GB530220A - Improvements in aerial systems for radio-receivers - Google Patents

Abstract

530,220. Wireless receiving systems. PHILIPS LAMPS, Ltd., and KAYE, J. B. June 30, 1939, No. 19134. [Class 40 (v)] A transmission line for coupling an aerial to a receiver comprises two or more pairs of lines with transformers or other impedance matching devices at the ends of the lines arranged so that the wires provide at least three transmission circuits of which two or more form physical circuits and at least one a phantom circuit. The down lead of an aerial 10 is connected to the primaries 11, 12, 13 of a triple transformer system the secondaries 16, 17 associated with the primaries 11, 13 being connected to a pair of wires 18, 19 while the secondary 20 is connected to tappings of the coils 16, 17. The wires 18, 19 thus provide physical circuits for the coupled systems 11, 16 and 13, 17 and a phantom circuit for the system 12, 20, and are connected to a similar transformer system in the receiver input circuit. In Fig. 2 a similar arrangement is shown for coupling up an aerial 22 which acts as a dipole for short waves and a horizontal aerial for medium and long waves. The two limbs of the aerial are connected by a short wave coil 23 which is joined by a line 24 to the primaries 25, 26 of the long and medium wave transformers. In a further modification, Fig. 3 (not shown), in which both a dipole and an ordinary broadcast aerial are employed, the tappings for the phantom circuit are connected directly to the arms of the dipole.