TELEGRAPHY RECEIVER FOR HARMONIC TELEGRAPHY

摘要

A multichannel telegraphy receiver for harmonic telegraphy where for each channel different levels of an input signal are characterized by different frequencies of the carrier. The receiver comprises for each receiver channel a discriminator including a digital counter, a continuously active counting pulse generator coupled to the input of the counter and a decoder connected to the counter and having an output circuit formed by a register. The register has a separate output for each of the different levels of the input signal. A zero-crossing detector in the input circuit of the receiver channel provides reset pulses to the counter and input pulses for the register.