AN/SRD-L4 BEARING TESTS AND NONROTATING SPACED LOOP DIRECTION FINDER DEVELOPMENT.

Abstract : A demonstration of the AN/SRD-14 direction finder was carried out. Bearing and sense performance data over the l00 kc to 4 mc range were obtained with the result that =5 deg error calibration curves were obtained for 90% of the frequencies tested. Direct sense was observed from 0.2 to 2 mc above which sense was reversed. Modification of the sense antenna circuits is indicated. Modification and testing of the nonrotating spaced loop D/F system showed that =5 deg error performance was achieved without sense reversal from 2 - 30mc. A two-mc range from 25 - 27 mc encompassing the series resonance of the antennas showed degraded performance and indicates the need of reducing antenna size to shift the resonance out of the operating range. Bearing sensitivity of the twin and goniometer channels was equal within =2 db. Progress in developing methods of using the HP5100 - 5110A synthesizer for rapid programmed tuning of a twin channel receiver is described. Operation of the synthesizer with the Racal RA. 153 and Intercept Research IR-3 receivers is described. (Author)