GB159003A - Improvements in aerial systems for wireless signalling - Google Patents

Abstract

159,003. Franklin, C. S., Picken, W. J., and Robb, J. G. Nov. 17, 1919. Directive signalling; duplex signalling. - ln aerial systems such as those described in Specifications 24098/14 and 5783/15, in which a pair of directive aerial systems A, B spaced in the direction of signals is combined with a common receiver C, a plain non-directive aerial is combined with each of the systems A, B so as to give pronounced unidirectional results. In a modification, the radio gonimeter coils are connected in series to the tuning-condenser E, equal condensers H in series with each other being shunted across the condenser E and the point between each pair of condensers H being earthed through the inductance and capacity I, J. A search coil F is coupled to the radio-goniometer coils D<1> - - D<4> and is connected to a tuned circuit as shown. The receiver is preferably midway between the aerial systems. By variously mis-tuning the circuits A, B, K different polar diagrams can be obtained. In one case, reception may be made zero in three controllable directions, and, in another, extreme insensitiveness is obtained within an arc extending 60‹ on either side of the direction opposed to that of the maximum sensitiveness. The invention is stated to be particularly applicable to duplex working and to preventing interference.