A conducting housing for use in a coaxial cable distribution system is of larger length than width and defines an RF signal path therein. A part of the RF signal path is the inner conductor of inner and outer approximately coextensive conductors. The inner conductor except near its ends has only air separating it from the outer conductor. The outer conductor will usually be of a U-shape lying, in section, on three sides of the central conductor. The outer conductor may be structally combined with an insulating plate supporting the remainder of the RF circuit.