Several important inventors--among them Vladimir Zworykin, Philo Farnsworth, and John Logie Baird--played key roles in the development of television . After these pioneers laid the foundation, new inventors arrived to expand the field of television, some by making it more practical, and some by refining the new medium's gadgetry. A strong competition emerged between Columbia Broadcasting System (CBS) and the Radio Corporation of America (RCA), which were vying to debut the first practical color television system. With the help of a Swedish immigrant, Ernst Alexanderson, RCA developed the modern system of color broadcasting in 1955. After completing his graduate studies at the Royal Institute of Technology in Stockholm, Sweden, Alexanderson came to the United States in 1901. The following year he secured a job at General Electric (GE), where he designed a high-frequency alternator to be used in broadcasting experiments. Using Alexanderson's alternator, Reginald Aubrey Fessenden made the first transmission of voice over radio waves. Impressed with Alexanderson, the Radio Corporation of America (RCA) hired him as their chief engineer in 1919. Over the next ten years he transmitted the first transatlantic facsimile, invented a home television receiver, and demonstrated a working television system which included a camera and transmitter as well as a projector that showed the picture on a theater screen. When Alexanderson retired from GE in 1948 he had intended to serve only as a consultant. However, in 1952 RCA approached him once again. Their goal was to develop a practical system for broadcasting color television before CBS and their electrical wizard Peter Goldmark could finish their own. Alexanderson agreed to take on the challenge. After several failures, the RCA team introduced a system that not only produced a good color image on new sets, but was compatible with existing black-and-white televisions. CBS's system, on the other hand, could not be received at all by existing sets. Alexanderson continued to work as a television consultant until his death in 1975. During his life he was awarded more than 300 patents.