(under the class definition) Subject matter wherein the amplifying device is of the vacuum tube type having a positively charged grid (with respect to the cathode) immediately adjacent the cathode, which neutralizes the negative space charge of the electrons emitted from the cathode so that a "virtual cathode" is produced on the side of the space charge grid on which the anode is situated, said tube having a normally negatively biased control grid next to the space charge grid, to which the signal is coupled, and an anode to receive the electrons emitted by the cathode, and which may have additional electrodes between the control grid and the anode.
SEE OR SEARCH THIS CLASS, SUBCLASS:
65, for amplifiers including vacuum tubes of special structural characteristics.
199+, for power or bias voltage supply for amplifiers, see the search notes thereunder.
SEE OR SEARCH CLASS
313, Electric Lamp and Discharge Devices, appropriate subclasses, for discharge device structure, per se. 327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,
524+, for miscellaneous electron tube circuits with space charge grid tubes.
329, Demodulators,
368, for an amplitude demodulator using an electron discharge device of three or more electrodes.
