arrangement for controlling the uebertragungszeit of signals between a ground station and a communications satellites

摘要

This arrangement includes a variable delay circuit through which a color television signal is propagated prior to transmission to a communication satellite. The television signal is received from the satellite at the transmitting station. The color subcarrier is extracted from the received television signal and also from the original television signal. Both of the extracted color subcarriers are translated to the same frequency disposed above the frequency of the television signal. The translated subcarrier extracted from the received television signal is propagated through the delay circuit with the original television signal. At the output of the delay circuit this latter subcarrier is extracted and applied to a phase comparator for comparison with the translated subcarrier extracted from the original television signal. A control signal is produced proportional to the phase difference between the two compared translated subcarriers. The control signal controls the delay of the delay circuit to maintain the compared translated subcarriers in a predetermined phase relationship to compensate for variable transmission time delay to the satellite.