U.S. Philips Corporation

Ulf H Buhse

Henning Schwarz

Hans-Jurgen Kuhn

In a multi-standard television receiver in which a picture signal contained in a television signal and modulated on a picture carrier is converted to a picture signal intermediate frequency, and a stereo sound signal or two-tone signal contained in the television signal and modulated on two sound carriers is converted to two first sound signal intermediate frequencies, it is ensured for possibly simple filtering of the sound signals, also at different frequency spacings between the picture carrier and the sound carriers, that two sound signal filters (8, 9) having a fixed, predetermined filter central frequency are provided for filtering the stereo sound signal, and that frequency shift circuitry (6) is provided which, in dependence upon the frequency spacing between the picture carrier of the television signal and its sound carriers, shifts the picture carrier contained in the picture signal converted to the IF position to such a frequency that the sound IF signals of the first sound intermediate frequencies mixed with this shifted picture carrier occur at two second sound signal intermediate frequencies which are filtered by the sound IF filters (8, 9).

Multi-standard television receiver

A processing section for a television receiver for processing stereo/dual sound signals having a first sound carrier modulated by a first sound signal, and a second sound carrier modulated both by a second sound signal and by a pilot signal which, in turn, is modulated by a stereo/dual sound identifying signal. The processing section does not require a reference frequency from the synchronizing or intermediate frequency portion of the television receiver for recovering the pilot signal, but, rather, uses the pilot signal to control an oscillator in a phase-locked loop which loop is used to generate a signal for down-converting the frequency range of at least the modulated second sound carrier thereby obviating the need for expensive, precision filtering components.

Television receiver incorporating a processing section for processing

Circuit arrangement for receiving two modulating signals, more specifically for television, particularly for the transmission of stereo signals or dual channel independent sound signals, each of the two modulating signal being conveyed through respective variable amplifiers, the gain of the amplifiers being adjustable in the opposite current directions for an optimum dematrixing of the stereo signal and being switchable by a factor of 2 for the reception of dual channel independent sound signals.

Circuit arrangement for receiving two modulating signals, more

The invention relates to a circuit for use in a receiver which can receive two-tone/stereo signals. This circuit is intended to make a choice between mono or stereo reproduction of signal A or of signal B and vice versa. The circuit comprises two bistable multivibrator circuits which are controlled by a common, user-operable switch and by characteristic signals which are derived from the characteristic frequencies relevant to the different types of programs. The control is such that when the switch is operated only one bistable multivibrator circuit can be changed over (namely the bistable multivibrator circuit associated with the relevant characteristic frequency received.) A logic circuit which is controlled by the bistable multivibrator circuit as well as by the characteristic signals operates a change-over switch for switching to the desired reproduction.

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Kollmar, Germany

Ulf H Buhse