{"type_number":"6X4","canonical_url":"https://tubeofile.com/tubes/6X4","manufacturer":null,"tube_type_key":"rectifier","tube_type_display_name":"Rectifier","base_name":"B7G","description":"Miniature heater-cathode type twin diode designed for full-wave rectifier operation in compact power supplies. Intended for service in automobile and AC radio receivers.","is_directly_heated":false,"completeness":"high","notes":["Indirectly heated (coated unipotential cathode) — no warm-up delay concerns for B+ application, unlike directly heated rectifiers.","Maximum ratings differ by filter type: with capacitor-input filter, max AC plate-supply voltage per plate is 325 V RMS at 70 mA; with choke-input filter, max is 450 V RMS at 70 mA. See Rating Chart I in the datasheet.","When capacitor-input filter is used, a minimum total plate-supply resistance of 525 ohms per plate is required to limit peak currents.","Heater-cathode voltage limits are asymmetric: +100 V DC / +200 V peak (heater positive), -450 V peak (heater negative). This matters for elevated heater supplies.","12X4 is electrically identical but with 12.6 V heater — developed for vibrator power supplies in car radios.","6063 is a different-rating substitute, not a direct equivalent.","Tube voltage drop is approximately 22 V at full rated current of 70 mA DC — higher than larger rectifiers like GZ34 (~15 V) but typical for miniature types.","Brans Vademecum groups 6X4 with the 6X5/EZ90 family across multiple base types.","Philips interchange guide lists EZ90 as direct replacement (CV493)."],"references":["https://frank.pocnet.net/sheets/049/6/6X4.pdf","https://w140.com/tekwiki/images/7/7b/GE_6X4_data_sheet.pdf"],"source_urls":{"r_type":"https://www.r-type.org/exhib/aaa0233.htm","tdsl":"https://tdsl.duncanamps.com/show.php?des=6X4","radiomuseum":"https://www.radiomuseum.org/tubes/tube_6x4.html"},"raw_equivalents":["EZ90","CV493","CV8203","CV8223","CV8237","U78","U707","V2M70","6063","6X4W","6X4WA","E90Z","EZ85","GB6X4WA","6C4P","6202"],"equivalents":[{"type_number":"6202","equivalence_type":"direct","notes":null},{"type_number":"6C4P","equivalence_type":"direct","notes":null}],"similar":[{"type_number":"12X4","reason":"Electrically identical but 12.6V heater — not a drop-in in 6.3V circuits","has_detail_page":true},{"type_number":"6X5GT","reason":"Same function (full-wave rectifier, 6.3V heater, 70mA) but Octal base — not pin-compatible with B7G","has_detail_page":false}],"pins":[{"pin_number":"1","function":"Plate 2 (Anode 2)","function_code":"a2","notes":null},{"pin_number":"2","function":"No Connection","function_code":"nc","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":"No Connection","function_code":"nc","notes":null},{"pin_number":"6","function":"Plate 1 (Anode 1)","function_code":"a1","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":"0.6","numeric_value":"0.6","unit":"A","param_group":"heater"}],"sections":[{"section_number":1,"section_label":"Rectifier","tube_type_key":"rectifier","specs":[{"key":"Va_max","display_name":"Anode Voltage (max)","value":"450","numeric_value":"450","unit":"V","param_group":"absolute_max"},{"key":"Vhk_max","display_name":"Heater-to-Cathode Voltage (max)","value":"450","numeric_value":"450","unit":"V","param_group":"absolute_max"},{"key":"PIV","display_name":"Peak Inverse Voltage","value":"1250","numeric_value":"1250","unit":"V","param_group":"rectifier"},{"key":"Vdrop","display_name":"Voltage Drop (typical)","value":"22","numeric_value":"22","unit":"V","param_group":"rectifier"},{"key":"C_max","display_name":"Max C-input Filter Capacitor","value":"40","numeric_value":"40","unit":"µF","param_group":"rectifier"},{"key":"Ia_peak","display_name":"Peak Anode Current (surge)","value":"245","numeric_value":"245","unit":"mA","param_group":"rectifier"},{"key":"Idc_max","display_name":"Max DC Output Current (total, not per-anode)","value":"70","numeric_value":"70","unit":"mA","param_group":"rectifier"},{"key":"Rs_min","display_name":"Min Series Resistance (C-input)","value":"525","numeric_value":"525","unit":"Ω","param_group":"rectifier"}]}],"synced_at":"2026-04-09T05:17:20.408Z"}