Radio age research, manufacturing, communications, broadcasting, television (1941)

Radio and Electronics—Their Status and Promise {Continued from Page 14) during the early radio days but passed from the scene when the electron tube emerged. Like actors in a play, a place was reserved for them in a later scene. We shall come to that soon but first, we need to examine the electron tube. The electron tube is the lever-arm of radio and elearonics. It is the foundation stone or the keystone of all apparatus and techniques upon which the present ever-expanding industry depends. Industry Built on Electron Tube In its simple form, an electron tube is a device — a vessel devoid of air — m which electrons are boiled out from a metal or cathode material. When freed in the vacuum space, they are subjected to the desired action by a control influence. Through the effect of a small control influence, a larger output effect is pro- duced on the electrons. This output effect is trans- formed in a work circuit so as to do what the designer seeks to achieve. From this simple form we have pro- gressed to a myriad of electron tube types. We have transducers of voltage, current, light, and other mani- festations of energy. Upon this versatile instrument we have built an industry of first magnitude. It is truly a modern version of Aladdin's Lamp. While we have progressed far, and while we are still expanding the versatility and usefulness of electron tubes, attention again has been directed to the discard materials, the semi-conductors. As is so often the case, we find in the discard, the real gem itself. But this time the approach was not through empirical experi- mentation but by painstaking research with understand- ing of each step. Also it was not a single approach but one which has taken many routes with many evidences of current and potential results. This has been termed the electronics of the solid state. The electron tube might be similarly termed electronics in vacuum. The first broad uses of these new materials came from their non-linear and unilateral propenies which were those of importance for radio-frequency detectors of the early days. Then we moved into small powet applications as well. As understanding grew, we learned that conductivity could be influenced by radiant energy (photoconductivity), by electron bombardment (bom- bardment induced conductivity), and by applied voltage (transistors), Just as is the case for the electron tube. Here, however, we are working with the controlled action of electrons in solid materials. Why is this important.' It is important because we have a new tool, a new instrumentality. It promises to augment and to supplement the electron tube. It means new freedoms in the future in the designs of equipment. It means wider and added services and uses. It provides a new dimension. In radio and electronics we view the scene on an approximate sixtieth anniversary and we see a vast panorama of what has been created. These are the cre- ations of scientific and applied research with the dress of ingenious engineering. We see a view which has radiated outward in an ever-expanding fashion. Now as we move to the present and look to the future, we do so with new instrumentalities in hand. We do so with a sound established framework of research and engineer- ing. We see service for which our measuring tapes are too short. The horizon is boimdless. NEW TUBE FOR UHF A new tube m the "pencil-type" series which is capable of producing an output of 1,000 watts in cer- tain types of specialized service, at frequencies up to 3,300 megacycles, has been announced by the RCA Tube Department. The tube, a triode, is distinguished by its small size, light weight and stability. It was specifically designed for service in transponders, navigation beams, telemeters and pulse altimeters, and for use in signal generators and mobile transmitters operating in the UHF region. All metal parts of the tube's envelope, with one exception, are made of silver-plated steel. 26 RADIO AGE