US PATENT SUBCLASS 334 / 78
VARIABLE CAPACITOR TUNED

Current as of: June, 1999
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334 /   HD   TUNERS

78VARIABLE CAPACITOR TUNED {6}
79  DF  .~> Straight-line frequency type
80  DF  .~> With variable spacing between plates
81  DF  .~> Rectilinearly sliding plates
82  DF  .~> With particular shape and/or arrangement of plates
83  DF  .~> Gang-operated capacitors
84  DF  .~> Capacitor drive means

DEFINITION

Classification: 334/78

(under the class definition) Subject matter wherein a parallel tuned circuit consists of an inductor of fixed inductance value and a tuning capacitor, the capacitance value of which may be varied over a given range in order to tune the circuit over a range or band of frequencies.

(1) Note. To be properly classified in this subclass, the capacitor must be of a variable type. If fixed capacitors are switched into and out of a tuned circuit to thereby vary

the frequency, classification is not in this subclass but in subclass 55 above.

SEE OR SEARCH THIS CLASS, SUBCLASS:

11+, for voltage and/or current responsive tuning elements which may be capacitors.

45, for distributed parameter type tuners which use a lumped capacitor which may be variable.

51, for turret tuners of the switching drum type having vernier tuning means which may be a variable capacitor. 55, for tuned circuits using fixed capacitors switched in or out of the circuit.

58, for switched inductor structures provided with vernier variable capacitor means.

64, for series tuned circuits which may use a variable capacitor.

65+, for tuners where both the inductor and capacitor are variable.

SEE OR SEARCH CLASS

74, Machine Element or Mechanism,

10+, for drive means for a shaft operated radio tuner which may be operating a variable capacitor.

331, Oscillators,

167+, for L-C type oscillators generally. See also the Search Notes under this subclass for L-C type oscillator circuits generally.

361, Electricity: Electrical Systems and Devices,

268+, for a transformer or inductor combined with a capacitor, and subclasses 271+ for capacitors, per se, particularly indented subclasses 277+ for variable capacitors. See also the Search Notes under this subclass for a complete field of search as to capacitors.