WLW's 500,000-watt authorization included the requirement that the station limit its nighttime skywave signal toward Canada to the equivalent of 50,000 watts, which led to the construction of two shorter towers, electrically a quarter wavelength in height and separated by a half wavelength, that were located 1850 feet (560 m) southwest of the main tower. The two shorter towers were fed using trolley car wire to produce an 85 kW signal at 96 degrees out-of-phase with the principal signal, which produced a null in the opposite direction from the main tower.