Vestigial sideband transmission

Claim 1

A SIGNAL TRANSMISSION SYSTEM COMPRISING A TRANSMITTING TERMINAL INCLUDING MEANS FOR GENERATING SIGNALS OCCUPYING A VOICEBAND FREQUENCY RANGE, MEANS FOR MODULATING SAID VOICEBAND SIGNALS ON A HIGH FREQUENCY CARRIER, DOUBLE SIDEBAND FILTER MEANS FOR FILTERING THE MODULATED SIGNALS, LEVEL CONTROL MEANS FOR REGULATING AMPLITUDES OF THE FILTERED SIGNALS, TRANSFER MODULATOR MEANS FOR MODULATING THE LEVEL CONTROLLED SIGNALS UPON A LOW FREQUENCY CARRIER, AND A SINGLE SIDEBAND VESTIGIAL FILTER CONNECTED TO THE LAST NAMED MODULATOR MEANS FOR PRODUCING A SINGLE SIDEBAND VESTIGIAL WAVE ENVELOPE, A RECEIVING TERMINAL, AND A NARROW BAND SIGNAL TRANSMISSION LINE CONNECTING THE TRANSMITTING AND RECEIVING TERMINALS; SAID RECEIVING TERMINAL COMPRISING AN EQUALIZER FOR REMOVING AMPLITUDE AND PHASE DISTORTION COMPONENTS INTRODUCED IN SAID ENVELOPE DURING TRANSMISSION OF THE SAME TO SAID RECEIVING TERMINAL FROM THE TRANSMITTING TERMINAL, MEANS FOR MODULATING SAID ENVELOPE ON A HIGH FREQUENCY CARRIER, BAND PASS FILTER MEANS FOR FILTERING THE TRANSFERRED ENVELOPE, LEVEL CONTROL MEANS FOR STABILIZING ATTENUATION VARIATIONS IN THE FILTERED ENVELOPE, MEANS FOR DETECTING THE LEVEL CONTROLLED ENVELOPE TO PRODUCE UNIPOLAR LOW FREQUENCY SIGNALS, LOW PASS FILTER MEANS FOR FILTERING THE DETECTED SIGNALS, AND MEANS FOR NEUTRALIZING SIGNAL DISTORTION OF THE DETECTED SIGNALS, THE LAST NAMED MEANS COMPRISING AN INVERTER AND MODULATOR FOR INVERTING POLARITY OF THE FILTERED DETECTED SIGNALS AND FOR MODULATING THE INVERTED SIGNALS UPON A HIGH FREQUENCY CARRIER TO PRODUCE A DISTORTED CARRIER ENVELOPE, A VESTIGIAL FILTER FOR NEUTRALIZING ENVELOPE DISTORTION IN THE INVERTED ENVELOPE TO PRODUCE A VESTIGIAL ENVELOPE FREE OF QUADRATURE DISTORTION, A DETECTOR OF SAID VESTIGIAL ENVELOPE, AND A VOICEBAND FREQUENCY FILTER FOR THE DETECTED VESTIGIAL ENVELOPE TO PRODUCE SUBSTANTIALLY DISTORTION FREE VOICEBAND SIGNALS CORRESPONDING TO THE PHOTOELECTRICALLY GENERATED SIGNALS.