Accession Number : AD0629889
Title : APPLICATION OF PRE-DETECTION AND RECORDING TECHNIQUES TO DATA COLLECTION SYSTEMS.
Descriptive Note : Technical memo.,
Corporate Author : ELECTRONIC DEFENSE LABS SYLVANIA ELECTRONIC SYSTEMS-WEST MOUNTAIN VIEW CALIF
Personal Author(s) : Lucas,Ray D.
Report Date : 30 NOV 1965
Pagination or Media Count : 40
Abstract : The report evaluates pre-detection recording techniques for uncooperative signal acquisition with particular emphasis on the problems associated with wide band, wide dynamic range AM signals. Since the pre-detection recording process is placed in series, between the IF amplifier and the data processing circuits, new sources of noise and distortion are introduced. One of the basic problems is to identify the sources of signal degradation in the pre-detection process. The influence of receiver characteristics on the pre-detection recording process is discussed in Section 3. In Section 4, several techniques for down-conversion of IF signals to a center frequency compatible with a wideband tape recorder are discussed. Section 5 discusses tape recording techniques and Section 6 reviews the relative merits of several up-conversion schemes. The specific problems associated with pre-detection recording of AM signals are discussed in Section 7. Appendix A develops a scheme for a broadband 90-degree phase shifter which is of considerable value to the up-conversion problem, and gives the test results of a breadboard of the phase shifter. Appendix B gives the test results on a commercially available down-converter. Appendix C, written by L. N. Ferguson, discusses the 'care and feeding' of wide band tape recorders.
Descriptors : (*TELEMETERING DATA, DETECTION), (*DETECTION, RECORDING SYSTEMS), MODULATION, PHASE, AMPLITUDE MODULATION, PULSE MODULATION, FREQUENCY, PHASE SHIFT CIRCUITS, TELEMETERING RECEIVERS, TELEMETERING TRANSMITTERS, MAGNETIC TAPE, FREQUENCY, SINGLE SIDEBAND COMMUNICATIONS, AUTOMATIC FREQUENCY CONTROL, AUTOMATIC GAIN CONTROL, INTERMEDIATE FREQUENCIES
Subject Categories : Electricity and Magnetism
Distribution Statement : APPROVED FOR PUBLIC RELEASE