Abstract: A digital data system which includes a passive coupler from a transmission line and a clock recovery device and a sample pulse generator coupled with the clock recovery device to generate sample pulses in relation to the recovered clock signal and a comparator device for comparing the sample pulse signal with the signal received from the passive coupler.

Abstract: Digitial audio data transmission technique which utilizes time division multiplexed messages, for transmitting information from point A to point B, while having intermediate points therebetween for augmenting the information without completely demodulating and remodulating the entire signal at each intermediate point. The technique comprises generating a clock signal having a plurality of pulses therein which are separated by a plurality of expansion regions. The expansion regions are utilized for containing the data information and the presence or absence of a pulse in the expansion region represents the message. Initially, the clock information and a message information is transmitted from point A along with a portion of the transmission containing clock information only and no message information.