A method for fabricating radar array apertures comprises the steps of: inserting a plurality of clips into a ground plane, mounting at least one first strip on a first subset of the clips and mounting at least one second strip on a second subset of the clips and on the at least one first strip so as to form an assembly. Locks are formed on outer surfaces of each auxiliary housing, and engaging portions for holding the auxiliary housing in the frame by being engaged with the lock portions are formed on inner surfaces of each housing accommodating recess. When the cover is used alone it engages a frame or a wall circumscribing the access opening. The relative positions of the first and second bonding pads are varied so that the first wire can reach light-emitting elements in different positions in different blocks without crossing the second wire in any block. An aggregation point interfaces a medium voltage power line with a point-of-presence, and a power line bridge enables flow of communications signals between the medium voltage power line and a low voltage power line across a distribution transformer.