HE receiving antenna directivity patterns and gain for ionospheric propagation model predictions for shortwave broadcasting

Elevation-plane relative directivity patterns of a 9-ft rod measured with the XELEDOP full-scale HF antenna pattern measurement system are compared with values assumed by the Voice of America (VOA) and the British Broadcasting Corporation (BBC). Values of such directivity patterns and gain for a 7.5-ft monopole with sixteen buried ground radials, measured at the same site, are compared with predictions of directivity and gain made with the numerical electromagnetics code (NEC). An extensive set of recommendations is offered, regarding the appropriate assumptions for the receiving antenna in ionospheric propagation prediction programs