ground shells 5 of the coaxial connectors protrude from the lower face of the linear groupers in the grouper frame one or more notches 21 may be present in the outer surfaces of grouper frame 20 to form a part of a hold down latching mechanism to hold the system to a pcb 70 fig7 describes a header chute 40 formed from an elongated plastic block which has slotted bores 43 molded into it in parallel linear array to hold the ends of the coaxial connectors the ground shells 5 of which when inserted into bores 43 connect with signal contact pins 42 set in the bores each header chute has alignment apertures 41 molded into each end signal contact pins 42 are set into the bottom face of each bore 43 and extend into the bore for termination of the signal contacts 3 and extend below the bottom of the header chutes to make contact with connector receptacles of a pcb 70 between each bore 43 on an outside edge near the bottom of the header chute is molded a bead 45 which protrudes from the planar surface each bead 45 fits into a ground plane alignment aperture 51 to hold ground plane 50 tightly to the slotted face of header chute 40 along the length of header chute 40 are resilient leaves 52 slit from ground.