Full duplex two wire DC telegraphic system - has terminal circuit with resistors forming octagon with transmitter and receiver across diagonals

摘要

The terminal circuit, for full-duplex two-wire dc telegraphic systems, consists of eight resistors connected into a closed loop so that each resistor forms one side of an octagon. The transmitter is located across one large diagonal and the receiver across the second large diagonal of this octagon. The transmission lines are connected to the four remaining corners of the cotogon. The resistors (R) all have the same value which can be chosen regardless of the output impedence of the transmitter, the input impedence of the receiver and the impedence of the transmission line.