NOVELTY - The gearbox has service cables (110a, 110b) extended by the planetary gearbox, where each service cable enters the planetary gearbox by a fixed planet stage (106c) of the planetary gearbox and extends through a central shaft (130) to a stationary portion (120a) of a slip ring assembly for providing connection to a rotor of a turbine. The slip ring assembly is arranged proximal to input of the planetary gearbox. A cable guide defines a fixed path for the cable between a cable entrance and the central shaft. A portion of the cable extends along radial direction by the gearbox.    USE - Planetary gearbox such as multi-planet planetary gearbox and fully-coaxial planetary gearbox, for a renewable energy turbine (all claimed) such as wind and tidal or hydro-electric turbines, for power generation from renewable sources.    ADVANTAGE - The gearbox negates need to provide a hollow shaft, which extends fully through the center of the gearbox, and enables a solid shaft, which is coaxial with the input shaft without impacting on service cabling in sizing and design of the final stage of the gearbox often a highly stressed and durable stage of the gearbox, thus avoiding limitation on dimensions of the solid shaft. The slip ring assembly is arranged with a hub of the rotor so as to simply access the slip ring assembly during installation and maintenance process. The gearbox can pass services through the rotating flexible coupling so as to provide drive connection and additionally torque overload protection between the gearbox and a driven device and provide improved flexibility in providing services to the rotor. The cable enters the gearbox through a grounded part of the gearbox, and is routed to the central shaft by utilizing the fixed planet stage of the gearbox, thus providing a gearbox designer with improved degree of freedom in arranging the cable routing and/or the gearbox stages.    DETAILED DESCRIPTION - The service cable is a data and power cable. The planetary gearbox is a multi-planet planetary gearbox and a fully-coaxial gearbox. The fixed planet stage is a final stage of the gearbox. An INDEPENDENT CLAIM is also included for a renewable energy turbine.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic cross-sectional view of a fully-coaxial planetary gearbox showing a service cable.    Output shaft (104)    Fixed planet stage (106c)    Service cables (110a, 110b)    Stationary portion (120a)    Central shaft (130)