a vacuum tube having five electrodes, usually a plate, three grids, and a cathode, within the same envelope.
Origin of pentode
1915–20; pent- + -ode2
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for pentode
Historical Examples of pentode
Remember how he went to all the trouble of building a pentode vacuum tube for a job that could have been done by transistors.Anything You Can Do
Gordon Randall Garrett
an electronic valve having five electrodes: a cathode, anode, and three grids
(modifier) (of a transistor) having three terminals at the base or gate
Word Origin for pentode
C20: from penta- + Greek hodos way
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Any electron tube with the basic structure and functionality of a triode, but including two extra electrodes, a screen and a suppressor grid. The screen helps the tube respond well at high frequencies (as in a tetrode), while a negatively charged suppressor grid adjacent to the plate prevents secondary emission of electrons from the plate, increasing the efficiency of the tube. See more at suppressor.
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