Method of installing a mount assembly in a multi-beam cathode ray tube

A bulb assembly, including a faceplate panel portion, and a mount assembly, comprising a stem and a multi-beam electron gun assembly, are positioned in axial alignment on respective central longitudinal axes. A reference plane which contains the central longitudinal axis of the bulb assembly and a major axis of the panel portion, is established. An orientation plane is then defined with reference to the structure of the electron gun assembly. The orientation plane is parallel to the central longitudinal axis of the mount assembly and includes two reference points on the structures of the electron gun assembly. The mount assembly is then rotated with respect to the bulb assembly on the coincident longitudinal axes until the orientation plane is at a prescribed angle with respect to the reference plane as optically indicated by the relative position of the two reference points with respect to each other. Then, while maintaining this rotational orientation, the mount assembly is axially moved within the bulb assembly to a desired longitudinal location with respect to the faceplate panel portion. The bulb assembly and mount assembly are then permanently assembled.