The directions of selected nulls in the characteristic pattern of an array of signal converting elements are controlled independently of the direction of the main beam of this pattern and substantially independently of the strength of the main beam. This is done by constructing each signal converting element either of two mutually perpendicular dipole transducers and an omnidirectional transducer, or their equivalent. Array nulls are then rotated independently of the main beam by varying the relative weights given to the signals associated with the transducers comprising each element.