{"type_number":"GZ30","canonical_url":"https://tubeofile.com/tubes/GZ30","manufacturer":null,"tube_type_key":"rectifier","tube_type_display_name":"Rectifier","base_name":"Octal","description":"Full-wave vacuum rectifier for larger domestic equipment and audio amplifiers. Indirectly heated (cathode sleeve) with octal base. Designed for use with center-tapped transformer in full-wave configuration, delivering up to 125 mA DC output.","is_directly_heated":false,"completeness":"high","notes":["Indirectly heated (cathode sleeve) — provides slow ramp-up of B+ voltage, reducing cathode stripping in signal and output tubes compared to directly heated rectifiers like 5U4G.","Pin 1 is an internal metallisation/shield connection, not a no-connection pin. It should be grounded for proper shielding.","CV1864 is listed by TDSL as a different-rating substitute — verify ratings before substituting.","Voltage drop data (20 V) sourced from tubemaze.info measurement comparison (https://tubemaze.info/sound-of-rectifier/), not from the manufacturer datasheet."],"references":["https://frank.pocnet.net/sheets/129/g/GZ30.pdf","http://www.r-type.org/exhib/aad0218.htm","https://tubemaze.info/sound-of-rectifier/"],"source_urls":{"r_type":"http://www.r-type.org/exhib/aad0218.htm","tdsl":"https://tdsl.duncanamps.com/show.php?des=GZ30","radiomuseum":"https://www.radiomuseum.org/tubes/tube_gz30.html"},"raw_equivalents":["5Z4G","5Z4GT","5Z4","CV1863","CV2748","5AQ4","R52","VT74","CV3933","5C4S"],"equivalents":[{"type_number":"5C4S","equivalence_type":"direct","notes":null}],"similar":[{"type_number":"AZ41","reason":"Electrically similar Rimlock rectifier but different base (B8A vs Octal) — not pin-compatible","has_detail_page":true}],"pins":[{"pin_number":"1","function":"Internal Connection (metallisation)","function_code":"ia","notes":null},{"pin_number":"2","function":"Heater","function_code":"h","notes":null},{"pin_number":"3","function":"No Connection","function_code":"nc","notes":null},{"pin_number":"4","function":"Anode 2 (Plate 2)","function_code":"a2","notes":null},{"pin_number":"5","function":"No Connection","function_code":"nc","notes":null},{"pin_number":"6","function":"Anode 1 (Plate 1)","function_code":"a1","notes":null},{"pin_number":"7","function":"No Connection","function_code":"nc","notes":null},{"pin_number":"8","function":"Heater / Cathode","function_code":"k","notes":null}],"specs":[{"key":"Vh","display_name":"Heater Voltage","value":"5.0","numeric_value":"5","unit":"V","param_group":"heater"},{"key":"Ah","display_name":"Heater Current","value":"2.0","numeric_value":"2","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":"350","numeric_value":"350","unit":"V","param_group":"absolute_max"},{"key":"PIV","display_name":"Peak Inverse Voltage","value":"1400","numeric_value":"1400","unit":"V","param_group":"rectifier"},{"key":"Vdrop","display_name":"Voltage Drop (typical)","value":"20","numeric_value":"20","unit":"V","param_group":"rectifier"},{"key":"C_max","display_name":"Max C-input Filter Capacitor","value":"50","numeric_value":"50","unit":"µF","param_group":"rectifier"},{"key":"Idc_max","display_name":"Max DC Output Current (total, not per-anode)","value":"125","numeric_value":"125","unit":"mA","param_group":"rectifier"},{"key":"Rs_min","display_name":"Min Series Resistance (C-input)","value":"380","numeric_value":"380","unit":"Ω","param_group":"rectifier"}]}],"synced_at":"2026-04-08T07:55:57.397Z"}