Resonant Impedance and Effective Series Resistance of High-Frequency Parallel Resonant Circuits

The writer has already published in a previous issue of the PROCEEDINGS a new method of measuring resonant impedance and radio-frequency resistance as applied to broadcast frequencies. In the present paper he gives, as another example of its application, some results obtained from the measurement in a band of high frequencies extending from 6300 to 26,300 kilocycles. It is ascertained that the additional dielectric loss, which is introduced into the resonant circuit by using a screen-grid tube as a dynatron, exercises only a slight influence on the measurement. The constants of the resonant circuit alone may be derived from those of the circuit combined with the tube, which can be measured directly. The correctness of the result is varified by the aid of a known value of the additional series resistance. Finally some remarks on short-wave amplification are given as a result of measurements.