300B

Name: 300B
Brand: Western Electric

Power Triode — DHT — UX4 — Western Electric

Data: HighHigh quality — base, heater, all universal parameters present, and ≥50% of desirable parameters filled in. Safe to use for design decisions.

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Known Equivalents & Substitutes

WE300B4300A4300BAV300BCV2609HF-300BPX300B

Electrical Specifications

Absolute Maximum

Anode Voltage (max)Plate Voltage (max)400V

Anode Dissipation (max)Plate Dissipation (max)36W

Cathode Current (max)Plate Current (max)100mA

Max Grid ResistorGrid Circuit Resistance (max, self bias)0.25MΩ

Max Grid Resistor

Notes

Rg_max is unusually restrictive: 50kΩ (fixed bias) or 250kΩ (self-bias) — much lower than most power triodes; driver stage design must account for this.
DHT tube: the filament serves as the cathode; there is no heater-cathode isolation.
Pins 1 and 2 are both connected to the plate in the original WE base design, providing two physical contact points for the single anode electrode.

Pin Layout — UX4

1Filament (f-)

2Plate (Anode)

3Grid

4Filament (f+)

Socket-Compatible Tubes ⚠ Not electrically compatible

12A 1641 26 2A3 30 31 3C24 40 45 50 71A 800 8005 801A 816

References