Systems for establishing electrical interconnections for helmet-mounted devices are disclosed. During operation, the system assigns to a non-routing node coupled to a switch a virtual routing node identifier unique to the non-routing node. The front portion of the frame has a top section and a bottom section. The rotor face defines a first rotor port and a spaced second rotor port, and a rotor body thereof defines a first subterranean passage extending fully beneath the plane of the rotor face. The area of the flow passage is changed by movement of the fixed seat orifice axially with respect to a contoured plug assembly. The apparatus may include very high frequency antenna and a frequency selective surface structure adjacent to the VHF antenna.