GB746985A - Improvements relating to antenna circuit arrangements for radio receivers - Google Patents

Abstract

746,985. Aerials. BLAUPUNKT-WERKE GES. March 18, 1954 [March 20, 1953], No. 7980/54. Class 40 (7). An antenna arrangement comprises at least one ferromagnetic rod on which are placed spaced windings connected in series; the associated tuning capacitor also being divided into two parts connected one to each end of the windings. The windings are preferably of equal size and arranged substantially symmetrically at or near the ends of the rod 1 as shown at 2 and 2<SP>1</SP>. They may be lattice wound, wave wound or honeycomb coils, the high potential layers being as far as possible from the rod and connected to the two parts of the tuning capacitor 3 and 4 the other plates of which are earthed. Capacitor parts 3 and 4 are ganged together for tuning and may also be ganged with the oscillator tuning capacitor in a superheterodyne receiver. When it is desired to operate the arrangement over two wave ranges a further coil 6 in series with the others may be provided centrally as shown. This is carried by an insulating distance piece 8 and can be trimmed by a threaded tuning slug 9. When not required coil 6 can be shorted out by switch 7 ; this can be done without detriment to reception on the higher frequency range because of the large diameter on the coil. The single ferrite rod 1 may be replaced by a plurality of thin ferrite rods more or less tightly packed.