Abstract: A magnetron assembly that is adapted to be mounted on a wall of a waveguide in a microwave oven includes a yoke enclosure in which is disposed a magnetron tube. The yoke enclosure is generally U-shaped with an open top end and open opposite ends to permit air flow through the yoke enclosure and past circular disc shaped cooling fins that are affixed only to an anode assembly about the magnetron tube. Different configured mounting plates can be detachably disposed in the open top end of the yoke enclosure. A filter box has input power terminals for the magnetron tube extending therefrom and is mounted with respect to a bottom wall of the yoke enclosure such that the yoke enclosure can be rotated to various positions relative to the input terminals extending from the filter box.