{"type_number":"S11E12","canonical_url":"https://tubeofile.com/tubes/S11E12","manufacturer":"AEI / Ediswan","tube_type_key":"beam_tetrode","tube_type_display_name":"Beam Tetrode","base_name":"IO","description":"Special Quality Beam Tetrode, indirectly heated, for series or shunt regulator service in stabilised power supplies","is_directly_heated":false,"completeness":"medium","notes":["Beam plates (pin 6) must be connected to cathode (pin 8) at the valve holder.","Designed for series or shunt regulator service in stabilised power supplies, intended for parallel operation of multiple tubes. The typical operating conditions (Va = Vg2 = 150V, Ia = 200 mA) reflect regulator use, not audio amplification.","Heater-to-cathode voltage limit is polarity-dependent: 350V with heater negative relative to cathode, 150V with heater positive. In floating-cathode regulator circuits, ensure the heater is wired negative.","Triode-connected characteristic curves are published in the datasheet (pages 6–7), but gm and ra are not explicitly stated. The similar 12E1 shows triode gm ≈ 9.5 mA/V and ra ≈ 600 Ω at comparable operating points.","Special shock-resistant construction: rated for 2 g continuous acceleration and 500 g short-duration shock, intended for military or airborne applications."],"references":["https://frank.pocnet.net/sheets/025/s/S11E12.pdf","https://tdsl.duncanamps.com/show.php?des=S11E12"],"source_urls":{"r_type":null,"tdsl":"https://tdsl.duncanamps.com/show.php?des=S11E12","radiomuseum":"https://www.radiomuseum.org/tubes/tube_s11e12.html"},"raw_equivalents":["CV4060","VX6114"],"equivalents":[],"similar":[{"type_number":"12E1","reason":"Indirectly heated regulator beam tetrode with near-identical operating characteristics (gm 13.5 vs 14 mA/V, Pa_max 28 vs 35W), but 12E1 has anode on top cap rather than base pin 3 — not pin-compatible without rewiring.","has_detail_page":true}],"pins":[{"pin_number":"1","function":"Internal Connection","function_code":"ic","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":"Control Grid","function_code":"g1","notes":null},{"pin_number":"6","function":"Beam Plates","function_code":"bp","notes":null},{"pin_number":"7","function":"Heater","function_code":"h","notes":null},{"pin_number":"8","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":"1.6","numeric_value":"1.6","unit":"A","param_group":"heater"}],"sections":[{"section_number":1,"section_label":"Beam Tetrode","tube_type_key":"beam_tetrode","specs":[{"key":"Va_max","display_name":"Anode Voltage (max)","value":"800","numeric_value":"800","unit":"V","param_group":"absolute_max"},{"key":"Va_peak_max","display_name":"Peak Anode Voltage (max)","value":"1500","numeric_value":"1500","unit":"V","param_group":"absolute_max"},{"key":"Vs_max","display_name":"Screen Voltage (max)","value":"300","numeric_value":"300","unit":"V","param_group":"absolute_max"},{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"28","numeric_value":"28","unit":"W","param_group":"absolute_max"},{"key":"Ps_max","display_name":"Screen Dissipation (max)","value":"5","numeric_value":"5","unit":"W","param_group":"absolute_max"},{"key":"Ik_max","display_name":"Cathode Current (max)","value":"300","numeric_value":"300","unit":"mA","param_group":"absolute_max"},{"key":"Vhk_max","display_name":"Heater-to-Cathode Voltage (max)","value":"350","numeric_value":"350","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":"150","numeric_value":"150","unit":"V","param_group":"typical_operating"},{"key":"Vs","display_name":"Screen Voltage (typical)","value":"150","numeric_value":"150","unit":"V","param_group":"typical_operating"},{"key":"Vg","display_name":"Grid 1 Bias Voltage","value":"-8.5","numeric_value":"-8.5","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"200","numeric_value":"200","unit":"mA","param_group":"typical_operating"},{"key":"mAs","display_name":"Screen Current","value":"12","numeric_value":"12","unit":"mA","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"13.5","numeric_value":"13.5","unit":"mA/V","param_group":"typical_operating"},{"key":"Cgp","display_name":"Grid-to-Plate Capacitance","value":"1.8","numeric_value":"1.8","unit":"pF","param_group":"capacitances"},{"key":"Cin","display_name":"Input Capacitance","value":"19.5","numeric_value":"19.5","unit":"pF","param_group":"capacitances"},{"key":"Cout","display_name":"Output Capacitance","value":"16.5","numeric_value":"16.5","unit":"pF","param_group":"capacitances"},{"key":null,"display_name":"Maximum Control Grid Voltage","value":"-100","numeric_value":"-100","unit":"V","param_group":null},{"key":null,"display_name":"Inner Amplification Factor (µg1-g2)","value":"5.5","numeric_value":"5.5","unit":null,"param_group":null},{"key":null,"display_name":"Heater-to-Cathode Voltage (max, heater positive)","value":"150","numeric_value":"150","unit":"V","param_group":null},{"key":null,"display_name":"Maximum Grid Resistor (cathode follower)","value":"1","numeric_value":"1","unit":"MΩ","param_group":null},{"key":null,"display_name":"Maximum Voltage between g1 and g2","value":"400","numeric_value":"400","unit":"V","param_group":null}]},{"section_number":2,"section_label":"Triode Strapped","tube_type_key":"power_triode","specs":[{"key":"mu","display_name":"Amplification Factor (μ)","value":"5.5","numeric_value":"5.5","unit":"—","param_group":"typical_operating"}]}],"synced_at":"2026-04-23T00:37:33.627Z"}