The other NEC (BSC) an asymptotic complement

In choosing a title for this paper, it was difficult to decide how to fit a high frequency asymptotic method based computer code into discussions primarily focused on a method of moments code. In considering the possibilities, the title chosen seems appropriate. Based on Webster\´s dictionary, "complement" means "that which completes or brings to perfection". That lofty ideal certainly has been the goal from the onset. The latter may not have been entirely achieved yet, but still much progress has been made in 30 years. The paper gives an overview of the development of an electromagnetic computational engineering design tool from the high frequency electrically large structure point of view. The NEC-basic scattering code (NEC-BSC) can act in its own right to predict the antenna pattern distortion due to the presence of large complex structures or the spatial coupling between antennas in such an environment. In addition, it can synergize with a full wave code, like NEC-MoM or MiniNEC, to provide even more versatility. Some recent results illustrate the concepts.