Power Feed Equipment for the North Atlantic Link

The principal objectives in the power plant design for the Transatlantic cable system were as follows: 1. To stress reliability in order to guarantee continuous dc power to the electron tubes that form an integral part of the submerged repeaters. This is essential, not only to be able to maintain continuous service, but to prevent cooling and contraction of the repeater components, especially the tubes. 2. To provide close dc cable current control to ensure constant cathode temperature and regulated plate and screen potentials for the repeater tubes. These operating conditions are essential both for obtaining maximum life from these tubes and for maintaining constant transmission level. 3. To control and limit the applied dc cable potentials in order to minimize the dielectric stresses. The life of certain capacitors in the repeaters is critically dependent upon these stresses. Moreover, momen* Bell Telephone Laboratories. 139 140 T H E B E L L SYSTEM TECHNICAL JOURNAL, JANUARY 1 9 5 7