Anode Voltage (typical)Plate Voltage (Class C)2,000V
Grid 1 Bias VoltageGrid Bias (Class C)-340V
Anode CurrentPlate Current (Class C)210mA
Amplification Factor (μ)Amplification Factor15.5—
Output
Output PowerOutput Power (Class C)300W
Heater
Heater VoltageFilament Voltage5V
Heater CurrentFilament Current10.5A
Notes
The VT127A is the military designation for the Eimac 100TS (also designated 3-100D2). Used in WWII SCR-268 radar as a ring oscillator.
No standard socket base — connections are made via external rods protruding through the glass envelope: two top rods (plate, in parallel), two middle rods (grid, in parallel), two bottom rods (filament).
Class C operating data: Va=2000V, Ia=210mA, Vg=-340V, Pout≈300W. These are transmitter/RF amplifier conditions, not audio operating points.
Maximum plate dissipation is 100W continuous. For audio Class A use, plate voltage and current must be derated accordingly.
Transconductance (gm) and plate resistance (ra) not found in available sources; only mu=15.5 is confirmed. ra can be approximated as mu/gm when gm is measured at the operating point.