(under the class definition) Subject matter including at least two amplifying devices each of which is of a type
different from the other.
(1) Note. When each of the amplifying devices is of a type which is classified in different subclasses of this class providing for such different types of amplifying devices, such as subclass 8 for saturable reactor type and subclass 44 for electron beam type, classification is in this subclass. Where the different types of amplifying devices are types provided for in coordinate subclasses indented under a major genus type, classification is not in this subclass, but in the appropriate subclasses indented under subclass 250. Diverse type vacuum tube amplifying devices combined in an amplifier are classified in subclass 3 when each of the diverse type amplifying devices is of a type separately provided for by a subclass in this class, as for example, a traveling wave type amplifier classified in subclass 43 and an electron beam tube amplifying device classified in subclasses 44+. Where different types of vacuum tubes are involved, only one of which is provided for by a separate subclass, classification is not in subclass 3 but in the subclass providing for an amplifier having an amplifier device of that type. Combinations of vacuum tube and gaseous tube amplifiers are classified herein. Diode vacuum tube amplifiers combined with any other type of vacuum tube amplifier, whether provided for as a separate subclass or not, are classified herein.
SEE OR SEARCH THIS CLASS, SUBCLASS:
150, for cascaded vacuum tube amplifiers with amplifier devices having different characteristics (both amplifying devices being of the same general type).
299+, for transistor amplifiers including combined diverse type semiconductors.
310, for plural cascaded stage transistor amplifiers including transistors having different characteristics.
