GB512772A - Improvements in or relating to wireless receiving apparatus - Google Patents

Abstract

512,772. Adjusting wireless apparatus. TELEFUNKEN GES. FUR DRAHTLOSE TELEGRAPHIE. Dec. 6, 1937, No. 33653, Void. Convention date, Dec. 5, 1936. [Class 37] [Also in Group XL] The tuning scale, arranged in front of the sound opening of the loud speaker, comprises a strip or a plurality of spaced strips bearing stations names or other indicia. Figs. 1, 2, show transparent strips 3, for example, of glass, bearing scale indications and, or station markings, and co-operating with a tuning pointer 4 mounted on a guide bar 6' and moved parallel to the direction of the strips 3 in known manner by the tuning control 5, the strips 3 being spaced to permit the egress of sound from the sound opening 2. A sound permeable textile sheet 8 covers the sound opening and is disposed behind the strips 3 which are illuminated by lamps 12. Alternatively, the lamps 12 may be located so that the strips are illuminated partly or wholly by reflection from the loud speaker diaphram 11. A further light reflecting sound permeable textile sheet may be provided across the front of a baffle 10 to enhance the lighting effects. In a modification, the strips 3, Fig. 3 (not shown) are opaque, for example, of sheet metal or mouldable material and carry indicating projections and separately formed letters for the station names which therefore appear as shadows against the illuminated textile screen 8. Alternatively, the station markings may be stamped out of the strips 3 so that the letters appear bright against the dark background of the strips. The scale bearing strip or strips 3 may alternatively, be mounted vertically and traversed by a horizontal pointer. The strips 3 may be supported by cross strips, the dial structure then forming a grille with relatively large openings so that substantially no resistace is offered to the passage of sound. The strip or strips 3 may also be formed to guide the sound. Thus, Fig. 6 shows the dial structure in the form of a single strip 3 having a conical sound directing guide on the rear thereof which houses lamps for illuminating the dial, and the tuning indicator comprising, for example, an optical system for projecting a light beam for forming a shadow on the dial.