An apparatus for a coaxial transmission line is provided. The apparatus can include a first and a second section of a conductor of the coaxial transmission line and a connector for connecting the first and the second sections in end-to-end relation. Each of the first and the second sections of the conductor have an exterior lateral surface and an interior lateral surface. For inner conductors, the connector is connected to the interior lateral surfaces of the first and second sections of the conductor. For outer conductors, the connector is connected to the exterior lateral surfaces of the first and second sections of the conductor. The connector allows the inner and outer diameters of the annulus between the inner and outer conductors line to be substantially uniform along the length of the coaxial transmission line.