A relative phase shift is induced in the signals of a pair of identical
orthogonal antennas such that when the signals are combined the signals
are 90 degrees out of phase. This is done in order to eliminate the null
along the axis between the two dipole moments of the antennas such that
the system has equally good reception from all azimuth angles over a
broad range of frequencies. The phase shift is accomplished with the use
of single pole operational amplifier circuits whose pole frequencies are
adjusted by means of a potentiometer prior to implementation of the
antenna system.