{"type_number":"19AU4","canonical_url":"https://tubeofile.com/tubes/19AU4","manufacturer":"Tung-Sol","tube_type_key":"rectifier","tube_type_display_name":"Rectifier","base_name":"Octal","description":"Half-wave vacuum rectifier (heater-cathode type diode) designed for television horizontal-frequency damper service. 18.9V series-string heater version. Designed to withstand high voltage pulses between cathode and both heater and plate elements in direct-drive circuits. Except for higher DC output current and peak plate current of the 19AU4GTA, the two tubes are identical.","is_directly_heated":false,"completeness":"high","notes":["Tung-Sol tentative data, December 1, 1956, Plate #4843. Short intermediate-shell 5 or 6 pin Octal, glass T-9 bulb, basing 4CG.","Coated unipotential cathode. Any mounting position.","Socket terminals #1, #2, #4 and #6 should not be used as tie points. Pin #1 omitted on 5-pin base.","Interelectrode capacitances (without external shield): heater-to-cathode (H to K) 4.0 pF, plate-to-cathode-and-heater (P to H+K) 8.5 pF, cathode-to-plate-and-heater (K to P+H) 11.5 pF.","Peak heater-cathode voltage: heater positive — 100V DC, 300V total DC and peak; heater negative — 900V DC, 4500V total DC and peak (absolute maximum).","Heater warm-up time approximately 11.0 seconds.","Average tube voltage drop at 350 mA (with tube conducting 350 mA): 25V.","Values for 19AU4GTA: DC output current max 190 mA, steady-state peak plate current 1150 mA. Values for 19AU4: DC output current max 175 mA, steady-state peak plate current 1050 mA."],"references":["https://frank.pocnet.net/sheets/127/1/19AU4.pdf"],"source_urls":{"r_type":null,"tdsl":"https://tdsl.duncanamps.com/show.php?des=19AU4","radiomuseum":"https://www.radiomuseum.org/tubes/tube_19AU4.html"},"raw_equivalents":["19AU4GTA"],"equivalents":[],"similar":[{"type_number":"6AU4","reason":"Same damper diode family but 6.3V heater — not a drop-in due to different heater voltage","has_detail_page":true},{"type_number":"6AX4","reason":"Half-wave Octal TV damper rectifier with 6.3V heater — different heater voltage and slightly different ratings","has_detail_page":true}],"pins":[{"pin_number":"2","function":"Internal Connection — Do Not Use","function_code":"ic","notes":null},{"pin_number":"3","function":"Cathode","function_code":"k","notes":null},{"pin_number":"5","function":"Plate (Anode)","function_code":"a","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":"18.9","numeric_value":"18.9","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":"Damper Diode","tube_type_key":"rectifier","specs":[{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"6.0","numeric_value":"6","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":"25","numeric_value":"25","unit":"V","param_group":"rectifier"},{"key":"Idc_max","display_name":"Max DC Output Current (total, not per-anode)","value":"175","numeric_value":"175","unit":"mA","param_group":"rectifier"},{"key":"Ia_peak","display_name":"Peak Anode Current (surge)","value":"1050","numeric_value":"1050","unit":"mA","param_group":"rectifier"}]}],"synced_at":"2026-04-08T07:49:35.496Z"}