An example disclosed example includes a housing; a printed circuit board carried by the housing and including an antenna feed aperture; a logic circuit disposed on a first side of the printed circuit board, the logic circuit to generate blink data comprising pulses and data; an antenna disposed on a second side of the printed circuit board, the antenna in electrical communication with the logic circuit via the antenna feed aperture, the antenna configured to transmit the blink data; a dielectric potting material to protect the logic circuit; and a seal to cover the antenna feed aperture, the seal to prevent the dielectric potting material from entering the antenna feed aperture.