{"type_number":"6FR7","canonical_url":"https://tubeofile.com/tubes/6FR7","manufacturer":null,"tube_type_key":"small_signal_triode","tube_type_display_name":"Small Signal Triode","base_name":"Noval","description":"Medium-mu dual triode in Noval envelope. A variant of the 6CG7/6FQ7 family with controlled heater warm-up time. Electrically identical to 6CG7 and 6FQ7. Two identical triode sections with individual cathodes.","is_directly_heated":false,"completeness":"high","notes":["The 6FR7 is electrically identical to the 6CG7 and 6FQ7, with the addition of controlled heater warm-up time for use in series-string heater circuits.","Valve equivalents reference lists this as a double triode on B9A (Noval) base with 6.3V heater."],"references":["https://frank.pocnet.net/sheets/127/6/6CG7.pdf","https://tdsl.duncanamps.com/show.php?des=6FR7"],"source_urls":{"r_type":null,"tdsl":"https://tdsl.duncanamps.com/show.php?des=6FR7","radiomuseum":"https://www.radiomuseum.org/tubes/tube_6fr7.html"},"raw_equivalents":["6CG7","6FQ7"],"equivalents":[{"type_number":"6CG7","equivalence_type":"direct","notes":null}],"similar":[{"type_number":"6SN7","reason":"Same electricals (mu=20, Rp=7700, gm=2600) but Octal base — requires socket adapter","has_detail_page":true},{"type_number":"8CG7","reason":"Same electricals but 8.4V heater — not directly interchangeable","has_detail_page":true},{"type_number":"8FQ7","reason":"Same electricals but 8.4V heater — not directly interchangeable","has_detail_page":true}],"pins":[{"pin_number":"1","function":"Anode (section 2)","function_code":"a2","notes":null},{"pin_number":"2","function":"Grid (section 2)","function_code":"g1_2","notes":null},{"pin_number":"3","function":"Cathode (section 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":"Anode (section 1)","function_code":"a1","notes":null},{"pin_number":"7","function":"Grid (section 1)","function_code":"g1_1","notes":null},{"pin_number":"8","function":"Cathode (section 1)","function_code":"k1","notes":null},{"pin_number":"9","function":"Internal shield","function_code":"ic","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":"0.6","numeric_value":"0.6","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":"2.8","numeric_value":"2.8","unit":"W","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 Voltage","value":"-8","numeric_value":"-8","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"9","numeric_value":"9","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"7700","numeric_value":"7700","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"2.6","numeric_value":"2.6","unit":"mA/V","param_group":"typical_operating"},{"key":"mu","display_name":"Amplification Factor (μ)","value":"20","numeric_value":"20","unit":"—","param_group":"typical_operating"}]}],"synced_at":"2026-04-07T12:23:52.817Z"}