called the Fleming oscillation valve, was a vacuum tube (or "thermionic valve") invented in 1904 by John Ambrose Fleming as a detector for early](https://cdn.superstock.com/1746/Comp/1746-21131550.webp)