Stability Conditions in Vacuum Tube Circuits
Abstract
Condition for Sustained Oscillations in Vacuum Tube Circuits.After reviewing the fundamental requirements for such oscillations in any three electrode vacuum tube circuit, the fundamental equation for the plate current of a tube with a linear voltampere characteristic: i_{p}=(v_{p}+μv_{g}) R_{0} is differentiated, dv_{p}di_{p} is put equal to the load resistance in the plate circuit R_{2}, and thus the equation: μ=(I+R_{0}R_{2})dv_{p}dv_{g} is obtained as a general relation between the constants of any oscillating circuit: R_{2}, the internal resistance of the platefilament path R_{0}, the amplification constant μ and the derivative of the plate voltage with respect to the grid voltage. This expression is evaluated for five standard types of circuit: Hartley, Colpitts, Meiszner, tunedplate and tuned grid; and it is experimentally verified for the first two.
 Publication:

Physical Review
 Pub Date:
 March 1921
 DOI:
 10.1103/PhysRev.17.302
 Bibcode:
 1921PhRv...17..302D