GB566135A - Improvements in or relating to radio-receivers adapted to be automatically tuned to a number of pre-determined stations - Google Patents

Abstract

566,135. Push-button wireless sets. PHILIPS LAMPS, Ltd. (Naamlooze Vennootschap Philips' Gloeilampenfabrieken). May 6, 1940, No. 8125. [A Specification was laid open to inspection under Sect. 91 of the Acts, Nov. 11, 1940.] [Class 40 (i)] [Also in Groups XXXVI and XL] In the selection of short-wave stations, band-spreading arrangements are automatically brought into use. As shown in Fig. 1, the depression of a short-wave button operates contact 68 to mark the short-wave position to a disc 52 coupled to the wave range switch, one of four contacts, 69 ... 72, to mark the appropriate part of the short-wave band to a disc 54 coupled to a switch for connecting auxiliary condensers 46 ... 48 to the oscillator circuit and two contacts such as 77, 78 individual to the station and co-operating with profiled discs 59, 62 to cause condenser 16 to tune the preliminary circuit to the middle of the selected portion of the short-wave band and bandspreading condenser 45 to tune the oscillator appropriately for the selection of the station. A relay 82 in series with clutch magnets 84 and 83 prevents the setting of the tuning condenser until the range switches have been set and a relay 90 delays the setting of the band-spread condenser until condenser 15 has been set. In a modification, Fig. 2 (not shown), the preliminary circuit is tuned by fixed condensers connected up at the same time as the fixed condensers in the oscillator circuit and the ordinary oscillator-tuning condenser is used as the band-spreading condenser. In a further arrangement, Fig. 3, in which the buttons act mechanically, the operation of a short-wave button causes the latching plate 200 to release a disc 152 coupled to the wave-range switch which is then moved to the short-wave position, operates switches 98, 41 and 42 in accordance with the position of an adjustable member such as 209 to select the appropriate part of the short-wave range in the preliminary and oscillator circuits and finally sets the bandspread tuning condenser 45 by means of an adjustable member 208. The normal tuning condensers are only operated by the long and medium-range buttons such as 213.