Mono, stereo or two-tone switching method in TV receiver - switching to stereo reproduction when specified relation is max. and equal to preset threshold value

摘要

A device determines a value (A) of a pilot carrier (PT) and another one determines the characteristic value (B) of a stereo-carrier (ST) and/or a characteristic value (C) of a two-tone carrier (ZT). The stereo-reproduction is switched over when the ratio of the pilot carrier value and the stereo carrier value is max. equal to a preset threshold value (E). Pref. the two-tone reproduction is switched over when the ratio of the pilot carrier value to the two-tone carrier value equals to the preset threshold value. The mono-reproduction is switched over when the above mentioned ratios are higher than the preset threshold value. USE/ADVANTAGE - Reproduction mode switching in TV receiver, with improved characteristic even in bad reception conditions, or on interference.