Factors affecting the propagation and reception of broadcasting signals in the u.h.f. bands

The limitations imposed by the propagation path on the transmission of u.h.f. signals are considered. The magnitude of diffraction losses imposed by terrain and by buildings and trees is discussed, and the advantage to be derived from the use of high aerials is emphasised. Losses resulting from the siting of receiving aerials in house lofts and living rooms are also considered, as well as the limitations imposed by the existence of standing-wave-field patterns and long-delay reflections or echoes. The quantitative effect of each limitation is demonstrated by the results of measurements.