Some Notes on Vacuum Tubes

The value of the exponent connecting plate current and plate and grid potentials is experimentally investigated for a number of tubes. It is found to be markedly different for different tubes, and for the same tube at different plate voltages. Particularly is this the case for low plate voltage tubes. After discussing briefly distortion in amplifying tubes, the capacity and conductance within tubes is considered. Experimentally determined data governing these quantities are given, these being obtained on a carefully designed radio frequency Wheatstone bridge. An experiment on the detecting action of a tube without grid condenser seems to prove that grid-to-filament circuit asymmetry of characteristic is not responsible for the detecting action.