Phonograph record profile tracer

摘要: Phonograph record profile testing apparatus comprises A. A TURNTABLE SUBSTANTIALLY UNDERSIZED RELATIVE TO THE RECORD OVERALL DIAMETER FOR SUPPORTING WITH OPPOSITE SIDES THEREOF EXPOSED, AND B. PAIR OF TRANSDUCERS INCLUDING SENSORS AT LOCATIONS SPACED RECEIVE SUPPORTED THEREBETWEEN, SIMULTANEOUSLY ENGAGE PRODUCE ELECTRICAL SIGNALS WHICH VARY IN RESPONSE MOVEMENT SURFACE PORTIONS ENGAGED BY GENERALLY NORMAL PLANE RECORD. The sensors may have engagement tips at locations spaced apart along a direction which is generally normal to the plane; arm structure carries transducers such location; and means provided displace that carry radially across record.