The Philosophy and Evolution of New Generation Horizontal Deflection Amplifier Tubes

Abstract

In summary, basic design considerations and performance records show that we should NOT design horizontal deflection amplifiers just with one characteristic in mind. To attempt high cathode current per unit area of the cathode coating results in more remote grid control, therefore, requiring greater grid drive. Due to the very high voltages encountered, spacings are very critical for a tube as large as most horizontal deflection tubes are. Therefore, to design very long structures, with the probable difficulties in spacing accuracy is a move in the wrong direction. To squeeze down spacings of elements generally, then raise plate pulse voltages several kilovolts, is again not a good answer. While it appears that a cavity trap structure is best for present needs, and forseeable future needs, one singlekind, dimensionally, probably will not be an across the board answer. There will be still a need for several different types. If future horizontal deflection tubes can be designed with some of these concepts in mind, the reliability will increase substantially, and the cost held reasonable. If the designers of horizontal circuitry can see some of the problems involved, perhaps they can consider the results of a circuit change or design, thereby, increasing the reliability of the entire deflection system. As an example, to have the load line excessively far to the left will force tube design in the direction of too low a knee which will run the screen current higher hence less reliability as was explained earlier.