Abstract: An improved transmission line for RF communications. A transmission line comprising a center conductor; a dielectric layer surrounding the center conductor; a bimetallic outer conductor including an outer conductive layer and an inner conductive layer; wherein the outer conductive layer and the inner conductive layer are of differing materials; and the inner conductive layer is copper or copper alloy; and an insulating jacket surrounding the bimetallic outer conductor. Other aspects do not require the center conductor or the dielectric layer. Further aspects include a bimetallic center conductor. Advantages of the transmission line include imperviousness to signal loss due to surface abnormalities (due to inner conductive layer being interior to and encapsulated by outer conductive layer); the potential for significant cost savings in material; excellent RF communications signal propagation; and a significant reduction in weight.