FM-Multiplexsystem zur UEbertragung stereophoner NF-Signale

1,151,662. Radio signalling; pick-ups. GENERAL ELECTRIC CO. 20 Nov., 1967 [22 Dec., 1966], No. 52636/67. Headings H4J and H4L. To enable stereophonic gramophone records to be reproduced via a stereophonic F.M. radio receiver, the pick-up element is arranged to produce L + R and L - R signals from which a normal stereophonic radio signal is generated by conventional means. Pick-up element.-A piezo-resistive element 20 is cantilever-mounted and its free end displaced by forces F 1 , F 2 from a stylus. Two parallel, longitudinal strips 21, 22, which comprise low resistivity portions of the crystal, are connected at one end by an element 25. The resistances of the strips normally are equal but change when undergoing strain. The force F 1 corresponding to the L signals affects both strips equally, but the force F 2 (the R signal) effects the strips oppositely.