Broadcast Fields
at Tucson Mountain

RF fields at an American Tower Corporation antenna site located on Tucson Mountain, near Tucson, Arizona, were evaluated on the ground and on the six towers that are located in close proximity to each other. A ground level field survey was used to categorize areas of the site according to composite RF field levels produced by six high power FM radio stations and seven high power TV stations.

Theoretical analysis of near-field levels on each tower were also performed and compared with far-field methods to arrive at practical RF exposure mitigation procedures to apply during tower work. It was shown in the study, for example, how the gain of commonly used VHF broadcast antenna arrays can exhibit substantial gain reduction in the near field, suggesting that the application of far-field calculation methods can sometimes substantially over-project the magnitude of the actual RF field level near an antenna.