{"type_number":"217C","canonical_url":"https://tubeofile.com/tubes/217C","manufacturer":"General Electric","tube_type_key":"rectifier","tube_type_display_name":"Rectifier","base_name":"Jumbo4","description":"Half-wave high-vacuum rectifier with directly heated filament cathode. An uprated version of the UV217 with higher ratings. Uses a Jumbo 4-pin bayonet base with top cap anode connection. Designed for high-voltage power supply applications in transmitter and industrial equipment. Type number assigned by RCA in 1926.","is_directly_heated":true,"completeness":"medium","notes":["Directly heated filament cathode — observe warm-up time before applying plate voltage.","Top contact (cap) is the anode connection; the Jumbo 4-pin bayonet base carries filament pins only.","Peak inverse voltage 7500 V makes this suitable for high-voltage transmitter power supplies.","Maximum DC output current is 150 mA with a peak plate current capability of 600 mA."],"references":["https://frank.yueksel.org/sheets/217/2/217C.pdf"],"source_urls":{"r_type":null,"tdsl":"https://tdsl.duncanamps.com/show.php?des=217C","radiomuseum":"https://www.radiomuseum.org/tubes/tube_217c.html"},"raw_equivalents":["UV217C","38117"],"equivalents":[],"similar":[{"type_number":"3B24W","reason":"Related half-wave rectifier listed alongside 217C datasheets on TDSL — different ratings","has_detail_page":false},{"type_number":"CG-2936A","reason":"Normally replaceable, slightly different ratings per radiomuseum","has_detail_page":false}],"pins":[{"pin_number":"1","function":"Filament","function_code":"h","notes":null},{"pin_number":"2","function":"No Connection","function_code":"nc","notes":null},{"pin_number":"3","function":"Filament","function_code":"h","notes":null},{"pin_number":"4","function":"No Connection","function_code":"nc","notes":null},{"pin_number":"TC","function":"Anode (Top Cap)","function_code":"a","notes":null}],"specs":[{"key":"Vh","display_name":"Heater Voltage","value":"10","numeric_value":"10","unit":"V","param_group":"heater"},{"key":"Ah","display_name":"Heater Current","value":"3.25","numeric_value":"3.25","unit":"A","param_group":"heater"}],"sections":[{"section_number":1,"section_label":"Rectifier","tube_type_key":"rectifier","specs":[{"key":"PIV","display_name":"Peak Inverse Voltage","value":"7500","numeric_value":"7500","unit":"V","param_group":"rectifier"},{"key":"Ia_peak","display_name":"Peak Anode Current (surge)","value":"600","numeric_value":"600","unit":"mA","param_group":"rectifier"},{"key":"Idc_max","display_name":"Max DC Output Current (total, not per-anode)","value":"150","numeric_value":"150","unit":"mA","param_group":"rectifier"}]}],"synced_at":"2026-04-08T07:49:50.878Z"}