GB603908A - Phonograph pickup - Google Patents

Abstract

603,908. Gramophone pick - ups. FARNSWORTH TELEVISION & RADIO CORPORATION. Nov. 5, 1945, No. 29329. Convention date, July 5. [Class 40 (iv)] A variable-resistance type of gramophone pick-up suitable for either " hill and dale" or " transverse " recordings, consists of a member 11 having an extended flexible portion 15, which carries at its end a stylus, and which has four inlaid strips 20, 21, 22, 23 of electrically resistive material which varies in resistance during compression or tension. During playing of a " hill and dale " record the strips 20, 21 suffer compression at the same moment as strips 22, 23 are in tension, while during playing of a " transverse " record strips 20, 22 are compressed when strips 21, 23 are in tension. The stylus-end of the strips 20, 21, 22, 23 are connected together, and the opposite ends are connected to potentiometers as shown in Fig. 6. The strips 20, 21, 22, 23 are shown in the same relative positions as shown in Fig. 3. When playing " hill and dale" records potentiometercontrols 65 and 79 are set to the extreme left and right positions respectively, i.e. resistances 60 and 62 short-circuited, while potentiometercontrols 80 and 66 are used for controlling volume. When playing " transverse " records, the potentiometer-controls 80 and 66 are set - to the extreme up and down positions respectively, i.e. resistances 63 and 61 short-circuited, while potentiometer-controls 65 and 79 are used for controlling volume.