12X4

Rectifier — B7G

Known Equivalents & Substitutes

No known equivalents. If you know of any, use the ⚑ Report Issue button above.

Similar Tubes (Not Drop-In Compatible)

Electrically identical but 6.3V/0.6A heater — not a drop-in in 12.6V heater circuits

EZ90

European designation for the 6X4 (6.3V heater) — not a drop-in in 12.6V circuits

Electrical Specifications

Absolute Maximum

Anode Voltage (max)AC Plate-Supply Voltage per Plate (max RMS, choke-input)450V

Heater-to-Cathode Voltage (max)Heater-to-Cathode Voltage (max, heater negative)450V

Rectifier

Peak Inverse VoltagePeak Inverse Plate Voltage1,250V

Voltage Drop (typical)Tube Voltage Drop (at Ib=70 mA DC per plate)22V

Max C-input Filter CapacitorMax C-input Filter Capacitor40µF

DC Output Current (max)DC Output Current (max)70mA

Peak Anode Current (surge)Steady-State Peak Plate Current per Plate

Heater

Heater VoltageHeater Voltage12.6V

Heater CurrentHeater Current0.3A

Notes

12.6V heater version of the 6X4. Heater current is 0.3A at 12.6V (vs 0.6A at 6.3V for the 6X4). Same heater power, different voltage/current ratio.
Developed primarily for vibrator power supplies in automobile radios where a 12.6V heater supply is available from the vehicle battery.
GE Essential Characteristics confirms 12.6V/0.3A heater, B7G (5BS) basing, full-wave rectifier service.
Rectifier reference gives Vdrop=22V at rated DC output, max DC output 90 mA, max AC voltage 360V RMS.
Maximum ratings with capacitor-input filter: AC plate-supply voltage per plate 325V RMS at 70 mA. With choke-input: 450V RMS at 70 mA.
Brans Vademecum groups the 12X4 with the 6X4/EZ90 family across multiple base types.

Pin Layout — B7G

1Plate 2 (Anode 2)

2No Connection

3Heater

Socket-Compatible Tubes ⚠ Not electrically compatible

References

245mA

Min Series Resistance (C-input)Min Total Plate-Supply Resistance per Plate (C-input)525Ω

Heater

5No Connection

6Plate 1 (Anode 1)

7Cathode