MARCHI

Radio Corporation of America was formed in 1919 through the reorganization of Marconi's American activities. Its early strength lay in combining patents, communications, distribution and commercial control rather than in a single tube factory. In its first years, an important share of the tubes sold under the RCA and Radiotron names were made by General Electric and Westinghouse. An RCA marking therefore identifies the commercial brand with certainty, but does not by itself always identify the plant that made the tube.

Radiotron became the best-known name for RCA tubes and appears on cartons, manuals and advertisements alongside the later RCA Radiotron forms. Cunningham is also part of this history: catalogues place it beside Radiotron and preserve its commercial identity. The purchase of Victor Talking Machine Company in 1929 added the RCA Victor name to the firm's equipment and literature. These names are connected but refer to different roles and periods: the tube brand, company, physical maker and equipment using the tube are not the same thing.

From 1 January 1930 RCA brought its tube work together in RCA Radiotron Company, headquartered at Harrison, New Jersey. Harrison became a principal centre for RCA receiving tubes; the later RCA Manufacturing Company placed the activity within a broader industrial structure. From early receiver valves to tubes for television and professional applications, the RCA range followed the development of American electronics. Radiotron manuals are as much part of the story as the tubes themselves: they record characteristics, application circuits and designations that help place each type in its technical period.