A Graphical Method to Find the Optimal Operating Conditions of Triodes as Class C Telegraph Transmitters

The oscillation of a triode can be characterized by plate-supply voltage, swing of plate voltage, peak plate current, and angle of current flow. For medium-size transmitters it is economical to draw as much output power as consistent with the ratings of the tube. A graph has been plotted with the swing of plate voltage and peak plate current as co-ordinates showing the output and necessary bias if the plate-supply voltage is held at the rated value and the angle of plate-current flow is chosen to produce just the rated dissipation. Grid resistor, grid current, and grid dissipation can be established from another graph. All data are given in ratios applicable to any type of tube.