The 3-400Z or 8163 is a 400 watt dissipation triode designed for zero bias operation. The usable frequency for maximum ratings is 110 MHz. The first example (3-400Z) is an Eimac and the second (8163) was made by Amperex and has a larger diameter anode pin.
Length = 6.38" Diameter = 3.56"
Max voltage = 4000
Max current = 350 ma
Fil voltage = 5
Fil current = 14.6 amps
Data sheet:
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