Signal separation networks

In a television receiver having a common detector for producing, at an output, detected video frequency signal components and an intercarrier sound signal having a given frequency, means, having an input terminal, for processing said video frequency signal components;

• means, having an input, for processing said intercarrier sound signal;
• and a bandpass filter, tuned to said intercarrier sound frequency and having an input, and an output coupled to the input of said intercarrier sound signal processing means;
• a network for separating said video and intercarrier sound signal components comprising:
• a first signal path coupled between the output of said detector and the input terminal of said video signal processing means;
• a second signal path coupled in parallel with said first signal path and including a first reactive impedance element of one sign;
• a third signal path, including a second reactive impedance element of an opposite sign, coupled between said second signal path and the input of said bandpass filter;
• and
• a fourth signal path coupled between the junction of said third signal path and the input of said bandpass filter and a point of reference potential and having an impedance which is less than the impedance of said third signal path at said intercarrier sound frequency,
• wherein said first, second, third and fourth signal paths comprise a tuned circuit for attenuating said intercarrier sound signal at said input terminal and
• wherein said first signal path includes a resistive impedance element having a resistance which is substantially equal to four times the sum of the resistive impedances of said third and fourth signal paths.

In a television receiver having a common detector for producing, at an output, detected video frequency signal components and an intercarrier sound signal having a given frequency, means, having an input terminal, for processing said video frequency signal components;

• means, having an input, for processing said intercarrier sound signal;
• and a bandpass filter, tuned to said intercarrier sound frequency and having an input, and an output coupled to the input of said intercarrier sound signal processing means;
• a network for separating said video and intercarrier sound signal components comprising:
• a first signal path coupled between the output of said detector and the input terminal of said video signal processing means;
• a second signal path coupled in parallel with said first signal path and including a first reactive impedance element of one sign;
• a third signal path, including a second reactive impedance element of an opposite sign, coupled between said second signal path and the input of said bandpass filter;
• and
• a fourth signal path coupled between the junction of said third signal path and the input of said bandpass filter and a point of reference potential and having an impedance which is less than the impedance of said third signal path at said intercarrier sound frequency,
• wherein said first, second, third and fourth signal paths comprise a tuned circuit for attenuating said intercarrier sound signal at said input terminal and
• wherein said bandpass filter comprises a ceramic filter.

In a television receiver having a common detector for producing, at an output, detected video frequency signal components and an intercarrier sound signal having a given frequency, means, having an input terminal, for processing said video frequency signal components;

• means, having an input, for processing said intercarrier sound signal;
• and a bandpass filter, tuned to said intercarrier sound frequency and having an input, and an output coupled to the input of said intercarrier sound signal processing means;
• a network for separating said video and intercarrier sound signal components comprising:
• a first signal path coupled between the output of said detector and the input terminal of said video signal processing means;
• a second signal path coupled in parallel with said first signal path and including a first reactive impedance element of one sign;
• a third signal path, including a second reactive impedance element of an opposite sign, coupled between said second signal path and the input of said bandpass filter;
• and
• a fourth signal path coupled between the junction of said third signal path and the input of said bandpass filter and a point of reference potential and having an impedance which is less than the impedance of said third signal path at said intercarrier sound frequency,
• wherein said first, second, third and fourth signal paths comprise a tuned circuit for attenuating said intercarrier sound signal at said input terminal and
• wherein said bandpass filter comprises a parallel LC circuit.

In a television receiver having a common detector for producing, at an output, detected video frequency signal components and an intercarrier sound signal having a given frequency, means, having an input terminal, for processing said video frequency signal components;

• means, having an input, for processing said intercarrier sound signal;
• and a bandpass filter, tuned to said intercarrier sound frequency and having an input, and an output coupled to the input of said intercarrier sound signal processing means;
• a network for separating said video and intercarrier sound signal components comprising:
• first and second parallel signal paths coupled between the output of said detector and the input terminal of said video signal processing means;
• a third signal path, including a reactive impedance element and a resistive impedance element, coupled between said second signal path and a point of reference potential;
• and
• means, independent of said reactive impedance element, for coupling said resistive impedance element of said third signal path in parallel with the input of said bandpass filter,
• wherein said first, second, and third signal paths comprise a tuned circuit for attenuating said intercarrier sound signal at said input terminal.

In a television receiver having a common detector for producing, at an output, detected video frequency signal components and an intercarrier sound signal occupying a given frequency range, means, having an input terminal, for processing said video frequency signal components;

• means, having an input, for processing said intercarrier sound signal;
• and a bandpass filter, tuned to a frequency of said intercarrier sound frequency range, exhibiting a given input impedance, and having an input, and an output coupled to the input of said intercarrier sound signal processing means;
• a network for separating said video and intercarrier sound signal components comprising:
• first and second parallel signal paths coupled between the output of said detector and the input terminal of said video signal processing means;
• a third signal path including a resistive impedance element and an inductive impedance element, coupled between said second signal path and a point of reference potential;
• and
• means, independent of said resistive impedance element, for coupling said inductive impedance element of said third signal path in parallel with the input of said bandpass filter, said inductive impedance element exhibiting an impedance which is less than said given input impedance at the tuned frequency of said bandpass filter,
• wherein said first, second, and third signal paths comprise a tuned circuit for attenuating said intercarrier sound signal at said input terminal and for attenuating signals having frequencies less than said given frequency range at the input of said bandpass filter.