B K

[FILTER CHASSIS,] FILTER SETS, [ FREQUENCY TRANSFORMERS, ] LEVEL RECORDERS, MICROPHONE AMPLIFIERS, STANDING WAVE APPARATUS, MICROPHONES, MICROPHONE CARTRIDGES, [ CABLES AND STANDS, ] MICROPHONE SELECTORS, [ MICROPHONE SELECTOR INVERTERS,] ACOUSTIC COUPLERS, [ CATHODE FOLLOWERS AUTOMATIC REVERBERATION SWITCHES, VHF CONVERTERS, ] VIBRATION PICKUP PREAMPLIFIERS

SONIC, AUDIO AND LOW FREQUENCY SIGNAL GENERATORS AND CONTROL SYSTEMS, [ IMPEDANCE, DEVIATION AND ] FREQUENCY AND DISTORTION MEASURING BRIDGES AND ACCESSORIES THEREFOR, STRAIN GAUGE APPARATUS, BALANCING UNITS, [ BALANCING RESISTORS AND CONDENSERS, ] BRIDGE SUPPLIES AND BRIDGE SWITCHES, ACCELEROMETERS, ACCELEROMETER PREAMPLIFIERS, AUDIO FREQUENCY SPECTROMETERS, AUDIO FREQUENCY [ RESPONSIVE AND ] SPECTRUM RECORDERS, AUDIO FREQUENCY TRANSFORMERS, R;M;S; ELECTRONIC VOLTMETERS, AUDIO FREQUENCY VOLTMETERS, WIDE RANGE VOLTMETERS, [ HETERODYNE VOLTMETERS, MEGOHMMETERS AND HIGH VOLTAGE ACCESSORIES THEREFOR, ] ARTIFICIAL EARS, MICROPHONE CALIBRATION EQUIPMENTD, ARTIFICIAL NOISE [ SOURCES, ] HEARING AID TEST CHAMBERS, ACCELEROMETER CALIBRATION EXCITERS, VOLTMETEERS, POTENTIOMETERS, BEAT FREQUENCY OSCILLATORS, [ COMPLEX MODULUS APPARATUS FOR DETERMINATION OF COMPLEX MODULUS OF ELASTICITY AND LOSS FACTOR OF SOLID MATERIALS, COMPLEX MODULUS RECORDERS, ] CONSTANT SOUL PRESSURE SOURCES, PISTONPHONES, POLAR RECORDERS, POLAR TURNTABLES, ELECTROSTATIC ACTUATORS, FREQUENCY RESPONSE TRACERS, AUTOMATIC VILBRATION EXCITER CONTROLS, SURFACE ROUGHNESS MEASURING METERS, [ CONTROL PANELS, ] AND ACCESSORIES FOR THE FOREGOING INSTRUMENTS