A cable spacer for maintaining positions of a plurality of cables relative to each other is provided. The cable spacer includes a frame, a hanger and a plurality of clamps that couple the plurality of cables to the frame to maintain the positions of the plurality of cables relative to each other. A first clamp includes a receiver with a first arcuate surface, and a keeper that is adjustably coupled to the receiver to be adjusted from a first position to a second position to interfere with removal of the region of the first cable from the first concave pocket. A locking system adjusts the keeper from the first position to the second position relative to the receiver, and maintains the keeper in the second position to exert a compressive force on the first cable, urging the first cable into the first concave pocket.