{"type_number":"EL32","canonical_url":"https://tubeofile.com/tubes/EL32","manufacturer":"Mullard","tube_type_key":"power_pentode","tube_type_display_name":"Power Pentode","base_name":"Octal","description":"Output pentode with 200mA heater for use in A.C., D.C./A.C. or car radio receivers","is_directly_heated":false,"completeness":"high","notes":["Control grid (g1) is connected via a top cap, not a base pin. Requires a top-cap clip connector.","Suppressor grid (g3) is internally connected to the cathode.","The VT52 designation (RAF) refers to this tube and is NOT the same as the American VT-52 (type 45 power triode). Take care to avoid confusion.","Designed for low-power output stages in AC/DC and car radio receivers. The 200mA heater current allows series-string heater operation.","Maximum grid resistor is only 100 kOhm for self-bias and 600 kOhm for fixed-bias operation — unusually restrictive for a pentode.","Widely used in WWII British military radio equipment including the T1143 transmitter, TR1196 transceiver, and B2 spy set (clandestine radio)."],"references":["https://frank.pocnet.net/sheets/154/e/EL32.pdf","https://www.r-type.org/exhib/aaa1118.htm"],"source_urls":{"r_type":"https://www.r-type.org/exhib/aaa1118.htm","tdsl":"https://tdsl.duncanamps.com/show.php?des=EL32","radiomuseum":"https://www.radiomuseum.org/tubes/tube_el32.html"},"raw_equivalents":["CV1052","CV996","1637","VT52","OM9"],"equivalents":[{"type_number":"VT-52","equivalence_type":"direct","notes":null}],"similar":[{"type_number":"EL2","reason":"Electrically identical predecessor but uses a different base (side-contact B8B), not pin-compatible","has_detail_page":true}],"pins":[{"pin_number":"1","function":"No Connection","function_code":"nc","notes":null},{"pin_number":"2","function":"Heater","function_code":"h","notes":null},{"pin_number":"3","function":"Anode","function_code":"a","notes":null},{"pin_number":"4","function":"Screen Grid","function_code":"g2","notes":null},{"pin_number":"5","function":"No Connection","function_code":"nc","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":"Cathode","function_code":"k","notes":null},{"pin_number":"TC","function":"Control Grid","function_code":"g1","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":"0.2","numeric_value":"0.2","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":"250","numeric_value":"250","unit":"V","param_group":"absolute_max"},{"key":"Vs_max","display_name":"Screen Voltage (max)","value":"250","numeric_value":"250","unit":"V","param_group":"absolute_max"},{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"8","numeric_value":"8","unit":"W","param_group":"absolute_max"},{"key":"Ps_max","display_name":"Screen Dissipation (max)","value":"1.6","numeric_value":"1.6","unit":"W","param_group":"absolute_max"},{"key":"Ik_max","display_name":"Cathode Current (max)","value":"45","numeric_value":"45","unit":"mA","param_group":"absolute_max"},{"key":"Vhk_max","display_name":"Heater-to-Cathode Voltage (max)","value":"50","numeric_value":"50","unit":"V","param_group":"absolute_max"},{"key":"Rg_max","display_name":"Max Grid Resistor","value":"0.1","numeric_value":"0.1","unit":"MΩ","param_group":"absolute_max"},{"key":"Va","display_name":"Anode Voltage (typical)","value":"250","numeric_value":"250","unit":"V","param_group":"typical_operating"},{"key":"Vs","display_name":"Screen Voltage (typical)","value":"250","numeric_value":"250","unit":"V","param_group":"typical_operating"},{"key":"Vg","display_name":"Grid 1 Bias Voltage","value":"-18","numeric_value":"-18","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"32","numeric_value":"32","unit":"mA","param_group":"typical_operating"},{"key":"mAs","display_name":"Screen Current","value":"5","numeric_value":"5","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"70000","numeric_value":"70000","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"2.8","numeric_value":"2.8","unit":"mA/V","param_group":"typical_operating"},{"key":"Rk","display_name":"Cathode Resistor (self-bias)","value":"670","numeric_value":"670","unit":"Ω","param_group":"typical_operating"},{"key":"Pout","display_name":"Output Power","value":"3.6","numeric_value":"3.6","unit":"W","param_group":"output"},{"key":"rl","display_name":"Load Impedance","value":"8000","numeric_value":"8000","unit":"Ω","param_group":"output"}]},{"section_number":2,"section_label":"Triode Strapped","tube_type_key":"power_triode","specs":[{"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":"-20","numeric_value":"-20","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"30","numeric_value":"30","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"3100","numeric_value":"3100","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"2.6","numeric_value":"2.6","unit":"mA/V","param_group":"typical_operating"},{"key":"mu","display_name":"Amplification Factor (μ)","value":"8","numeric_value":"8","unit":"—","param_group":"typical_operating"}]}],"synced_at":"2026-04-07T12:44:02.365Z"}