Abstract: A cutter, for cutting various surfaces having various curvatures, having a blade assembly and a housing. The blade assembly includes a first blade and a second blade, each having an inner edge and an outer edge, and a guide mounted between the first blade and second blade adjacent to the inner edges thereof. The first blade has a first cutting surface and the second blade has a second cutting surface which are each oriented toward the guide. The first cutting surface is convex toward the guide and the second cutting surface is concave toward the guide, wherein the user may cut concave or convex surfaces by selectively using one of the blades.

Abstract: Lossy slabs are provided in linear-beam tubes such as coupled-cavity TWTs and klystrons to produce a more level tube response over its full operating band, and to eliminate oscillations at the upper cut-off frequency in the TWTs. The slab thicknesses are selected to produce a substantially non-resonant field of about one-quarter wavelength within the slab when the tube is operated within its passband. The slabs are formed from a dielectric material with a conductive mixture of at least about 15%.

Abstract: In a travelling-wave tube (20), a cylindrically-shaped slow-wave circuit cavity-defining member (34) is supported by and is thermomechanically bonded to a tubularly-configured vacuum wall member (32). The bonded joint comprises a pair of arcuate grooves (52) extending lengthwise of the slow-wave circuit and positioned diametrically opposite one another about the axis of the tube. A helical or wavy spring (54, 58) lies in each groove and is resiliently biased in intimate mechanical and thermal contact between the groove and the vacuum wall. The helical spring, in particular, can be used as a conduit for exhaust of gases from the travelling-wave tube during its fabrication.