{"type_number":"6BD11","canonical_url":"https://tubeofile.com/tubes/6BD11","manufacturer":"RCA","tube_type_key":"compound","tube_type_display_name":"Compound (multi-section)","base_name":"Duodekal","description":"Dual triode–sharp-cutoff pentode compound tube in a 12-pin Duodecar envelope. The dual triode section contains one high-mu (μ=68) and one medium-mu (μ=41) triode unit. Designed for AM/FM radio and TV receiver service. Indirectly heated, coated unipotential cathodes.","is_directly_heated":false,"completeness":"high","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)."],"references":["https://frank.pocnet.net/sheets/049/6/6BD11.pdf","https://tdsl.duncanamps.com/show.php?des=6BD11"],"source_urls":{"r_type":null,"tdsl":"https://tdsl.duncanamps.com/show.php?des=6BD11","radiomuseum":"https://www.radiomuseum.org/tubes/tube_6bd11.html"},"raw_equivalents":["6AF11"],"equivalents":[{"type_number":"6AF11","equivalence_type":"direct","notes":null}],"similar":[],"pins":[{"pin_number":"1","function":"Heater","function_code":"h","notes":null},{"pin_number":"2","function":"Pentode Plate","function_code":"a","notes":null},{"pin_number":"3","function":"Grid of Triode Unit No.2","function_code":"g1_2","notes":null},{"pin_number":"4","function":"Plate of Triode Unit No.2","function_code":"a2","notes":null},{"pin_number":"5","function":"Cathode of Triode Unit No.1","function_code":"k1","notes":null},{"pin_number":"6","function":"Grid of Triode Unit No.1","function_code":"g1_1","notes":null},{"pin_number":"7","function":"Cathode of Triode Unit No.2, Internal Shield","function_code":"k2","notes":null},{"pin_number":"8","function":"Plate of Triode Unit No.1","function_code":"a1","notes":null},{"pin_number":"9","function":"Pentode Cathode, Pentode Grid No.3, Internal Shield","function_code":"k","notes":null},{"pin_number":"10","function":"Pentode Grid No.2 (Screen)","function_code":"g2","notes":null},{"pin_number":"11","function":"Pentode Grid No.1 (Control)","function_code":"g1","notes":null},{"pin_number":"12","function":"Heater","function_code":"h","notes":null}],"specs":[{"key":"Vh","display_name":"Heater Voltage","value":"6.3","numeric_value":"6.3","unit":"V","param_group":"heater"},{"key":"Ah","display_name":"Heater Current","value":"1.050","numeric_value":"1.05","unit":"A","param_group":"heater"}],"sections":[{"section_number":1,"section_label":"Triode No.1 (High-Mu)","tube_type_key":"small_signal_triode","specs":[{"key":"Va_max","display_name":"Anode Voltage (max)","value":"330","numeric_value":"330","unit":"V","param_group":"absolute_max"},{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"1.5","numeric_value":"1.5","unit":"W","param_group":"absolute_max"},{"key":"Rg_max","display_name":"Max Grid Resistor","value":"0.5","numeric_value":"0.5","unit":"MΩ","param_group":"absolute_max"},{"key":"Va","display_name":"Anode Voltage (typical)","value":"200","numeric_value":"200","unit":"V","param_group":"typical_operating"},{"key":"Vg","display_name":"Grid 1 Bias Voltage","value":"-2","numeric_value":"-2","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"7","numeric_value":"7","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"12400","numeric_value":"12400","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"5.5","numeric_value":"5.5","unit":"mA/V","param_group":"typical_operating"},{"key":"mu","display_name":"Amplification Factor (μ)","value":"68","numeric_value":"68","unit":"—","param_group":"typical_operating"}]},{"section_number":2,"section_label":"Triode No.2 (Medium-Mu)","tube_type_key":"small_signal_triode","specs":[{"key":"Va_max","display_name":"Anode Voltage (max)","value":"330","numeric_value":"330","unit":"V","param_group":"absolute_max"},{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"2","numeric_value":"2","unit":"W","param_group":"absolute_max"},{"key":"Rg_max","display_name":"Max Grid Resistor","value":"0.5","numeric_value":"0.5","unit":"MΩ","param_group":"absolute_max"},{"key":"Va","display_name":"Anode Voltage (typical)","value":"200","numeric_value":"200","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"9.2","numeric_value":"9.2","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"9400","numeric_value":"9400","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"4.4","numeric_value":"4.4","unit":"mA/V","param_group":"typical_operating"},{"key":"mu","display_name":"Amplification Factor (μ)","value":"41","numeric_value":"41","unit":"—","param_group":"typical_operating"},{"key":"Rk","display_name":"Cathode Resistor (self-bias)","value":"220","numeric_value":"220","unit":"Ω","param_group":"typical_operating"}]},{"section_number":3,"section_label":"Pentode","tube_type_key":"sharp_cutoff_pentode","specs":[{"key":"Va_max","display_name":"Anode Voltage (max)","value":"330","numeric_value":"330","unit":"V","param_group":"absolute_max"},{"key":"Vg2_max","display_name":"Screen Voltage (max)","value":"330","numeric_value":"330","unit":"V","param_group":"absolute_max"},{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"4","numeric_value":"4","unit":"W","param_group":"absolute_max"},{"key":"Rg_max","display_name":"Max Grid Resistor","value":"1","numeric_value":"1","unit":"MΩ","param_group":"absolute_max"},{"key":"Va","display_name":"Anode Voltage (typical)","value":"135","numeric_value":"135","unit":"V","param_group":"typical_operating"},{"key":"Vg2","display_name":"Screen Voltage","value":"135","numeric_value":"135","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"17","numeric_value":"17","unit":"mA","param_group":"typical_operating"},{"key":"mAg2","display_name":"Screen Current","value":"4","numeric_value":"4","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"45000","numeric_value":"45000","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"10.4","numeric_value":"10.4","unit":"mA/V","param_group":"typical_operating"},{"key":"Rk","display_name":"Cathode Resistor (self-bias)","value":"100","numeric_value":"100","unit":"Ω","param_group":"typical_operating"}]}],"synced_at":"2026-04-07T12:17:33.793Z"}