26 TAPE RECORDERS, TAPES AND DISCS OF MAGNETIC AND THERMOSENSITIVE NATURE FOR RECORDING SOUNDS OTHER THAN MUSICAL SOUNDS; CONTROL AND TEST EQUIPMENT-NAMELY, SIGNAL LEVEL METERS, BALANCE MEASURING UNITS, CALIBRATED RECEIVERS, CRYSTAL MARKERS, DETECTORS, FAULT LOCATION SETS, FREQUENCY INDICATORS, GRATICULES, GROUP DELAY MEASURING UNITS, INSERT TESTERS, LEVEL INDICATORS, METER UNITS, MONITORS, OSCILLATORS, PULSE TESTING EQUIPMENT, RF PROBES, WAVE FORM IMJECTION AND EXTRACTION UNIT, WOBBULATORS