{"type_number":"EL44","canonical_url":"https://tubeofile.com/tubes/EL44","manufacturer":"Philips","tube_type_key":"power_pentode","tube_type_display_name":"Power Pentode","base_name":"Rimlock","description":"Output pentode with Rimlock (B8A) base and top-cap anode connection; indirectly heated. Philips design from 1948 with 0.72 A heater current. Relatively rare type, used in a small number of European radio receivers.","is_directly_heated":false,"completeness":"medium","notes":["Rimlock B8A base with top-cap anode connection — unusual combination for Rimlock tubes.","Heater current of 0.72 A is identical to the EL84, suggesting this was a transitional design between the Rimlock and Noval eras.","Very rare tube — found in very few radio models. The Rimlock-with-top-cap configuration was quickly superseded by the fully-pinned Noval designs.","Referenced in RTT (Radio Technique Telefunken) 2nd edition, 1950."],"references":["https://tdsl.duncanamps.com/show.php?des=EL44","https://www.radiomuseum.org/tubes/?tube=EL44"],"source_urls":{"r_type":null,"tdsl":"https://tdsl.duncanamps.com/show.php?des=EL44","radiomuseum":"https://www.radiomuseum.org/tubes/tube_el44.html"},"raw_equivalents":[],"equivalents":[],"similar":[{"type_number":"EL41","reason":"Same Rimlock B8A base but without top cap — different anode connection method, different ratings","has_detail_page":true},{"type_number":"EL84","reason":"Noval successor to the Rimlock EL4x family — different base, improved design","has_detail_page":true}],"pins":[{"pin_number":"1","function":"Screen Grid (g2)","function_code":"g2","notes":null},{"pin_number":"2","function":"Heater","function_code":"h","notes":null},{"pin_number":"3","function":"Cathode","function_code":"k","notes":null},{"pin_number":"4","function":"Suppressor Grid (g3)","function_code":"g3","notes":null},{"pin_number":"5","function":"Control Grid (g1)","function_code":"g1","notes":null},{"pin_number":"6","function":"No Connection","function_code":"nc","notes":null},{"pin_number":"7","function":"Heater","function_code":"h","notes":null},{"pin_number":"8","function":"Metallization / Shield","function_code":"ia","notes":null},{"pin_number":"TC","function":"Anode (top cap)","function_code":"a","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":"0.72","numeric_value":"0.72","unit":"A","param_group":"heater"}],"sections":[{"section_number":1,"section_label":"Pentode","tube_type_key":"power_pentode","specs":[{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"12","numeric_value":"12","unit":"W","param_group":"absolute_max"},{"key":"Vs","display_name":"Screen Voltage (typical)","value":"80","numeric_value":"80","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"2","numeric_value":"2","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"100000","numeric_value":"100000","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"2.5","numeric_value":"2.5","unit":"mA/V","param_group":"typical_operating"}]}],"synced_at":"2026-04-07T12:45:20.491Z"}