Abstract: A vertical deflection system for a CRT is disclosed which has a pair of traveling wave deflectors disposed opposite each other across a path of beam from gun to target. Each deflector has a helical conductor in the for of a strip of sheet metal coiled around an elongate core of insulating material. For the provision of a CRT capable of handling a wide band of frequencies, the dispersion characteristic of each traveling wave conductor is optimized through adjustment of the specific dielectric constant of the insulating core. Preferred values of the specific dielectric constant are specified in relation to the characteristic impedance of the traveling wave conductor.

Abstract: A traveling-wave deflection system comprising a pair of deflectors disposed opposite each other across the path of an electron beam from an electron gun to a screen in a cathode-ray tube. Each deflector has a helical conductor wound around a core structure generally extending along the beam path. If made solely of an insulating material as in the prior art, the core structures would be electrified in use of the CRT, with the consequent deflection defocusing and bright line displacement. Therefore, in order to avoid electrification, the core structures are each enveloped in an antielectrification layer of a conducting material having a higher resistivity than the helical conductor. An embodiment is also disclosed wherein the core structures are wholly of conductive material.