{"type_number":"6AF4","canonical_url":"https://tubeofile.com/tubes/6AF4","manufacturer":"Tung-Sol","tube_type_key":"small_signal_triode","tube_type_display_name":"Small Signal Triode","base_name":"B7G","description":"UHF triode oscillator designed for television tuner local oscillator service at frequencies from 470 to 890 MHz. Miniature B7G base with 6.3V indirectly heated cathode. Widely used in early UHF television converters and tuners.","is_directly_heated":false,"completeness":"medium","notes":["GE Essential Characteristics classifies as UHF Triode Oscillator: Va=80V, Ia=13.5mA, gm=6500 umhos, Rp=2100 ohms, Pa_max=2.5W, Va_max=150V.","Designed specifically for UHF TV tuner local oscillator use in the 470-890 MHz range.","Sams Substitution Handbook lists 6AF4A, 6AN4, EC94, ECLL800 as substitutes.","Muiderkring Handbook page 136 lists this type."],"references":["https://frank.pocnet.net/sheets/093/6/6AF4.pdf"],"source_urls":{"r_type":null,"tdsl":null,"radiomuseum":"https://www.radiomuseum.org/tubes/tube_6af4.html"},"raw_equivalents":["6AF4A","EC94"],"equivalents":[],"similar":[{"type_number":"2AF4","reason":"Same UHF triode with 2.34V heater — not interchangeable without heater change","has_detail_page":false},{"type_number":"3AF4","reason":"Same UHF triode with 3.15V heater — not interchangeable without heater change","has_detail_page":false},{"type_number":"6AN4","reason":"Similar UHF triode oscillator on B7G base — Sams lists as substitute","has_detail_page":false}],"pins":[{"pin_number":"1","function":"Grid","function_code":"g1","notes":null},{"pin_number":"2","function":"Cathode","function_code":"k","notes":null},{"pin_number":"3","function":"Heater","function_code":"h","notes":null},{"pin_number":"4","function":"Heater","function_code":"h","notes":null},{"pin_number":"5","function":"Plate","function_code":"a","notes":null},{"pin_number":"6","function":"No Connection","function_code":"nc","notes":null},{"pin_number":"7","function":"Cathode","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":"0.225","numeric_value":"0.225","unit":"A","param_group":"heater"}],"sections":[{"section_number":1,"section_label":"Triode","tube_type_key":"small_signal_triode","specs":[{"key":"Va_max","display_name":"Anode Voltage (max)","value":"150","numeric_value":"150","unit":"V","param_group":"absolute_max"},{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"2.5","numeric_value":"2.5","unit":"W","param_group":"absolute_max"},{"key":"Va","display_name":"Anode Voltage (typical)","value":"80","numeric_value":"80","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"13.5","numeric_value":"13.5","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"2100","numeric_value":"2100","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"6.5","numeric_value":"6.5","unit":"mA/V","param_group":"typical_operating"}]}],"synced_at":"2026-04-07T12:15:03.001Z"}