a workpiece support pedestal includes an insulating puck having a workpiece support surface , a conductive plate underlying the puck , the puck containing electrical utilities and thermal media channels , and an axially translatable coaxial rf path assembly underlying the conductive plate . the coaxial rf path assembly includes a center conductor , a grounded outer conductor and a tubular insulator separating the center and outer conductors , whereby the puck , plate and coaxial rf path assembly comprise a movable assembly whose axial movement is controlled by a lift servo . plural conduits extend axially through the center conductor and are coupled to the thermal media utilities . plural electrical conductors extend axially through the tubular insulator and are connected to the electrical utilities .