GB702298A - Tuning control mechanism for broadcast receivers - Google Patents

Abstract

702,298. Adjusting radio apparatus. LOEWE OPTA AKT.-GES. Oct. 26, 1951 [Oct. 26, 1950], No. 25155/51. Class 40 (5) The tuning indicating device of a radio receiver comprises, in addition to the normal scale and pointer, means for producing a beam of light which moves simultaneously with the pointer and impinges on adjustable slides located adjacent to the scale. The beam of light produced by the rectangular aperture in the tube c impinges on a translucent slide h which is adjusted in position so that when the correct tuning point is reached the beam overlaps the opaque portion k of the screen by an equal amount on both sides. The light may be passed through a coloured filter or the slides may be coloured. In one alterriative arrangement the apex of a V-shaped beam coincides when the correct tuning point is reached with a V-shaped translucent gap in the opaque portion of the slide while in another arrangement a red beam of double wedge shape coincides at the correct tuning point with a translucent double wedge on an otherwise red screen to produce an uninterrupted red surface. In Fig. 4 the beam of light is produced by reflection from a mirror i and the lamp is also used to light a pointer comprising a glass rod b with a white translucent coating. The slides h are supported on the edge of the scale.