Abstract: A modulated bunched electron beam incident on the inner conductor 16 of a coaxial structure launches TEM waves that are distributed to multiple radial waveguides 22 around the outer conductor 14 of the coaxial structure. A tuning piston 32 may be moved axially within the outer conductor for matching the impedance of the coaxial structure to the waveguide array.

Abstract: An improved color picture tube has an inline electron gun for generating and directing three electron beams, a center beam and two side beams, along coplanar paths toward a screen of the tube. The gun includes a main focus lens for focusing the electron beams. The main focus lens is formed by two spaced electrode members each having three separate inline apertures therein. Each electrode also includes a peripheral rim. The peripheral rims of the two electrodes face each other. The apertured portion of each electrode is within a recess set back from the rim. The width of the recess in at least one of the electrodes is wider at the side beam paths than at the outer beam path, measured perpendicular to the plane containing the electron beam paths.