VACUUM TUBE FOR ANALOG AMPLIFICATION AND VACUUM TUBE

摘要

PROBLEM TO BE SOLVED: To provide a vacuum tube that has a structure close to an inexpensive and easily available fluorescent display tube and is easily used as an analog amplifier for audio signals.;SOLUTION: A vacuum tube has: a filament that emits thermal electrons and is linearly stretched; and two pairs of grids and anodes. Both the anodes are formed on the same surface of a planar substrate. The filament is disposed in parallel to the planar substrate at a position facing both the anodes. Each of the grids confronts the anode of the same pair and is spaced from the anode at a predetermined first interval, and disposed between the anode and the filament so as to be spaced from the filament at a predetermined second interval. A filament intermediate fixing part for fixing the filament at a position corresponding to an intermediate point between the two pairs of anodes is provided. Further, the predetermined first interval may be set in a range of 0.15 mm or more and 0.35 mm or less, and the predetermined second interval may be set in a range of 0.2 mm or more and 0.6 mm or less.;SELECTED DRAWING: Figure 1;COPYRIGHT: (C)2018,JPO&INPIT