The Wamoscope - A microwave display device

A microwave tube which gives a direct display of wide-band information on a cathode-ray tube screen is described. In this tube the amplitude modulated microwave signal is fed to a helix of a forward wave traveling wave amplifier. Some of this energy is transferred to the electron beam in such a way as it produces a velocity and current modulation of the beam. Where the collector of a normal traveling wave tube would be, a velocity sorting retarding field electrode system is substituted. This allows a discrete portion of the velocity distribution produced by the microwave energy to pass on to a fluorescent screen. In this manner the wide-band characteristic of the traveling wave tube is combined with a cathode ray tube in the same envelope such that the whole device then is a wide-band display tube. The brightness at the screen is a function of the microwave power input to the tube. The experimental transfer characteristic is shown and explained qualitatively in terms of the basic operating principles of the device.