Radio telephony

This paper is divided into two parts. The first part describes the development of the art of radio telephony by the American Telephone and Telegraph Company and the Western Electric Company to the accomplishment of transatlantic telephony, followed by demonstrations of the use of radio telephony between ships and of methods of connecting radio and wire telephone systems. This first part covers work principally of an engineering research nature, the most important problems being the development of systems of generation, modulation, transmission and reception of radio telephone signals. The second part is concerned almost entirely with the work of producing radio telephone and allied apparatus for the Army and Navy in the late war. The major problem of the second part was the design of light and compact sets which could be produced rapidly and in large numbers, for the main features of the generating, modulating and receiving systems were already well understood.