{"type_number":"UL84","canonical_url":"https://tubeofile.com/tubes/UL84","manufacturer":"Philips","tube_type_key":"power_pentode","tube_type_display_name":"Power Pentode","base_name":"Noval","description":"Power pentode in Noval envelope with 45V/100mA heater for series-string (AC/DC) operation. European designation in the Pro-Electron system (U = 100mA series string, L = output pentode). Designed for audio output stages in AC/DC receivers.","is_directly_heated":false,"completeness":"medium","notes":["The UL84 is the 100mA series-string heater version of the EL84/6BQ5 family. The 45V heater is designed for direct operation from series-connected heater strings in AC/DC sets.","Muiderkring category code 'P' = output pentode. The American designation is 45B5.","Pro-Electron naming: U = 100mA series heater, L = output pentode, 84 = type number."],"references":["https://tdsl.duncanamps.com/show.php?des=UL84"],"source_urls":{"r_type":null,"tdsl":"https://tdsl.duncanamps.com/show.php?des=UL84","radiomuseum":"https://www.radiomuseum.org/tubes/tube_ul84.html"},"raw_equivalents":["45B5"],"equivalents":[],"similar":[{"type_number":"EL84","reason":"Same tube electricals but 6.3V parallel heater — requires different heater circuit design","has_detail_page":true},{"type_number":"PL84","reason":"Same tube electricals but 300mA series-string heater — different heater current, not interchangeable","has_detail_page":true},{"type_number":"PL95","reason":"Similar power pentode for series-string but B7G base and different characteristics","has_detail_page":true}],"pins":[{"pin_number":"1","function":"Grid 3 (Suppressor)","function_code":"g3","notes":null},{"pin_number":"2","function":"Grid 1 (Control Grid)","function_code":"g1","notes":null},{"pin_number":"3","function":"Cathode","function_code":"k","notes":null},{"pin_number":"4","function":"Heater","function_code":"h","notes":null},{"pin_number":"5","function":"Heater","function_code":"h","notes":null},{"pin_number":"6","function":"No Connection","function_code":"nc","notes":null},{"pin_number":"7","function":"Anode","function_code":"a","notes":null},{"pin_number":"8","function":"Internal shield","function_code":"shell","notes":null},{"pin_number":"9","function":"Grid 2 (Screen)","function_code":"g2","notes":null}],"specs":[{"key":"Vh","display_name":"Heater Voltage","value":"45","numeric_value":"45","unit":"V","param_group":"heater"},{"key":"Ah","display_name":"Heater Current","value":"0.1","numeric_value":"0.1","unit":"A","param_group":"heater"}],"sections":[{"section_number":1,"section_label":"Pentode","tube_type_key":"power_pentode","specs":[{"key":"Va_max","display_name":"Anode Voltage (max)","value":"300","numeric_value":"300","unit":"V","param_group":"absolute_max"},{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"12","numeric_value":"12","unit":"W","param_group":"absolute_max"},{"key":"Vg2_max","display_name":"Screen Voltage (max)","value":"300","numeric_value":"300","unit":"V","param_group":"absolute_max"},{"key":"Va","display_name":"Anode Voltage (typical)","value":"250","numeric_value":"250","unit":"V","param_group":"typical_operating"},{"key":"Vg","display_name":"Grid 1 Bias Voltage","value":"-7.3","numeric_value":"-7.3","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"48","numeric_value":"48","unit":"mA","param_group":"typical_operating"},{"key":"Vg2","display_name":"Screen Voltage","value":"250","numeric_value":"250","unit":"V","param_group":"typical_operating"},{"key":"mAg2","display_name":"Screen Current","value":"5.5","numeric_value":"5.5","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"38000","numeric_value":"38000","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"11.3","numeric_value":"11.3","unit":"mA/V","param_group":"typical_operating"},{"key":"Po","display_name":"Output Power","value":"5.7","numeric_value":"5.7","unit":"W","param_group":"output_stage"}]}],"synced_at":"2026-04-07T12:52:40.609Z"}