A myelinated nerve fiber is modeled as a straight thin wire antenna and stimulated by a current generator at the fiber beginning. The model is based on the corresponding homogenous Pocklington integro-differential equation for the perfectly conducting wire in a lossy unbounded homogenous space, where the activated node of Ranvier is modeled as a thin wire junction with an additional current source. The additional current source represents the ionic current of the activated Ranvier’s node. The intracellular current results are obtained for the nerve fibers of two different diameters, stimulated by different rectangular pulses. The thresholds are determined by related strength-duration curves.