mos, was assigned the mission of operating the Los Alamos terminal of the Eniwetok— Los Alamos Ratt circuit and providing communication support to TG 132.1 Headquarters, Los Alamos. 3.17.3 Preliminary Planning Initial operational planning was hampered by the absence of a TG 132.1 Communications Officer, who reported for duty on 2 June 1952. Lieutenant Colonel King, J-5 Section, Headquarters, JTF 132, assisted in preparation of the Communications Status Report, 8 May 1952. Requirements were received through monthly status reports, communications letters, and by personal contact. In many instances prospective users had to be contacted to amplify or clarify requirements, since many were unfamiliar with facilities available and communications in general. Each requirement was usually handled separately and submitted to the appropriate agency for implementation as soon as the necessary information became available. This resulted in earlier implementation and a more even workload on the personnel concerned. Communications requirements were consolidated into status reports aated 8 May, 16 July, and 18 August. The last report was in the form of a tentative TG 132.1 Communications Plan. This report was revised and issued as Annex G to TG 132.1 Operations Plan 1-52. Operation Ivy communications requirements were submitted to either CJTF 132 or AEC, SFOO,for implementation and to CJTF 132 for approval. In all instances CUTF 132 furnished the required support through directives and requests to subordinate Task Groups and other agencies. Liaison prior to establishmentof the overseas Headquarters was maintained by several visits of J-5 Section, Headquarters, JTF 132, personnel to Los Alamos and by one visit of the TG 132.1 Communications Officer to Headquarters, JTF 132. The planning stage was essentially complete on 21 August 1952, at which time the TG 132.1 Communications Officer proceeded to Eniwetok. 3.17.4 ‘ On-site Operations and Rehearsalg Prior to arrival of TG 132.1 Headquarters at Parry Island, about 15 September, a TG 132.1 telephone directory was published; office and laboratory telephone and intercom systems were installed; the boat-pool, airstrip, and other immediately required radios were installed; and a schedule of installation, based on probable usage dates, was furnished H&N. The installation and issue of equipment required to furnish facilities shown in the TG 132.1 Communications Plan proceeded on schedule and met the users’ requirements. The H&N property clerk signed for all communications equipment drawn from TG 132.2 stock and re- issued it to the appropriate H&N shop supervisor, who in turn issued it on subcustody to users. During the overseas operational period, weekly communications conferences with JTF 132 communicationsofficers were held from about 20 September until 10 October, after which several communications rehearsals prior to Mike Shot were conducted. The success of TG 132.1 communications was totally dependent on support and liaison with other agencies. The Section J-5 JTF 132 staff rendered every assistance practicable to this Headquarters in the performance of its communications mission. 3.17.5 3.17.5.1 Control Station Communications Mike Shot , The Control Station for Mike Shot was located in the Firing Room and the Gunnery and Landing Force Office, USS Estes. Edgerton, Germeshausen & Grier, Inc., (EG&G) provided two television receivers, operating in the frequency band 1990 to 2110 Mc, and several presentations which showed the timing-signal and Go-No-Go indicators and the monitor dials for important systems of the device. A control panel was located between the two presentation channels in the Firing Room. This panel controlled, by the use of three 250-watt Motorola 47