Portland, OR -- Elwood "Woody" Norris pointed a metal frequency emitter at one of perhaps 30 people who had come to see his invention. The emitter, an aluminum square, was hooked up by a wire to a CD ...
These days almost everyone has either flown a drone or listened to the nasty whining sound they produce. Although small drones (up to 20kg) are about 40 decibels quieter than conventional civil ...
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