A single interconnection unit provides all of the signal connections required to operate a group of PMTs and to transmit signals therefrom to acquisition electronics exterior to an enclosure for the PMTs in a nuclear scanner. In a preferred embodiment, the interconnection unit provides a shielded differential pair connection for RF signals; power supply connections for the PMTs, providing all of the voltages required to operate PMTs and the associated circuits, as well as connections for those signals and appropriate ground planes. Preferably, interconnection unit comprises a flex circuit with end connectors designed to connect to a power supply unit and an acquisition unit remote from the PMTs. Connection points are provided along the length of the flexible circuit for connection to a PMT and provide all of the necessary connections for that PMT, including shared power supplies and ground buses, as well as connections dedicated to a particular PMT, including a dedicated RF differential pair, a dedicated digital line, and an associated ground plane.