Demodulation system regenerating carrier waves phase synchronized with corresponding carrier wave components in horizontal synchronizing pulse modulated carrier waves

Claim 2

A receiver regenerating a carrier wave synchronized with a carrier wave component related to a received carrier wave overmodulated by a composite signal containing preselected synchronizing time periods in a partially suppressed carrier vestigial sideband television transmission system, comprising: a receiving source for said carrier wave over-modulated by said composite signal and containing said preselected synchronizing time periods repeated at a preassigned rate; a demodulator supplied at one input terminal with one portion of said received signal over-modulated carrier wave; a load connected to an output terminal of said modulator; sampling means translating a second portion of said received signal over-modulated carrier wave into a train of carrier wave bursts during said preselected synchronizing time periods; frequency selective means utilizing one portion of said carrier wave bursts to regenerate a carrier wave corresponding to a carrier wave component related to said received signal overmodulated carrier wave during said preselected synchronizing time periods; automatic phase control means responsive to a second portion of said carrier wave bursts and one portion of said regenerated carrier wave for supplying said last-mentioned regenerated carrier wave one portion phase synchronized with said carrier wave component to a second input of said demodulator to demodulate said received signal over-modulated carrier wave to detect said modulating composite signal at said load; and pulse producing means coupled to said source and thereby responsive to a third portion of said received signal overmodulated carrier wave and coupled to a second portion of said regenerated carrier wave derived from said frequency selective means for producing a train of further pulses having a repetition time rate coincident with said preassigned repetition time rate of said preselected synchronizing time periods to activate said sampling means to synchronize said carrier wave bursts with said last-mentioned periods.

Claim 3

The receiver according to claim 1 in which said sampling means produces said train of carrier wave bursts having unwanted upper and lower sidebands and said frequency selective means includes a narrow pass-band crystal filter for attenuating said sidebands to regenerate said carrier wave corresponding to said carrier wave component related to said received signal over-modulated carrier wave.

Claim 4

The receiver according to claim 2 in which said further pulse producing means consists of: first envelope detecting means energized by said third portion of said received signal over-modulated carrier wave and said second portion of said regenerated carrier wave, both latter waves having the same polarity, for producing a train of first envelopes representing the addition of both said latter waves and synchronized with said preselected synchronizing time periods contained in said received signal over-modulated carrier wave; second envelope detecting means activated by a third portion of said regenerated carrier wave having a polarity opposite to said one polarity of said third portion of said received Signal over-modulated carrier wave for producing a train of second envelopes having said opposite polarity to be subtracted from said first envelopes to produce a train of composite envelopes to compensate for changes in the level of said regenerated carrier wave relative to a predetermined level in the output of said crystal filter due to an interruption of said regenerated carrier wave in said crystal filter output; and additional pulse producing means stimulated by said composite pulse train for producing said further pulse train to activate said sampling means.

Claim 5

The receiver according to claim 3 in which said additional pulse producing means contains clamping circuit means energized by said train of composite pulses for equalizing tip ends thereof to provide a train of other pulses synchronized with said preselected synchronizing time periods in said third portion of said received signal over-modulated carrier wave.

Claim 6

The receiver according to claim 4 in which said additional pulse producing means includes slicer circuit means for cutting off said equalized tip ends of said other pulses at a predetermined level to provide a train of equalized cut-off tip pulses synchronized with said preselected synchronizing time periods in said third portion of said received signal over-modulated carrier wave.

Claim 7

The receiver according to claim 5 in which said additional pulse producing means embodies differentiator circuit means activated by said train of equalized cut-off tip ends for providing a train of oppositely poled spiked pulses synchronized with said preselected synchronizing time periods in said third portion of said received signal over-modulated carrier wave.

Claim 8

The receiver according to claim 6 in which said additional pulse producing means includes multivibrator circuit means energized by said train of spiked pulses to provide said train of further pulses to activate said sampling means.

Claim 9

The receiver according to claim 7 in which said preselected synchronizing time periods comprise horizontal synchronizing time periods.

Claim 10

A receiver regenerating a carrier wave synchronized with a carrier component related to a received carrier wave over-modulated by a composite signal containing horizontal synchronizing time periods in a partially suppressed carrier vestigial sideband television transmission system, comprising: a receiving source for said carrier wave over-modulated by said composite signal and containing said horizontal synchronizing time periods repeated at a preassigned time rate; a demodulator having two input terminals and an output terminal; a load connected to said modulator output terminal; first hybrid coil means dividing said received signal over-modulated carrier wave into first and second portions of which said first portion is applied to one of said demodulator two input terminals; second hybrid coil means dividing said first hybrid coil means second portion of said received signal over-modulated carrier wave into two further portions thereof; sampling means translating one of said two further portions of said received signal over-modulated carrier wave at said second hybrid coil means into a train of carrier wave bursts, each including unwanted upper and lower sidebands relative to a predetermined frequency; third hybrid coil means dividing said train of carrier wave bursts into two portions; frequency selective means utilizing one of said two portions of said carrier wave burst train at said third hybrid coil means to regenerate a constant level carrier wave having said predetermined frequency and corresponding to a carrier wave component related to said received signal over-modulated carrier wave during said horizontal synchronizing time periods; fourth hybrid coil means dividing said regenerated carrier wave into two portions; automatic phase control means responsive to the other of said two portions of said third hybrid coil means carrier wave burst train and one of said two portioNs of said fourth hybrid coil means regenerated carrier wave for supplying said last-mentioned regenerated carrier wave one portion phase synchronized with said carrier wave component to a second of said demodulator inputs to demodulate said received signal over-modulated carrier wave to detect said composite signal at said load; and pulse producing circuit means activated by the other of said two further portions of said received signal over-modulated carrier wave at said second hybrid coil means and the other of said regenerated carrier wave two portions at said fourth hybrid coil means for producing a train of other pulses to synchronize said carrier burst train with said horizontal synchronizing time periods, including: fifth hybrid coil means dividing said regenerated carrier wave other portion at said fifth hybrid coil means into two additional portions thereof; sixth hybrid coil means responsive to the other of said second hybrid coil means two portions of said received signal over-modulated carrier wave having said carrier wave component thereof in one polarity and one of said two additional regenerated wave portions at said fifth hybrid coil means with a polarity the same as said last-mentioned one polarity for adding said last-mentioned other and one additional wave portions to provide a train of composite waveforms during said horizontal synchronizing time periods; first envelope detecting means activated by said composite waveform train to provide a train of composite envelopes synchronized with said horizontal synchronizing time periods; second envelope detecting means activated by the other of said two additional portions in a phase opposite to the phase of said one additional portion at said fifth hybrid coil means to provide a train of envelopes of said other additional portions in a phase opposite to the phase of said train of composite envelopes whereby said other additional envelope train is subtracted from said composite envelope train to provide a train of difference envelopes in response to variations in the level of said regenerated carrier wave at said fourth hybrid coil means and in synchronism with said horizontal synchronizing time periods; and multivibrator means energized by said difference pulse train for providing said train of other pulses synchronized with said horizontal synchronizing time periods to activate said sampling means to synchronize said carrier wave bursts with said last-mentioned periods.

Claim 11

A receiver regenerating a carrier wave synchronized with a carrier component related to a received carrier wave over-modulated by a composite signal containing horizontal synchronizing time periods in a partially suppressed carrier vestigial sideband television transmission system, comprising: a receiving source for said carrier wave over-modulated by said composite signal and containing said horizontal synchronizing time periods repeated at a preassigned time rate; a demodulator having two input terminals and an output terminal; a load connected to said modulator output terminal; first hybrid coil means dividing said received signal over-modulated carrier wave into first and second portions of which said first portion is applied to one of said demodulator two input terminals; second hybrid coil means dividing said first hybrid coil means second portion of said received signal over-modulated carrier wave into two further portions thereof; sampling means translating one of said two further portions of said received signal over-modulated carrier wave at said second hybrid coil means into a train of carrier wave bursts, each including unwanted upper and lower sidebands relative to a predetermined frequency; third hybrid coil means dividing said train of carrier wave bursts into two portions; frequency selective means utilizing one of said two portions of said carrier wave burst train at said third hybrid coil means to regenerate a constant level carrier wave having said predetermined frequency and corresponding to a carrier wave component related to said received signal over-modulated carrier wave during said horizontal synchronizing time periods; fourth hybrid coil means dividing said regenerated carrier wave into two portions; automatic phase control means responsive to the other of said two portions of said third hybrid coil means carrier wave burst train and one of said two portioNs of said fourth hybrid coil means regenerated carrier wave for supplying said last-mentioned regenerated carrier wave one portion phase synchronized with said carrier wave component to a second of said demodulator inputs to demodulate said received signal over-modulated carrier wave to detect said composite signal at said load; and pulse producing circuit means activated by the other of said two further portions of said received signal over-modulated carrier wave at said second hybrid coil means and the other of said regenerated carrier wave two portions at said fourth hybrid coil means for producing a train of other pulses to synchronize said carrier burst train with said horizontal synchronizing time periods, including: fifth hybrid coil means dividing said regenerated carrier wave other portion at said fifth hybrid coil means into two additional portions thereof; sixth hybrid coil means responsive to the other of said second hybrid coil means two portions of said received signal over-modulated carrier wave having said carrier wave component thereof in one polarity and one of said two additional regenerated wave portions at said fifth hybrid coil means with a polarity the same as said last-mentioned one polarity for adding said last-mentioned other and one additional wave portions to provide a train of composite waveforms during said horizontal synchronizing time periods; first envelope detecting means activated by said composite waveform train to provide a train of composite envelopes synchronized with said horizontal synchronizing time periods; second envelope detecting means activated by the other of said two additional portions in a phase opposite to the phase of said one additional portion at said fifth hybrid coil means to provide a train of envelopes of said other additional portions in a phase opposite to the phase of said train of composite envelopes whereby said other additional envelope train is subtracted from said composite envelope train to provide a train of difference envelopes in response to variations in the level of said regenerated carrier wave at said fourth hybrid coil means and in synchronism with said horizontal synchronizing time periods; and multivibrator means energized by said difference pulse train for providing said train of other pulses synchronized with said horizontal synchronizing time periods to activate said sampling means to synchronize said carrier wave bursts with said last-mentioned periods.

Claim 12

The receiver according to claim 9 in which said multivibrator means includes: clamping circuit means energized by said train of difference pulses for equalizing tip ends thereof to provide a train of equalized pulses synchronized with said horizontal synchronizing time periods in said third portion of said received signal over-modulated carrier waves at said sixth hybrid coil means; slicer circuit means for cutting off said equalized tips of said train of equalized pulses at a predetermined level to provide a train of equalized cut-off tip pulses synchronized with said last-mentioned horizontal synchronizing time periods; differentiator circuit means activated by said train of equalized cut-off tip pulses to provide a train of oppositely poled spiked pulses synchronized with said last-mentioned horizontal synchronizing time periods; and a multivibrator circuit energized by said train of spiked pulses for providing said train of other pulses synchronized with said horizontal synchronizing time periods to activate said sampling means to synchronize said carrier wave bursts with said last-mentioned time periods.