The neotron - An ultra low distortion single side-band tube

The Neotron tube represents a significant step forward in the development of low distortion single-sideband tubes. This paper will discuss the rather outstanding single-sideband capabilities of the Neotron, and will include a brief description of the tube, the principles behind its operation and the theoretical reasons for its low disiortion characteristics. The ideal tube, would seem to be one which is quadratic in the area around cut-off, changing to linear at higher levels. This allows the zero signal bias to be set near the center of the quadratic portion. Thus at low levels the signal would be in the quadratic area, and at high levels cross over into the linear area. In this manner zero signal current would be kept low for good efficiency while maintaining low IM distortion. A characteristic curve of this type is obtained in the Neotron through the use of controlled dynamic variation of cathode emitting area.