{"type_number":"6F6","canonical_url":"https://tubeofile.com/tubes/6F6","manufacturer":"RCA","tube_type_key":"power_pentode","tube_type_display_name":"Power Pentode","base_name":"Octal","description":"Power-amplifier pentode of the all-metal type for use in the audio-output stage of AC receivers. Capable of giving large power output with relatively small input voltage. Octal-base version of the type 42; electrically identical to types 42 and 2A5 except for heater ratings. Introduced 1935.","is_directly_heated":false,"completeness":"high","notes":["Electrically identical to type 42 (6-pin base) and type 2A5 (6-pin base, 2.5 V heater) except for heater ratings and base.","Grid-No.1 circuit resistance: 0.1 MΩ max for fixed-bias, 0.5 MΩ max for cathode-bias.","The 6F6-G (ST glass) and 6F6-GT (tubular glass) envelopes have identical electrical ratings to the metal 6F6.","RCA AN-52 (1935) documents Class AB push-pull triode connection of type 6F6, achieving up to 18.8 W output."],"references":["https://frank.pocnet.net/sheets/028/6/6F6.pdf","https://frank.pocnet.net/sheets/127/6/6F6.pdf","https://www.one-electron.com/Archives/RCA/RCA-AppNotes/RCA%201935%20AN-52%20Class%20AB%20Operation%20of%20Type%206F6%20Tubes%20Connected%20as%20Triodes.pdf"],"source_urls":{"r_type":"https://www.r-type.org/exhib/aaa0214.htm","tdsl":"https://tdsl.duncanamps.com/show.php?des=6F6","radiomuseum":"https://www.radiomuseum.org/tubes/tube_6f6.html"},"raw_equivalents":["6F6-G","6F6-GT","42","2A5","CV1076","VT-66","1611","1613","6F6MG","CV1912","12C","6F6S","6F6M"],"equivalents":[{"type_number":"6F6S","equivalence_type":"direct","notes":null}],"similar":[{"type_number":"6K6GT","reason":"Same octal base and pinout, similar power pentode but lower Pa_max (8.5W vs 10.5W) and slightly different characteristics","has_detail_page":false}],"pins":[{"pin_number":"1","function":"No Connection (shell on metal type)","function_code":"nc","notes":null},{"pin_number":"2","function":"Heater","function_code":"h","notes":null},{"pin_number":"3","function":"Anode (Plate)","function_code":"a","notes":null},{"pin_number":"4","function":"Screen Grid (g2)","function_code":"g2","notes":null},{"pin_number":"5","function":"Control Grid (g1)","function_code":"g1","notes":null},{"pin_number":"6","function":"No Connection","function_code":"nc","notes":null},{"pin_number":"7","function":"Heater","function_code":"h","notes":null},{"pin_number":"8","function":"Cathode and Suppressor Grid (g3)","function_code":"k","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":"0.7","numeric_value":"0.7","unit":"A","param_group":"heater"}],"sections":[{"section_number":1,"section_label":"Pentode","tube_type_key":"power_pentode","specs":[{"key":"Va_max","display_name":"Anode Voltage (max)","value":"375","numeric_value":"375","unit":"V","param_group":"absolute_max"},{"key":"Vs_max","display_name":"Screen Voltage (max)","value":"285","numeric_value":"285","unit":"V","param_group":"absolute_max"},{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"10.5","numeric_value":"10.5","unit":"W","param_group":"absolute_max"},{"key":"Ps_max","display_name":"Screen Dissipation (max)","value":"3.5","numeric_value":"3.5","unit":"W","param_group":"absolute_max"},{"key":"Ik_max","display_name":"Cathode Current (max)","value":"45","numeric_value":"45","unit":"mA","param_group":"absolute_max"},{"key":"Vhk_max","display_name":"Heater-to-Cathode Voltage (max)","value":"200","numeric_value":"200","unit":"V","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":"250","numeric_value":"250","unit":"V","param_group":"typical_operating"},{"key":"Vs","display_name":"Screen Voltage (typical)","value":"250","numeric_value":"250","unit":"V","param_group":"typical_operating"},{"key":"Vg","display_name":"Grid 1 Bias Voltage","value":"-16.5","numeric_value":"-16.5","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"34","numeric_value":"34","unit":"mA","param_group":"typical_operating"},{"key":"mAs","display_name":"Screen Current","value":"7","numeric_value":"7","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"100000","numeric_value":"100000","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"2.5","numeric_value":"2.5","unit":"mA/V","param_group":"typical_operating"},{"key":"Pout","display_name":"Output Power","value":"3.2","numeric_value":"3.2","unit":"W","param_group":"output"},{"key":"rl","display_name":"Load Impedance","value":"7000","numeric_value":"7000","unit":"Ω","param_group":"output"},{"key":"Cgp","display_name":"Grid-to-Plate Capacitance","value":"0.7","numeric_value":"0.7","unit":"pF","param_group":"capacitances"},{"key":"Cin","display_name":"Input Capacitance","value":"7","numeric_value":"7","unit":"pF","param_group":"capacitances"},{"key":"Cout","display_name":"Output Capacitance","value":"11","numeric_value":"11","unit":"pF","param_group":"capacitances"}]},{"section_number":2,"section_label":"Triode Strapped","tube_type_key":"power_triode","specs":[{"key":"Va_max","display_name":"Anode Voltage (max)","value":"375","numeric_value":"375","unit":"V","param_group":"absolute_max"},{"key":"Va","display_name":"Anode Voltage (typical)","value":"250","numeric_value":"250","unit":"V","param_group":"typical_operating"},{"key":"Vg","display_name":"Grid 1 Bias 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