Reduction of pulse interference in television. Use of cathode-coupled amplifier pairs in black-spotter circuits

A method of pulse interference reduction known as ¿black-spotting,¿ which has been used in television receivers designed for reception of positive-modulation (e.g. current British 405/50 standard) transmission, is discussed. In a special case the method is equivalent to simple limiting, but in general may be considerably more effective. A brief review of known circuit technique is followed by a more detailed description of examples chosen to exhibit the particular suitability of the cathode-coupled pair type amplifier as a basis for improved circuit arrangements.