Abstract: Data transmission system for transmitting data on a cable and in two directions between two terminal stations (LTE1/2) and via repeater stations (REP1/2). Each terminal station has a sender/receiver (CODEC) and each repeater station has a receiver/sender (CODEC1/2) for each direction. Each station is able to convert predetermined 5-bit data words and auxiliary information into predetermined 6-bit data words and to extract auxiliary information from these 6-bit words. In the case of cable rupture the receiver for one direction in a repeater station is connected to the receiver for the other direction.

Abstract: In a repeater for a communication system a continuously running local oscillator (P) injects a pilot tone into the repeater input, ahead of all the non-linear functions. The repeater may include an input amplifier 1, a re-shaping amplifier 2 and an output amplifier 3. The pilot frequency is unique to the repeater and is sufficiently close to the clock frequency in a digital system or the carrier frequency in an analogue system to allow the pilot to pass through all the repeater filters. The pilot effects a small phase modulation of the carrier or clock. Measurement of the amount of phase modulation and also the pilot amplitude at the receiving terminal indicates degradation or failure of the system performance. The pilot frequency is used to identify the repeater.

Abstract: A supercapacitance element is disclosed having the input signal applied to both the inverting and non-inverting inputs of a single operational amplifier via two respective potentiometers made up of resistors except for the branch between the inverting input and the ungrounded input terminal which is constituted by a capacitor. The amplifier output is resistively connected to the inverting input of the amplifier and capacitively connected to the ungrounded input terminal.