World's Most Powerful Radio Transmitter, Built for Navy by RCA, is Dedicated 

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from Radio Age, January 1954

A radio message flashing from a giant antenna strung across a deep valley in the Cascade Mountains of Washington State circled the world on November 17, 1953, to bring all of the far-flung elements of the United States Navy within direct and instant reach of their homeland. The historic message signaled the entry into the nation's service of the most powerful radio transmitter ever built a 1,200,000-watt station erected by the Radio Corporation of America for the U. S. Navy in the remote Jim Creek Valley some 55 miles northeast of Seattle. Tapped out in wireless code by Brig. General David Sarnoff, Chairman of the Board of RCA, the dedication message as dictated by Admiral Robert B. Carney, Chief of Naval Operations, gave dramatic proof of the station's power as it penetrated to vessels in distant seas and to shore stations on the five continents. 

Brig. General David Sarnoff taps out first message from Jim Creek to naval units around the world as Admiral Robert B. Carney looks on.

  '"With this first message we forge another link between you and your homeland," Admiral Carney told the scattered units. "With it, we build a new security channel from America to the naval units which form its outer ramparts of defense." Six minutes later the acknowledgments began to re turn, some of them relayed four or five stages to reach Jim Creek Valley. The first came from the battleship Wisconsin, operating off Japan. Then came word from the carrier Yorktown, the destroyer Floyd B. Parks and the submarine Bluegill in the western Pacific; the sub marine Sablefish in the North Atlantic and the cruiser Pittsburgh in the South Atlantic; the carrier Tarawa in the Mediterranean and the destroyer Charles S. Sperry in Florida waters. As the replies arrived, Admiral Carney and General Sarnoff plotted the location of the units on a world map set up for the ceremony at the transmitter site. Along with the acknowledgments from the naval units, RCA Communications relayed word of receipt of the message at distant locations in its 65-nation radio circuit and aboard passenger liners at sea. 

Project Took Six Years To Complete 

The ceremony marked formal acceptance of the powerful transmitter by the Navy from RCA, whose engineers and communications experts had worked for six years with Navy engineers to complete the $14,000,000 project. The result of their labor, put to its first test with the initial message, is a transmitter at least twenty-two times more powerful than the strongest commercial station in the country, emanating a very low frequency (VLF) signal capable of penetrating the magnetic disturbances that interrupt higher frequency communications and able even to reach through water to make contact with submarines cruising below the surface. Turning the installation over to Admiral Carney, General Sarnoff said: "No branch of the armed services has been more closely associated with RCA than the Navy; none has teamed with us more intimately in devising and producing electronic implements of defense. None, certainly, has based its existence more completely on the science of communications, which we pursue. A scroll of our joint ventures would unfold a triumphant story of the electron harnessed to the service of the nation. For more than forty years, we have labored together to produce the radio, sound and electronic equipment that gives the Navy cohesion and mobility. We have demonstrated to a unique degree how team- work between private industry and the military forces contributes to the nation's welfare." Reviewing past highlights of RCA-Navy partnership in developing and producing electronic equipment, General Sarnoff mentioned the first modern shipboard radio receivers for the Navy, direction finders, radio transmitters, diversity reception for ship to shore use, homing devices for planes returning to the mother ship, ship- board radar, radio altimeters for Navy patrol and torpedo bombers, one phase of loran, the analogue computer that simulates test runs of guided missiles, and the new combat information center materials with which naval units are being equipped. 

Recalls Navy Helped Found RCA 

He recalled that the Navy, "more than any other organization in or out of government, gave us being" by insisting upon the establishment after World War I of an American radio communications company an insistence that resulted in the formation in 1919 of RCA with the mission of setting up a world-wide wireless communication network. "Of course, our company has branched into other fields, finding new applications in radio, television and associated electronic arts," General Sarnoff said. "But it has as this monument of stone and steel and copper testifies remained faithful to that original radio wire- less trust." He added that the giant transmitter is "an enduring testimonial to teamwork" symbolized by the 175 business firms that supplied RCA with parts and components for the project. "They deserve high commendation for their part in a job well done a job that typifies American industry's teamwork with the armed forces," he said. Presenting Admiral Carney with the keys to the control panels of the transmitter. General Sarnoff said: "I turn over to you, on behalf of the Radio Corporation of America, the most powerful radio transmitter ever built. May I express the wish, which I know all in our armed forces share, that this powerful instrument for transmitting intelligence, may add to our national security and to the peace of the world." Admiral Carney, accepting the installation for the Navy, spoke of the close liaison between the armed services and private industry in meeting the complex requirements of national security. "This great installation at Jim Creek is the newest of RCA's answers to our requirements and is a most eloquent testimonial to the fact that America's great strength lies in the wedded efforts of all elements of our population," he said. "It is a strength built up of the closely knit sum of industrial, economic and military potentials which are welded together by a common objective and a common determination to achieve great national team work." He emphasized the importance of the great transmitter in an era when nuclear power for ships promised to become a reality. Such ships would be able to remain at sea for long periods, indicating "an increasing need for the use of effective radio in directing our tremendous and complicated maritime operations," he said. Refer ring to the ability of the transmitter to communicate through water as well as air, he added that "we must be able to talk not only to ships on the surface, but we must also be able to communicate with the elusive sub- marine and with the planes on their sundry missions in the air." Rear Admiral W. B. Ammon, Director of Naval Communications, explained that the need for the unprecedentedly powerful transmitter had emerged after World War II with recognition that the naval communications system was inadequate to support world- wide naval operations in time of peace. Since many ships, such as submarines and smaller surface craft are unable to carry extensive antenna systems, he said, "reliance must be placed on powerful transmissions to overcome this handicap and to make sure that any forces operating independently or submarines on war patrol receive combat orders and information promptly." The requirements could be best met by a powerful very low frequency broadcast, requiring large and complicated equipment, he said and the result was the beginning of the Jim Creek project. 

Greater Developments Predicted 

Even as the giant transmitter went into operation at the highest power level ever employed in radio communication. General Sarnoff cautioned against any inclination to regard it as the ultimate in communications. More powerful transmitters may yet be built, and better means will be discovered to communicate with the fleet, he said. "When we look at this big structure, we must remember that while its skeleton is concrete, steel and copper, its heart is the electron the tiniest thing in the universe," General Sarnoff said. "For forty-seven years I have lived with the electron, and my experience points to one conclusion: great as the electron's achievements have been, we are still in the horse and buggy era of its development. It is not difficult to visualize the day when the electron will carry sight as well as sound to our armed forces around the world." Already we possess the scientific knowledge to make television world-wide, he said. It is technically possible to circle the globe with a land chain of microwave relay towers, to equip aircraft with relay equipment to form an aerial bridge across an ocean and to lay coaxial cable across the ocean floors to carry both sight and sound internationally. And such advances, he said, "will lead to new uses of the electron for military as well as commercial purposes." 

Details of the Installation 

The background of the dedication ceremony, attended by about 200 naval, industrial and governmental leaders, was a squat, concrete building nestling in the deep valley between steep slopes and roofed by a web of antenna slung between the ridges looming 2700 feet above the valley floor on the north and south. The entire assembly known already to Navy communications men as "Big Jim" is the answer to a set of requirements determined by the Navy's Bureau of Ships and specified in a contract signed with RCA in 1947. The site itself was chosen on the basis of terrain suitable for the massive antenna, access to the electric power of Bonneville Dam, the nearly ideal ground conductivity of the area, relative access to supply lines in contrast to even more remote sites, and security in the event of a war. For six years, in cooperation with Navy experts, the skilled staff of the Engineering Products Department of the RCA Victor Division worked out details and construction of the extremely powerful transmitter while the unique problems of antenna arrangement and assembly were overcome by the specialists of RCA Communications, Inc. The transmitting equipment, manufactured at the RCA Victor plant in Camden, N. J. and transported to Seattle aboard 27 freight cars for trucking into the remote valley over a road cut through by the Navy, occupies most of the two-story concrete building at the heart of the installation. On the ground floor are power transformers, switch-gear, pumps, water tanks, heat ex- changers, telephone cable terminals and shops for servicing the equipment. The transmitter itself actually a combination of two 500,000 watt transmitters Is located on the second floor. Its very low frequency transmission ranges from 14.5 to 35 kilocycles, as compared with the 550 to 1600 kilocycle range of the standard broadcasting band for commercial radio.

Antenna System is Spectacular

The signal goes out over an antenna system that forms the most spectacular feature of Big Jim. This is not the first use of mountains to replace high towers for antenna it has been done before at Haiku, Oahu, and Trinidad, B.W.I. but it is by far the largest and most complicated arrangement of the kind ever undertaken. The ten antenna spans, or catenaries, soar across a space ranging from a little over a mile to a mile and two-thirds from one ridge to the other, forming a zig-zag pattern over the floor of the valley. Twelve 200-foot towers along the crests of the ridges support the heavy spans, the longest of which stretches over an 8,700-foot gap. At the mid-point above the valley, the spans sag as much as 1,063 feet to allow for wind and ice conditions expected in the area, and from the lowest point of each span plunges a cable down to the towers of the system connecting the antenna with the transmitter. The whole antenna system is divided into two sections of five spans each. With the transmitter also divided into two units, this makes possible the operation of one half of the station in case the other half should be out of service for any reason.

The site of the powerful station was selected by the Navy after a careful survey of all possible locations in the Puget Sound area, and the initial measurements, including erection of a single wire 8,000-foot antenna span for test transmission, were characterized by Admiral Ammon at the dedication ceremony as "a story to match any of those in the history of the taming of the West." Before the full system now in operation could be installed, the Navy spent nearly a year clearing thousands of Douglas firs from the valley slopes to facilitate rigging, eliminate the danger of forest fire, and, most important, improve the efficiency of the transmitter. Trees, it appears, absorb large quantities of the energy radiated by the antenna. RCA experts had also to cope with a substantial problem created by the electromagnetic field around the transmitter. The field generates enough electricity to spark across a foot-wide gap, and to ground the system, copper shielding and a ground screen were installed in the transmitter building while more than 200 miles of copper wire were laid in a radial arrangement of buried ground conductors. As an added point, the transmitter building was constructed to resist earthquakes. In operation. Big Jim requires a permanent staff of 4 officers and 70 enlisted men, plus 35 civilian employees. Most of the personnel will live in quarters on the 725- acre site, and the remainder in Arlington, Wash., some 1 1 miles away. The installation will be a relatively self-sufficient community with its own water and sewage disposal system, a completely equipped fire house, and electricity from Bonneville Dam the primary source of power for the transmitter itself.