Abstract: A low loss coaxial cable has a central supporting rod of plastic, covered in metal and forming the inner conductor or core of the coaxial cable. An intermediate insulation made of a dielectric material surrounds the inner conductor and an outer metal conductor surrounds the intermediate insulation. The central rod is made of polytetrafluoroethylene (PTFE) having a relative density greater than or equal to 1.6. The intermediate insulation has a relative density less than 1.2 and the ratio of the density of the dielectric constituting the intermediate insulation divided by the density of the PTFE constituting the rod lies in the range of 0.15 to 0.75.