In a previous paper [1], we studied transient radiation from scalar collimated volume source distributions subjected to impulsive excitation. In this paper, we extend our analysis and results to the case of nonimpulsive excitation, paying special attention to the parameterization of the radiation pattern of three-dimensional (3-D) ellipsoid source distributions driven by square pulses of finite duration. We study the role both of the source's space distribution and of the square pulse duration on the generation of well-collimated short-pulse fields. In particular, we explore the source's angular and range resolutions as functions of the transverse and longitudinal dimensions of the source (for a fixed source volume) and of the pulse duration.