Optimum Load Impedance for Triode Amplifiers Employing Feedback

Burton F. Miller

The apparent plate-resistance of vacuum-tubes employed in inverse feedback amplifier stages is shown to be a function of the degree of feedback employed. Equations for predicting the optimum value of amplifier load impedance for maximum undistorted power output are derived, and the necessity for properly building out the amplifier load circuit is demonstrated. A basic circuit, employing a combination of two feedback elements is indicated, which permits securing the maximum undistorted power output from an amplifier stage while maintaining proper impedance relationships between amplifier and load circuits without the use of building-out resistors.

Print ISSN
Published
1940-08
Content type
Original Research
DOI
10.5594/J10059