CHAPTER Ii, SECTION 6 Departmentincluded telephone and teletype sec- tions at each atoll, plus a directory section and a television section at Elmer. While the communications responsibilities increased several fold during HARDTACK,it was necessary to increase communications personnel requirements only 22% over REDWING. TROPOSPHERIC SCATTER SYSTEM. Early in 1957 the planned scope of Operation HARDTACK indicated the need for a new Communications System between Bikini and Eniwetok Atolls. It was essential that the system carry with utmost reliability a large number of radio telephone, teletype, and data channels plus a wide frequency band voice cryptographic system in the process of development by the National Security Agency. As a result of the efforts of the AEC Com- munications Engineer and the JTF-7 Communications Section, a 72-channel Tropospheric Scatter System, excess to military requirements, was located. The Air Force experimental system, engineered by Lincoln Laboratories, Massachusetts Institute of Technology, was in operation between North Truro, Massachusetts, and Stewart AFB, Newburgh, New York. A survey was conducted ii n May 1957 by the Contractor’s engineers, and it was determined that the system would meet the requirements at EPG. The sys- tem was dismantled and crated under the Contractor’s direction and wasairlifted to EPG in six C-124 aircraft. The equipment was placed in dehumidified storage to await the completion of the addition to Building 488 at Elmer and the new Communications Building, No. 204, at Nan. Installation of the system paralleled building construction at both sites. The Tropospheric Scatter System was placed in full operation on 8 March 1958. Two-way service between Elmer and Nan included 10 dial trunks and 6 ring-down trunks for general telephone service, 10 hot-line intercom channels, three teletype channels, one IBM data circuit, and two voice cyphony channels. The dial trunk installation made it possible to dial the Nan operator from any Eniwetok Atoll _ telephone and allowed the Nan operator to dial any number in the Eniwetok Atoll. Voice quality on both the general service channels and the cyphony channels was comparable to commercial land-line telephone standards. 4. e fo 4 A. ak | ' | . ! amgt Sy. woe. “ - 8 Sony ' web . all, aw — . :4 “is Gea £ $ awe ee « wt Sake og ag RT te . SOEST Ee ee er > + apt Mme a (Neg. No. W-V-341-3) Figure No. 2-152. Building 488 and Tropospheric Scatter Antennas — Elmer. Page 307