{"type_number":"6AU4","canonical_url":"https://tubeofile.com/tubes/6AU4","manufacturer":"RCA","tube_type_key":"rectifier","tube_type_display_name":"Rectifier","base_name":"Octal","description":"Half-wave vacuum rectifier with indirectly-heated coated unipotential cathode, designed for television damper service. Octal base (basing 4CG). RCA design.","is_directly_heated":false,"completeness":"high","notes":["Pin 2 is an internal connection — do not use as a tie point.","Socket terminals 1, 2, 4, and 6 should not be used as tie points.","On the 5-pin base, pin 1 as well as pins 4 and 6 is omitted.","Peak inverse plate voltage rating of 4500V applies for operation in a 525-line, 30-frame system.","DC component of plate voltage must not exceed 900V.","DC component of heater-cathode voltage must not exceed 100V.","6AU4GT and 6AU4GTA are envelope/rating variants — pin-compatible drop-in replacements.","Tube voltage drop (Vdrop) is not stated as a discrete figure in the RCA 6AU4-GTA datasheet. Derived from the Average Plate Characteristic curve (92CS-8651R1, Ef=6.3V) at the maximum DC plate current of 210 mA, where plate voltage reads approximately 20 V."],"references":["https://frank.pocnet.net/sheets/049/6/6AU4GTA.pdf"],"source_urls":{"r_type":null,"tdsl":"https://tdsl.duncanamps.com/show.php?des=6AU4","radiomuseum":"https://www.radiomuseum.org/tubes/tube_6au4gta.html"},"raw_equivalents":["6AU4GT","6AU4GTA"],"equivalents":[],"similar":[{"type_number":"12D4","reason":"Same half-wave TV damper family but 12.6V heater — not interchangeable without heater string redesign","has_detail_page":true},{"type_number":"6AX4GTB","reason":"Half-wave Octal TV damper rectifier — lower PIV (4400V vs 4500V), lower peak plate current","has_detail_page":false}],"pins":[{"pin_number":"1","function":"Internal Connection (Shell)","function_code":"ia","notes":null},{"pin_number":"2","function":"Internal Connection","function_code":"ic","notes":null},{"pin_number":"3","function":"Cathode","function_code":"k","notes":null},{"pin_number":"4","function":"No Connection","function_code":"nc","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":"Heater","function_code":"h","notes":null},{"pin_number":"8","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":"1.8","numeric_value":"1.8","unit":"A","param_group":"heater"}],"sections":[{"section_number":1,"section_label":"Rectifier","tube_type_key":"rectifier","specs":[{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"6.5","numeric_value":"6.5","unit":"W","param_group":"absolute_max"},{"key":"Vhk_max","display_name":"Heater-to-Cathode Voltage (max)","value":"4500","numeric_value":"4500","unit":"V","param_group":"absolute_max"},{"key":"PIV","display_name":"Peak Inverse Voltage","value":"4500","numeric_value":"4500","unit":"V","param_group":"rectifier"},{"key":"Vdrop","display_name":"Voltage Drop (typical)","value":"20","numeric_value":"20","unit":"V","param_group":"rectifier"},{"key":"Idc_max","display_name":"Max DC Output Current (total, not per-anode)","value":"210","numeric_value":"210","unit":"mA","param_group":"rectifier"},{"key":"Ia_peak","display_name":"Peak Anode Current (surge)","value":"1300","numeric_value":"1300","unit":"mA","param_group":"rectifier"}]}],"synced_at":"2026-04-09T05:17:02.602Z"}