Beam tetrode
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A beam tetrode, sometimes called a beam power tube, is a type of vacuum tube or thermionic valve that has two grids and forms the electron stream from the cathode into multiple partially collimated be
Radial beam power tetrode, designed for radio frequency use. This type of beam power tube does not use beam confining plates.
6L6 type beam tetrode electrode structures with anode cut open. The beam confining plates are the silver coloured structures to the left and right
Twin beam tetrode RCA-815, used as the bias oscillator tube in the Ampex Model 300 "bathtub" 1/4" full-track professional audio tape recorder
Internal Construction of 4CX250B radial beam power tetrode. Anode structure with attached cooling fins top left, cathode and control grid structure top right, screen grid bottom. Note absence of beam plates, cylindrical symmetry, and slotted screw holes, allowing alignment of the screen grid during manufacture.Inset: Complete valve.
KT88
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The KT88 is a beam tetrode/kinkless tetrode vacuum tube for audio amplification.
Beam tetrode
…in the 6L6. Not long after, the beam tetrode appeared in a variety of offerings, including the 6V6 in December 1936, the MOV KT66 in 1937 and the KT88 in 1956, designed specifically for audio and highly prized by collectors today. After the Philips patent on the suppressor grid had expired, many beam…
KT88 labeled G.E.C. made by GEC/MOV in the U.K.
Four KT88s installed and powered.
Two KT88 made by Sovtek