One-dimensional (1D) photonic crystals have been constructed by connecting segments of coaxial cable of differing characteristic impedance. Impurities have been introduced into these crystals by inserting cable segments to break the crystal symmetry. This system provides a simple way to study 1D photonic band structure effects with complete control over impurities in the lattice. We have studied the effects of the size, number, and location of defects in the lattice. We have also measured directly the concentration of energy in the steady-state electromagnetic fields within doped crystals, and observed the influence of the defects on the phase (dispersion). A modified dielectric stack model was developed to describe this system, with the results in excellent agreement with our measurements. Our findings compare favorably to previously published measurements of transmission and phase change in three-dimensional photonic crystals.