Please go through the following links:


Triode


http://en.wikipedia.org/wiki/Triode


http://books.google.co.uk/books?id=Q...triode&f=false


http://onlinelibrary.wiley.com/doi/1...00506/abstract


http://www.scribd.com/doc/14804996/The-Triode-Valve


http://en.wikipedia.org/wiki/Electrodes


Tetrode


http://en.wikipedia.org/wiki/Tetrode


http://en.wikipedia.org/wiki/Beam_tetrode


http://www.allaboutcircuits.com/vol_3/chpt_13/4.html


http://www.r-type.org/static/grid02.htm


http://www.ifwtech.co.uk/g3sek/board.../tetrode-1.htm


http://dictionary.reference.com/browse/tetrode


http://www.angelfire.com/nb/ni4l/gu84b.html


Pentode


http://en.wikipedia.org/wiki/Pentode


http://www.allaboutcircuits.com/vol_3/chpt_13/6.html


http://www.r-type.org/static/grid03.htm


http://www.freewebs.com/valvewizard/pentode.html


http://www.britannica.com/EBchecked/...450472/pentode


http://www.yourdictionary.com/pentode


Hope you will get a bit from above pasted links that you require !

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