An Improved Telephone Set

HE Bell System is now introducing a new and improved common battery telephone set, intended to supplement the present well known combined set first introduced in 1937.1 · 2 In view of the established merits of the earlier set, of which something like 25,000,000 are now in the plant, it is of obvious interest to point out the nature and magnitude of the improvements represented in the new set which justify the effort and expense of such a change, to discuss some of the factors influencing its introduction at the present time, and to describe the set itself and its characteristics. Before proceeding with this, it is pertinent to define what is meant by an improvement, what sort of changes come under this heading, and what means are available for appraising them. In the Bell System the answers to these questions are looked for in a combination of laboratory and field experience using the effect on service as a major criterion. DESIGN FOR SERVICE Improvements may be classified under two general headings. First, there are changes in form and in technical characteristics which improve the quality of the service and increase the satisfaction of the subscriber; the new design may be more acceptable in appearance, easier and more convenient to handle and manipulate, and provide easier and more natural conversation with less effort. Such factors, however, valuable as they are in themselves, cannot be considered apart from the second important kind of improvement, which is cost reduction.