Abstract: A coupler utilizing a repeater. Dedicated transmit and receive lines interconnect transmitters and receivers with the data bus and, receive lines from other hybrid lines are optically isolated by approximately 23 db from the receiver in the repeater by first and second mixers, isolation of the receiver from signals originating from other couplers preventing race conditions. Power equalization is inherent since signals from other couplers are received at nearly the same signal level as signals from local transmitters, repeater transmitter levels being adjustable for compensation for any small difference occurring due to coupler power splitting and line losses.