Demco Star Make Demco Model Star Mic Wiring 1 - Ground 2 - Audio 3 - PTT Demco Star Technical Specifications AttributeDetails ManufacturerDEMCO ModelSTAR Product CategoryTransceiver Mic Wiring Pin 1 – Shield / Ground Pin 1 – Switch Line Pin 2 – TX / PTT Pin 3 – RX Pin 4 – Mic Audio