(under the class definition) Subject matter including means for modulating the signal, which is usually D.C.. or low frequency A.C. amplifying means, and means to restore the original signal, eliminating any carrier frequency components.
(1) Note. The means for eliminating the carrier need not be specifically claimed to be classified in this class if such means are disclosed. As for example, where a demodulator is claimed alone, and a filter means to eliminate the carrier is disclosed the filter need not be claimed for classification herein. The claimed demodulator will be assumed to include the filter in such cases.
(2) Note. Where the modulator and demodulator are of the chopper type see the search notes below.
(3) Note. Including in the "means for modulating the signal" are chopper means to convert the signal to pulsating direct current or alternating current.
SEE OR SEARCH THIS CLASS, SUBCLASS:
7, for amplifiers having a capacitive type amplifying device including those which modulate and demodulate the signal.
8, for amplifiers having saturable reactor type amplifying devices including those which modulate and demodulate the signal. 9, for modulator and demodulator of the chopper type.
SEE OR SEARCH CLASS
324, Electricity: Measuring and Testing,
118, for measuring systems involving modulation-demodulation.
329, Demodulators, appropriate subclasses, for demodulator circuits.
332, Modulators, appropriate subclasses, for modulator circuits.
