{"type_number":"17AX4","canonical_url":"https://tubeofile.com/tubes/17AX4","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 use as a damper in the horizontal-deflection circuit of television receivers. 16.8V series-string heater version. Designed to withstand high pulse voltages between plate and cathode, particularly useful in autotransformer deflection systems. Except for heater characteristics, identical to the 6AX4GTB and 12AX4GTB.","is_directly_heated":false,"completeness":"high","notes":["Tung-Sol tentative data, August 1, 1960, Plate #5959. Intermediate-shell 5-pin Octal base, glass T-9 bulb, basing 4C6.","Coated unipotential cathode. Any mounting position.","Interelectrode capacitances (approx., without external shield): cathode-to-plate-and-heater 8.5 pF, plate-to-cathode-and-heater 5.0 pF, heater-to-cathode 4.0 pF.","Peak heater-cathode voltage: heater positive — 100V DC, 300V total DC and peak; heater negative — 900V DC, 5000V total DC and peak.","Heater warm-up time approximately 11.0 seconds.","Tube voltage drop at Ib=250 mA DC: 32V.","Operation as a power rectifier is not recommended."],"references":["https://frank.pocnet.net/sheets/127/1/17AX4GTA.pdf"],"source_urls":{"r_type":null,"tdsl":"https://tdsl.duncanamps.com/show.php?des=17AX4","radiomuseum":"https://www.radiomuseum.org/tubes/tube_17AX4.html"},"raw_equivalents":["17AX4GT","17AX4GTA"],"equivalents":[],"similar":[{"type_number":"12AX4GTA","reason":"Same damper diode family but 12.6V heater — not a drop-in due to different heater voltage","has_detail_page":false},{"type_number":"25AX4","reason":"Same damper diode family but 25V heater — not a drop-in due to different heater voltage","has_detail_page":true},{"type_number":"6AX4","reason":"Identical function and pinout but 6.3V heater — not a drop-in due to different heater voltage","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":"16.8","numeric_value":"16.8","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":"Damper Diode","tube_type_key":"rectifier","specs":[{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"5.3","numeric_value":"5.3","unit":"W","param_group":"absolute_max"},{"key":"Vhk_max","display_name":"Heater-to-Cathode Voltage (max)","value":"5000","numeric_value":"5000","unit":"V","param_group":"absolute_max"},{"key":"PIV","display_name":"Peak Inverse Voltage","value":"4400","numeric_value":"4400","unit":"V","param_group":"rectifier"},{"key":"Vdrop","display_name":"Voltage Drop (typical)","value":"32","numeric_value":"32","unit":"V","param_group":"rectifier"},{"key":"Idc_max","display_name":"Max DC Output Current (total, not per-anode)","value":"165","numeric_value":"165","unit":"mA","param_group":"rectifier"},{"key":"Ia_peak","display_name":"Peak Anode Current (surge)","value":"1000","numeric_value":"1000","unit":"mA","param_group":"rectifier"}]}],"synced_at":"2026-04-08T07:49:30.803Z"}