The Magnetron Amplifier and Power Oscillator

As an introduction, details of tube design are discussed, together with a partial list of the sizes studied. A resume of the general theory of magnetic control is then given. The first part of the paper is taken up with the application of the magnetron as an amplifier at 8,000 meters wave length. The circuit is described and the results of tests on tube impedance, design of control coils, the variation of amplification with anode voltage, design of polarizing field coils, and description of a four-stage amplifier are given. The second part is concerned with the use of the magnetron as a generator. Since the magnetron is a rather unfamiliar tube, the circuit and necessary apparatus are described in considerable detail. The conditions necessary for efficient operation are then discussed. Based on observed wave shapes of anode voltage and anode, current, formulas suitable for circuit design are developed, and the complete calculation of a typical circuit given. The results of tests at various voltages are then compared with calculated performance and representative oscillograms shown. In conclusion, a few factors which may cause departure from theoretical results are briefly discussed.