L multiplex terminals provide the several stages of modulation required to translate telephone channels into the broad basebands which can be transmitted. on long‐haul systems. The group and supergroup equipment has been redesigned incorporating many new features. Pilot‐controlled regulators are provided to improve performance. Plug‐in modules and automated monitoring facilitate maintenance. The equipment is arranged to reduce office cabling and installation cost. By the use of transistors and other newly developed devices and components, a size reduction of 10 to 1 has been achieved and the required power greatly reduced.