An experimental 600-foot electrosonic delay line for the navy space surveillance system

For many types of data transfer systems it is desirable that the data be delayed long enough so that the system is ready for the data. In the present Space Surveillance system it is desirable to delay data until the recorder is up to speed. The requirement for delaying the composite Inter-Range Instrumentation Group (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. The delayed output is essentially distortionless.