An Experimental 600-Foot Sonic Delay Line for the Navy Space Surveillance System

Since the Navy Space Surveillance System operates continuously, there is a large yearly expenditure for recording paper. It was suggested that the recorders be turned on only during a satellite "pass" providing enough signal delay could be introduced so that the recorders could overcome their starting inertia. The requirement for delaying the composite (IRIG) FM telemetering signals from a Space Surveillance site by one-half second was fulfilled by converting the phone line frequencies into sound, which is then transmitted through a pipe long enough to provide the desired delay, and then reconverted into electrical signals for transmission over the line. The results of the experiment were satisfactory.