Abstract: A delay line for travelling wave tubes, particularly travelling wave tube whose gain and whose output power are independent of frequency over a plurality of octaves and contain a helix (9) in an electrically conductive cylinder (5). The helix is fixed and adjusted by retaining rods (8). Loading webs (4) are arranged parallel to the axis of the adjoining electrically conductive cylinder (5) and a small gap (12) is left free adjacent the helix (9). The extremely high requirement for mechanical dimensional accuracy and reproducibility of the dimensions in such delay lines are obtained by using loading webs (4) which are integrally formed in the electrically conductive cylinder (5).

Abstract: A circuit assembly for temperature-dependent cathode current tracking in traveling-wave tubes having control electrodes and cathodes with a predetermined cathode current, in combination with a power supply, includes a temperature-dependent network thermally coupled to a given point of the traveling-wave tube for measuring the actual temperature of the tube, and an electronic control circuit in the power supply connected to the temperature-dependent network for keeping the predetermined cathode current substantially constant by varying the voltage at the control electrode of the tube.

Abstract: A traveling-wave tube having a cylindrical vacuum envelope surrounded by a permanent-magnet system of ring-shaped pole washers and magnet rings respectively disposed therebetween and having opposite polarizations alternatingly in axial direction, which includes spacer rings formed of nonmetallic material surrounding the cylindrical vacuum envelope and spacing the magnet rings therefrom, corresponding magnet rings and spacer rings being soldered together into respective strong and stable units.