A numerical technique is presented that is capable of calculating the transient response of a thin-wire antenna or scatterer loaded by a network. The electromagnetic formulation is an adaptation of a well-validated and widely used code. This code is based on an electric field integral equation and employs point matching and nine-point Lagrangian interpolation functions. The network is treated by a nodal analysis and can contain a finite number of lumped and possibly nonlinear elements. The formulation is cast in the time domain, and the solution is obtained by a time-stepping procedure. The numerical approach is outlined, and the responses of several examples are presented.