Transmission and Reception of Centimeter Waves

Apparatus is described consisting of a new type split-anode magnetron, which has been used to generate 2.5 watts of energy at 9 centimeters wavelength, with an efficiency compared to direct-current plate dissipation of 12 per cent. The methods used for measuring the tube output energy and the radiated energy are explained. Measurements of attenuation made with this apparatus up to distances of 16 miles line-of-sight through air indicate that an inverse distance law for field strength is obeyed. Modulation of the waves by means of variation in the transmission of an ionized gas is described. A summary is given of some experiments which have been made using rectifying crystals, positive grid tubes, and magnetrons as centimeter wave detectors.