The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.
a radio receiving tube in which a special design and arrangement of the electrodes are used to focus a continuous stream of electrons into a narrow beam. Tubes of this type include beam tetrodes, rod-grid tubes, and converter tubes.
The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.