A novel technique and mechanism for winding precision helices for traveling-wave tubes

A process and accompanying mechanism is described whereby helices for a traveling-wave tube are made with a total pitch variation of (maximum minus minimum reading, turn to turn readings are within .0004"). The procedure whereby the helix is then glazed to synthetic sapphire rods for ruggedization is also described. The helix winding technique is general and can be easily applied to tape helices as well as wire. The system is self-consistent in that any arbitrary pitch can be specified with only a minor corresponding adjustment in the winding mechanism. The tolerances quoted represent those obtained to date; however, it is expected that further refinements can bring the accuracy to .