Abstract: A wheeled transporter is placed at the periphery of the tube bundle which extends up from its tube sheet within a nuclear steam generator shell. The transporter is formed in hinged sections which can be disengaged as required at the periphery of the tube bundle. A cable attached to each end of the transporter extend through the handholes for movement of the transporter along the bundle periphery. Pistons on the transporter are controlled remotely to extend into engagement with the internal wall of the generator shell to selectively immobilize the transporter at any desired peripheral position and thereby form a steady base for maintenance and inspection devices mounted on the transporter.

Abstract: A line unit interfaces voice band signals and wide band signals extending from D.C. into the voice band between an analog line and a digital telecommunication facility. The line unit includes an analog to digital converter, a control circuit for generating one of two control signals and a line circuit. The line circuit includes a hybrid circuit in a first signal path for carrying voice band analog signals, and a second signal path for carrying wide band analog signals from the analog line. The signals in either signal path are transmitted to the analog to digital converter for encoding by way of a first switch or a second switch connected in series with the first and second signal paths respectively. The first and second switches are alternately conductive in response to one or the other of the control signals respectively.