A Solid-State Converter for Measurement of Aircraft Noise and Sonic Boom

A solid-state converter, used in a system of instrumentation for measuring aircraft noise and sonic boom, features a dualgate FET mixer and an output stage designed for compatibility with a zero drive amplifier of MB Electronics, Inc. With a half-inch condenser microphone the converter itself has an operating frequency range from dc-28 kHz (-3 dB), dynamic range of 72 dB, and noise floor of 50 dB in the band 22.4 Hz-22.4 kHz; the system requires no impedance matching networks and is insensitive to cable length up to at least 3000 ft.