Pre-Launch Testing of High Frequency Digital Data

This paper discusses the techniques used in testing digital signals of a subsystem interface at a distance of 1200 feet. It shows the development of a hardline system which overcomes the problems of propagation delay and poor cable response to high frequency pulse signals. The system evolves as a three piece unit including a cable driver located at the space vehicle, a remote unit located at the gantry and a control and readout unit located at the blockhouse.