12G4

Small Signal Triode — B7G

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

↗ TDSL ↗ Radiomuseum

Known Equivalents & Substitutes

12H4

Similar Tubes (Not Drop-In Compatible)

12J5GT

Electrically identical but Octal base — not pin-compatible

6J5

Electrically identical but 6.3 V heater — not interchangeable in series-heater strings

Electrical Specifications

Absolute Maximum

Anode Voltage (max)Anode Voltage (max)300V

Anode Dissipation (max)Anode Dissipation (max)2.5W

Typical Operating

Anode Voltage (typical)Anode Voltage (typical)250V

Grid 1 Bias VoltageGrid Voltage-8V

Notes

Brans Vademecum lists this with 12AU7 family equivalents, but these are NOT pin-compatible drop-in replacements — only functionally similar single triodes.
Same characteristics as the 12J5GT per RCA data.
Sams substitution guide lists 12H4 as a substitute.

Pin Layout — B7G

1Anode

2Control Grid

3Cathode

4

References