Vacuum tube

In electronics, a vacuum tube (American English) or (thermionic) valve (British English) is a device generally used to amplify, or otherwise modify, a signal. Once used in most electronic devices, vacuum tubes are now used only in specialized applications. For most purposes, the vacuum tube has been replaced by the much smaller and less expensive transistor, either as a discrete device or in an integrated circuit. At the start of the 21st century there has been renewed interest in the vacuum tube, this time in the form of the Field-emitter microtube.

External links and references

Books and articles

• Spangenburg K.R., Vacuum Tubes, McGraw-Hill, 1948
• Millman, J. & Seely, S. Electronics, 2nd ed. McGraw-Hill, 1951.
• Shiers, George, "The First Electron Tube", Scientific American, March 1969, p. 104.
• Tyne, Gerald, Saga of The Vacuum Tube, Ziff Publishing, 1943, (reprint 1994 Prompt Publications), pp. 30-83.
• Stokes, John, 70 Years of Radio Tubes and Valves, Vestal Press, NY, 1982, pp. 3-9.
• Thrower, Keith, History of The British Radio Valve to 1940, MMA International, 1982, pp 9-13.

Web links

• "How vacuum tubes really work" - John Harper's webpage about thermionic emission and vacuum tube theory, using introductory college-level mathematics.
• "The invention of the thermionic valve". Fleming discovers the thermionic (or oscillation) valve, or 'diode'.
• "Tubes Vs. Transistors : Is There An Audible Difference?" - AES paper on audible differences in sound quality between vacuum tubes and transistors.
• The Virtual Valve Museum
• The Tube Collectors Association