6BA6

Name: 6BA6
Brand: RCA

Small Signal Pentode — B7G — RCA

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

EF93CV454W7275749 6BD6

Similar Tubes (Not Drop-In Compatible)

6AU6

Sharp-cutoff version with same pinout — not suitable where variable-mu (AGC) operation is required

6BA6W

Ruggedised military version — electrically identical, different mechanical construction

Electrical Specifications

Absolute Maximum

Anode Voltage (max)Anode Voltage (max)330V

Screen Voltage (max)Screen Voltage (max, supply)330V

Anode Dissipation (max)Anode Dissipation (max)3.4W

Screen Dissipation (max)Screen Dissipation (max, Vg2 up to 165V)0.7W

Notes

Remote-cutoff (variable-mu) characteristic: transconductance varies smoothly with grid bias, enabling AGC control without cross-modulation distortion.
Grid No.3 (suppressor) is connected to cathode at the socket — external connection required.
RCA specifies two operating conditions: Va=100V/Vg2=100V (Ia=10.8mA, gm=4.3mA/V) and Va=250V/Vg2=100V (Ia=11mA, gm=4.4mA/V).
Cathode bias resistor Rk=68 Ω for the standard operating point.
Brimar rates Vg2_max at 125 V for the operating condition, while RCA allows Vg2_supply up to 330 V — consult specific manufacturer data for your application.
Vhk_max is 200 V (both polarities, but DC component must not exceed 100 V when heater is positive).

Pin Layout — B7G

1Control Grid (g1)

2Suppressor Grid (g3) + Internal Shield

3Heater

4

Socket-Compatible Tubes ⚠ Not electrically compatible

EF91 EF94 HF94 XF94

References

https://frank.pocnet.net/sheets/049/6/6BA6.pdf