Max Grid ResistorGrid Resistor (fixed bias, max)0.5MΩ
Typical Operating
Anode Voltage (typical)Plate Supply Voltage200V
Grid 1 Bias VoltageGrid Voltage-2V
Anode CurrentPlate Current7mA
Anode ResistancePlate Resistance (approx.)12,400Ω
TransconductanceTransconductance
Section 2 — Triode No.2 (Medium-Mu)
Absolute Maximum
Anode Voltage (max)Plate Voltage (max)330V
Anode Dissipation (max)Plate Dissipation (max)2W
Max Grid ResistorGrid Resistor (fixed bias, max)0.5MΩ
Typical Operating
Anode Voltage (typical)Plate Supply Voltage200V
Section 3 — Pentode
Absolute Maximum
Anode Voltage (max)Plate Voltage (max)330V
Screen Voltage (max)Screen Voltage (max)330V
Anode Dissipation (max)Plate Dissipation (max)4W
Max Grid ResistorGrid Resistor (fixed bias, max)1MΩ
Typical Operating
Heater
Heater VoltageHeater Voltage6.3V
Heater CurrentHeater Current1.05A
Notes
The 6AF11 is pin-identical (12DP basing) with the same triode characteristics, but has a higher-rated pentode section (Pa_max=5W vs 4W, Ps_max=1.25W vs 1.1W for Vg2≤165V) and slightly lower triode No.1 Pa_max (1.1W vs 1.5W). The 6AF11 can substitute for the 6BD11 in all standard applications.
The dual triode has a high-mu (μ=68) unit (Triode No.1) and a medium-mu (μ=41) unit (Triode No.2) in a single envelope — not two identical triodes.
Pin 7 serves as Cathode of Triode Unit No.2 and Internal Shield; Pin 9 serves as Pentode Cathode, Pentode Grid No.3, and Internal Shield — both are shared internal connections.
Pentode Grid-No.2 max input: 1.1W for Vg2 up to 165V; higher voltages require consulting the Grid-No.2 Input Rating Chart.
Heater-to-cathode voltage: max 200V peak (heater negative); max 200V peak / 100V DC (heater positive).