Audio IF filter circuit for TV receiver - has tuner outputs coupled to one side of audio sawtooth filter input terminals

摘要

The tuner (1) outputs (IF1,2) are coupled to the side of an anchor sawtooth filter (4) input terminals (4a,b). Simultaneously the output (IF1) is coupled to a transistor (Q1) with an earthed filter, at whose base a control signal (Va) is tapped. The other side ofthe input terminal fo the filter, includes diodes (D1,2) and is coupled to a current supply (Vs). A side of the filter output terminals is coupled to the diodes via a capacitor (C3) and to the minut input terminal of the IFF demodulator (6). It is also linked to the collection of a second transistor (Q") with the earthed filter. USE/ADVANTAGE - For multo-system TV receiver, audio and video sawtooth filter, and audit RF demodulator. Reduced tuner load in a low-cost design.