Radio Broadcast (May 1928-Apr 1929)

Dr. Alfred N. Goldsmith manipulating a special remote-control amplifier for broadcast transmission ment was the fact that 2xn's programs were actually reaching a large part of the country. One of its regular listeners was Dr. A. Hoyt Taylor, then at the University of North Dakota at Grand Forks, N. D., and now in charge of the Naval Communication Laboratories near Washington. First Remote-Control Station A NOTHER distinction which this early broadcasting station possessed is that it was the scene of the first experiments in remote-control broadcasting. As a convenience, Dr. Goldsmith arranged an outlet for the telephone circuit so that he could call the college from his home on lower Fifth Avenue, have the telephone receiver at the college connected with the broadcasting transmitter, and thus broadcast from uptown on Morningside Heights, while listening to his own voice returning by radio. In the pressure of work. Dr. Goldsmith evidently had not read his contract with the telephone company and presumably the company was in ignorance of these early experiments. Thus identified with the first remote-control broadcasting and the first long-range broadcasting, it is interesting to observe that Dr. Goldsmith also took part in the first public demonstration of radio picture reception, broadcast from a general broadcasting station and received in his home. There had been previous instances of picture broadcasting from wjy, wgy, and wor but, in connection with none of these, was the reception publicly conducted. Out of the original experiments in remote-control radio telephony has grown a nationwide, wire-interconnected, broadcasting system, operated under the technical supervision of Dr. Goldsmith. Thus, the first prophecy of his conception of radio service, namely the vocal appearance, is now transferable instantaneously through any terrestrial distance. He now awaits accomplishment of the second and the progress made is a matter of public record. There have been some recent additions to Dr. Goldsmith's laboratory building and, on my most recent visit, he offered to show me the new facilities. But he first paused for a moment in the reception room to find a waiting friend to accompany us. The friend proved to be a bright-eyed youngster of twelve, who strode with us in silent amazement through the upper floors of the laboratory. Here an entire floor of new testing equipment had been installed to measure the operating characteristics and life of alternatingcurrent tubes which are now being manufactured in large quantities. There are facilities for testing 18,000 tubes simultaneously and the power required to furnish the plate current for these tests is 400 kilowatts! The power used in heating the filaments of these tubes is 240 kilowatts. So great is the heat dissipated by the tubes under test that a special ventilating system is necessary which pumps a complete renewal of air into the test room every three minutes. Other Testing Equipment A LTHOXJGH many specialized lines of ■L^ radio and acoustic research and development are carried on at this laboratory, the greater part of its facilities are devoted to exacting testing of the Radio Corporation's commercial products. A percentage of the output of all the factories contributing to the RCA fine is sent here for test. Under the most elaborate and systematized scrutiny, the constants and life of tens of thousands of vacuum tubes annually are determined and the uniformity of their performance maintained. Receiving sets are likewise tested for every factor which determines their ultimate reliability and service to the user. One amazing device automatically plots an audiofrequency response curve and writes an infallible record of its fidelity of reproduction without the influence of human judgment. Extensive original work in circuit design and reproducer development is also conducted under Dr. Goldsmith's direction. The theory, design, and operation of both receiver test equipment and vacuum-tube production testing was described in the November, 1928, Proceedings, Institute of Radio Engineers, in papers entitled "Quantitative Methods Used in Tests of Broadcast Receiving Sets" and "Vacuum Tube Production Tests," both by A. F. Van Dyck and F. H. Engel of the Technical and Test Department of the Radio Corporation of America. Walking through this laboratory and listening to Dr. Goldsmith's explanation of the purpose of the major experiments taking place, accompanied by the young enthusiast, reminded me of a day, some fifteen years ago, when I, at about the same age, had walked through Dr. Goldsmith's laboratory at the College of the City of New York. Indeed, it was that visit which confirmed my conviction that radio would always be both my work and my hobby. But it is no peculiar distinction to have been wedded to the radio art by Dr. Goldsmith. In Dr. Goldsmith's office are many mementoes of his career, ranging from autographed photographs from Marconi, Steinmetz, and Einstein to a significant radio emblem from the sculptor Edward Field Sanford, Jr., made for Dr. Goldsmith. But none of these seems closer to him than a bronze plaque, given him by the five students of the first radio engineering course which he conducted at the College of the City of New York. One of the names I noticed was that of J. D. R. Freed, now President of the Freed-Eisemann Company, another Carl Dreher, until recently staff engineer of the National Broadcasting Company, now Chief Engineer of RCA Photophone • february, 1929 . . . page 228 •