(under subclass 280) Subject matter where the coupling is a fixed tuned circuit.
(1) Note. The systems to be found here comprise tuned circuit means in the antenna or collector receiver coupling circuits and are not intended to be utilized as preselector or tuning means for the receiver but often times are utilized to determine the frequency of the signal accepted by the antenna or collector and transmitted to the receiver input terminals. For wave selecting (i.e., tuning) circuits utilized for the determination of the frequency to which a receiver is tuned, search this class (455), subclass 193.
SEE OR SEARCH THIS CLASS, SUBCLASS:
283+, for receivers using tuned circuits in the antenna coupling for undesired signal or noise control.
289, for receivers with variable tuned circuits in antenna coupling systems.
340, for receivers using variable resonant or tuned circuits in coupling systems.
