Millikan, Robert Andrews, Gale, Henry Gordon · Boston : Ginn and Co. · leaf 494
29 491. The vacuum tube. There are several devices by whichthe voice waves may modulate, or vary the amplitude of, thecarrier waves, the most important being the highly exhausted vacuum tube (see Fig. 465, the halftone opposite p. 441,and the drawing and legend opposite p. 33). In attempting to… … -Plate -Filament-Grid—Filament
Physics
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