Noise canceler for keying pulse in CATV converter

摘要

A noise canceler for use in a CATV converter includes a keying pulse processing circuit for removing a noise signal from a keying signal. The keying pulse processing circuit includes a canceling signal generator for generating a noise canceling pulse signal, a delaying circuit for delaying the keying signal to produce a delayed signal, and a logic circuit including an AND gate for producing a noise canceled signal which is obtained by taking a logical product of the canceling pulse signal and the delayed signal. Since the noise pulse has a sufficiently small width when compared with the pulse widths of the keying signal and noise removing signal, the noise pulse is removed to obtain a noise canceled signal.