English Electric Valve Company Limited

David H Cottey

Brian F Cooper

Peter Robert Davis

A millimeter coupled cavity travelling wave tube has each of its slow wave structures formed of at least one longitudinally extending member having holes made therethrough by a hobbing process, which holes constitute at least in part the cavities of the slow wave structure. In a preferred embodiment a one and one only such longitudinally extending member is provided, the holes therein each a whole cavity. The hobbing is such that a buttress is left outstanding from each cavity facing surface of a cavity separating wall and the beam hole is bored axially through said member from end to end through said buttresses. After machining of the cavity coupling holes in the cavity separating walls (e.g. by spark erosion) the cavities are closed by plates brazed to opposite faces of the member.

Method for manufacturing coupled cavity travelling wave tubes

A millimeter coupled cavity travelling wave tube has its slow wave structures formed by a hobbing process. In a preferred construction, each slow wave structure is made of two individual halves each extending for the length of the structure. Each half contains one half of each cavity and one half of each beam hole and all of the portions of cavity and portions of beam hole in each half are formed in one hobbing operating. Coupling holes between cavities are formed where required by a process (e.g. spark erosion) separate from hobbing and if ferrules or drift tubes are required to extend out of the cavity separating walls in the finished tube, the beam coupling holes are made oversized and individual ferrules are brazed into position. The two halves of the slow wave structure are united by furnace brazing.

Growing community of inventors

East Hanningfield, United Kingdom

David H Cottey