204933 ⎘
Transit-time tubes, e.g. klystrons, travelling-wave tubes, magnetrons; Magnetrons, i.e. tubes with a magnet system producing an H-field crossing the E-field with an electron space having a shape that does not prevent any electron from moving completely around the cathode or guide electrode having only one cavity or other resonator, e.g. neutrode tubes with interdigital arrangements of anodes, e.g. turbator tube