Resonant lines for frequency control

Vacuum tube oscillators for radio frequency signals above 25 megacycles may be controlled with a high degree of precision by resonant lines, and at lower frequencies may be used to obtain a larger power output than is obtainable from crystal oscillators. The general principles of the design of concentric conductor lines and means for compensating temperature changes are discussed in this paper. Line controlled oscillators may be used with frequency multipliers, or to control oscillators at lower frequencies.