Double-tuned output circuit for high power devices using coaxial cavity resonators

摘要

Coaxial, one-quarter wavelength resonant primary and secondary resonators are employed in conjunction with a tetrode tube to provide, for example, 55 Kw (kilowatts) of output power for VHF, high-band television broadcasting. Coupling between the two resonators is accomplished by connecting an inductance between the center conductors of the resonators. The effective inductance of this connection is varied (and thus the coupling of the resonator circuits is also varied) by the addition of a variable capacitor in series with the inductive connection.