Abstract: A bus buffer conditions and amplifies bi-directional electrical signals on a line carrying MIL-STD 1553 bi-polar signals. The device includes a receiver with a threshold detector, a signal conditioner including a retiming circuit and an amplifying transmitter. The signal conditioner receives filtered bi-polar signal output from the receiver and transforms the signal into separate uni-polar digital outputs. The signal conditioner includes means for increasing the positive voltage state period of each uni-polar output voltage state until the beginning of the next output voltage state to eliminate an effective null bus period during a signal transmission. A timing circuit includes a clock and logic circuitry which retimes and combines the uni-polar signals to create a bi-polar digital output having retimed zero-crossing points which is then transmitted out to a second bus. Two bus buffers are connected between the first and second buses in reverse orientation to provide bidirectional capability.