Criteria for the Amplitude Stability of a Power Oscillator

Criteria for the amplitude stability of a power oscillator are derived in the form of two inequalities. These inequalities involve derivatives which are computed graphically from the constant current design diagram that is customarily used for power oscillators. In the final form of the inequalities, the derivatives used are of the double logarithmic type: that is the fractional increment of one variable divided by the fractional increment of the other. In addition, the criteria involve the ratio of fed-back power to plate power and the ratio of the time constant of the grid leak and condenser combination to the time constant of the tank circuit. There are also involved certain trigonometric functions of the grid current and plate current angles of flow.