Millimeter dual helix traveling-wave tube

Assembly and brazing of gun structures has resulted in two complete gun assemblies. The fixturing produced close tolerances needed for the small gun sizes. A barrel assembly complete with pole pieces has been brazed and awaits a final sizing broach. Problems with the initial broach were solved by fabricating the barrel sections by milling, brazing and final machining. Several RF circuits have been laser welded, copper coated and brazed. One circuit is complete with six attenuated support rods attached ready to heat shrink. The use of a stripline in conjunction with a two section quarter wave transformer has produced a good match over the band.