OTA measurement techniques have, and will continue to have, a key role in evaluating the performance of modern antennas and wireless devices. The new random line-of-sight (random-LOS) measurement setup, offers the evaluation of the OTA performance of different types of devices, for example car antennas and small wireless devices in the random-LOS environment. A plane wave is synthesized in the test zone of the OTA setup, where the far-field of a radio base station can be emulated. We present measurements and simulations of the random-LOS OTA measurement setup employing a reflector antenna, with a dual polarized linear array feed, operating at the 28 GHz band. An analysis of the power and phase field distributions in a cylinder and a circular test zone are presented. The computed standard deviation of the power distribution is approximately 1 dB within a circular test zone, with a diameter of 0.3 m. The standard deviation of the phase, within the same test zone, is less than 15 °. The radiation patterns of a horn antenna have been measured in the random-LOS measurement setup and shown a good agreement with the theoretical values.