12B4

The 12B4(A)  (P/N 154-0044-00) is a power triode vacuum tube with a B9A (Noval) miniature 9-pin base. It has 5.5 W maximum plate dissipation, 1000 V peak plate voltage, and and 105 mA peak cathode current.

parallel 12B4s (center left) as pass elements in 585 power supply

The 12B4 is used in the 126, 551, and 555, and as a pass tube in the power supply of the 513, 581 and 585.

The 12B4A (154-0044-00) is similar except for the controlled heater warm-up, suitable for use in conjunction with other 600 mA types.

Data

• 12B4A Datasheet
• 12B4 / 12B4A @ radiomuseum.org

Pictures

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  12B4 Tube