Base diagrams correspond to the codes in "Base" columns of the tube-data tables. Bottom views are shown throughout. Base connections are abbreviated as follows:
BS - Base Sleeve NC - No Connection F - Filament P - Plate G - Grid PB F - Beam Plates H- Heater S - Shell IC - Internal Connection K - Cathode
Alphabetical subscripts indicate structures in multistructure tubes.
D = diode, P = pentode, T = triode, HX = hexode Subscript CT indicates filament or heater center tap.
Generally, when Pin 1 of a metal-envelope tube (except all triodes) is shown connected to the envelope, Pin 1 of a glass-envelope counterpart (suffix G or GT) is connected to an internal shield.