{"type_number":"6BK7","canonical_url":"https://tubeofile.com/tubes/6BK7","manufacturer":"RCA","tube_type_key":"small_signal_triode","tube_type_display_name":"Small Signal Triode","base_name":"Noval","description":"Medium-mu twin triode designed for high-frequency amplifier service. Features unipotential cathodes and a 9-pin miniature base. Each section has mu=43, gm=9300 µmhos, and ra=4600 ohms.","is_directly_heated":false,"completeness":"high","notes":["RCA datasheet (2-57) for the 6BK7-A revision. The 6BK7 and 6BK7A are electrically identical; the A suffix indicates a change in manufacturing process.","GE Essential Characteristics lists classification as 'High-Frequency Twin Triode' with base 9AJ, Rp=4700 ohms, Gm=8500 µmhos at Va=150 V. RCA datasheet gives Rp=4600 ohms, Gm=9300 µmhos — use RCA datasheet values.","Maximum plate voltage is 300 V. Maximum plate dissipation per unit is 2.7 W.","Peak heater-cathode voltage: 200 V max (both negative and positive). Under cutoff conditions in cascode circuits with direct-coupled drive, this may be as high as 300 V (DC component must not exceed 100 V).","Basing designation for bottom view is 9AJ (JETEC)."],"references":["https://frank.pocnet.net/sheets/137/6/6BK7.pdf","https://frank.pocnet.net/sheets/049/6/6BK7A.pdf"],"source_urls":{"r_type":null,"tdsl":"https://tdsl.duncanamps.com/show.php?des=6BK7","radiomuseum":"https://www.radiomuseum.org/tubes/tube_6bk7a.html"},"raw_equivalents":["6BK7A","6BK7B"],"equivalents":[],"similar":[{"type_number":"4BZ8","reason":"Brans Vademecum cross-lists as equivalent — verify pinout and characteristics before substituting","has_detail_page":true},{"type_number":"6BC8","reason":"Similar HF twin triode for cascode circuits — different characteristics","has_detail_page":false},{"type_number":"6BQ7","reason":"Similar HF twin triode with same Noval base but different characteristics — not a drop-in","has_detail_page":false}],"pins":[{"pin_number":"1","function":"Plate (Unit 2)","function_code":"a2","notes":null},{"pin_number":"2","function":"Grid (Unit 2)","function_code":"g1_2","notes":null},{"pin_number":"3","function":"Cathode (Unit 2)","function_code":"k2","notes":null},{"pin_number":"4","function":"Heater","function_code":"h","notes":null},{"pin_number":"5","function":"Heater","function_code":"h","notes":null},{"pin_number":"6","function":"Plate (Unit 1)","function_code":"a1","notes":null},{"pin_number":"7","function":"Grid (Unit 1)","function_code":"g1_1","notes":null},{"pin_number":"8","function":"Cathode (Unit 1)","function_code":"k1","notes":null},{"pin_number":"9","function":"Internal Shield","function_code":"is","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":"0.45","numeric_value":"0.45","unit":"A","param_group":"heater"}],"sections":[{"section_number":1,"section_label":"Triode (each section)","tube_type_key":"small_signal_triode","specs":[{"key":"Va_max","display_name":"Anode Voltage (max)","value":"300","numeric_value":"300","unit":"V","param_group":"absolute_max"},{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"2.7","numeric_value":"2.7","unit":"W","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":"Va","display_name":"Anode Voltage (typical)","value":"150","numeric_value":"150","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"18","numeric_value":"18","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"4600","numeric_value":"4600","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"9.3","numeric_value":"9.3","unit":"mA/V","param_group":"typical_operating"},{"key":"mu","display_name":"Amplification Factor (μ)","value":"43","numeric_value":"43","unit":"—","param_group":"typical_operating"},{"key":"Rk","display_name":"Cathode Resistor (self-bias)","value":"56","numeric_value":"56","unit":"Ω","param_group":"typical_operating"},{"key":"Cgp","display_name":"Grid-to-Plate Capacitance","value":"1.8","numeric_value":"1.8","unit":"pF","param_group":"capacitances"},{"key":"Cgk","display_name":"Grid-to-Cathode Capacitance","value":"3","numeric_value":"3","unit":"pF","param_group":"capacitances"},{"key":"Cin","display_name":"Input Capacitance","value":"1","numeric_value":"1","unit":"pF","param_group":"capacitances"},{"key":"Cout","display_name":"Output Capacitance","value":"2.8","numeric_value":"2.8","unit":"pF","param_group":"capacitances"}]}],"synced_at":"2026-04-07T12:18:27.569Z"}