DATA DISPLAY APPARATUS AND PARTS THEREOF; RADAR DISPLAY APPARATUS; ANTENNA COUPLERS; AND PARTS OF ALL THE FOREGOING; ELECTRONIC AMPLIFIERS; ANTENNAS; A-C TO D-C AND D-C TO A-C CONVERTERS; ELECTRONIC COUPLERS; SIGNAL GENERATORS; MICRO-MINIATURE ELECTRONIC CIRCUITS; PHASE SHIFTERS; POWER SUPPLIES; RADIO TRANSMITTERS AND TRANSPONDERS; MICROWAVE DIRECTIONAL COUPLERS; ELECTRIC TRANSMISSION LINES; FIBER OPTICS; RADAR AND RADAR APPARATUS; FREQUENCY ANALYZERS; NAVIGATIONAL APPARATUS AND INSTRUMENTS F...