GB571462A - Improvements in or relating to tail wheel mountings of aircraft - Google Patents

Abstract

571,462. Wireless receiving circuits. LIPS, J. Nov. 26, 1943, No. 19764. Convention date, Nov. 10, 1942. [Class 40 (v)] A short-wave adaptor includes a mixeroscillator which, during reception of long and medium waves, is used as an aperiodic amplifier. In the Figure the short-wave adaptor is shown in the position for receiving short-wave signals. With switch S2 in the left-hand position, aerial A is connected to a short-wave coil L1 coupled to ooil L2 which, with one of the condensers C1, C3, C5, forms an input circuit tuned to the mid-frequency of one of the short-wave bands, selection being made by switch S1. The input circuit is coupled through a small condenser Cs to the grid of the hexode portion of a triodehexode frequency changer MR. The triode portion is arranged as an oscillator having a tuned circuit formed from an inductance L4 and one of the condensers C2, C4, C6 selected by switch S3. Switch S3 is operated in cooperation with wave-band switch S1 so that, for each short-wave band, there is provided at the anode A1 an intermediate frequency-which lies within the reception range of the receiver (not shown) with which the adaptor is designed to co-operate. This intermediate frequency is fed through condenser C9 and lead AK to the input terminal of the receiver, and tuning to the individual stations in each short-wave band is effected by the normal tuning means of the receiver, and gives a partial band-spreading effect. For receiving long or medium waves, switch S2 is moved to the right-hand position to connect the aerial A to the grid of the hexode portion of MR which now acts -as a highfrequency amplifier. Condenser Cs is too small to byepass the long and medium frequencies. The oscillator portion is inoperative during the reception of long and medium waves.