The action of a split-anode magnetron

An investigation has been made of the generation of continuous-wave oscillations by a split-anode magnetron (excluding the ultra-short waves). It has been found that there are two types of oscillation: the first in which the strongest oscillations over a large range of wavelengths are produced by the same set of values of the voltage and field applied, and the second in which each wavelength has a particular set of values of voltage and field for best results, but these sets are different for every wavelength. A simple relation has been found experimentally between the wavelength, field, and voltage, in this latter case. A theory has been developed (not yet complete mathematically) to show that the first results are due to a pure negative-resistance effect, and the latter to a type of amplified negative resistance which involves a resonance. The theory is confirmed by experiments with a valve having four segments in place of two, and with a valve of larger dimensions.