NEGATIVE RESISTANCE OR REACTANCE NETWORKS OF THE ACTIVETYPE:
(under the class definition) Systems including active elements for producing, across at least two of the system terminals, a negative resistance and/or an inductance or capacitance which may be positive or negative.
(1) Note. This subclass does not include dynamoelectric machine systems which are used as a reactance element.
SEE OR SEARCH CLASS
307, Electrical Transmission or Interconnection Systems,
401+, for nonlinear reactance systems which may exhibit negative resistance characteristics.
323, Electricity: Power Supply or Regulation Systems,
212, 219 for phase shift systems. 327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, appropriate subclasses for miscellaneous circuits utilizing negative resistance devices.
75+, for feedback amplifiers of the vacuum, tube type, particularly subclasses 82, 93, 101, 104, and 112 for positive feedback amplifiers; and subclasses 291+ for transistor feedback amplifiers.
86+, for magnetron-type oscillators which may utilize negative resistance effects; subclass 115 for transistor oscillators of the negative resistance type; subclasses 126+ for oscillators utilizing the negative resistance characteristic of a gaseous space discharge; and subclasses 132+ for negative resistance or negative transconductance oscillators in general. Subclasses 1+ of Class 331 provide for automatic frequency stabilized oscillators many of which utilize adjustable reactance tubes, indented subclass 36 provides for particular frequency control means (e.g., reactance tubes, saturable inductors, etc.); and subclass 180 provides for oscillators in general including frequency adjusting means of the reactance tube type.
332, Modulators, particularly
140, and 142+ for reactance tubes in frequency modulators, subclasses 147+ for reactance tubes in phase modulators, and subclass 175 for reactance tubes in amplitude modulators.
14+, for tuners utilizing reactance tube networks.