{"type_number":"EF95","canonical_url":"https://tubeofile.com/tubes/EF95","manufacturer":"Mullard","tube_type_key":"ss_pentode","tube_type_display_name":"Small Signal Pentode","base_name":"B7G","description":"Low noise, high slope V.H.F. pentode primarily intended for use as an r.f. and i.f. amplifier at frequencies up to 400 MHz.","is_directly_heated":false,"completeness":"high","notes":["Suppressor grid (g3) is internally connected to cathode.","Pin 7 (cathode) and pin 2 (cathode) are connected internally — both must be grounded for proper shielding.","Vs_max from Mullard is 140 V (design centre), while RCA rates the 6AK5 screen at 180 V max. The Mullard 140 V figure is used here as the conservative rating.","Pg2 max depends on screen voltage: 0.5 W for Vg2 up to 90 V (RCA), 500 mW design centre (Mullard).","M8100 and 5654 are special-quality (ruggedised/selected) versions; CV850 is the UK military designation.","Triode connection data is from the Mullard datasheet (page D1). Schlangen measured slightly lower values (μ=30, gm=6.0 mA/V, ra=5.0 kΩ).","Capacitance values listed are for shielded operation (external shield connected to cathode per B7G base)."],"references":["https://frank.pocnet.net/sheets/129/e/EF95.pdf","https://frank.pocnet.net/sheets/049/6/6AK5.pdf"],"source_urls":{"r_type":"https://www.r-type.org/exhib/aaf0008.htm","tdsl":"https://tdsl.duncanamps.com/show.php?des=EF95","radiomuseum":"https://www.radiomuseum.org/tubes/tube_ef95.html"},"raw_equivalents":["6AK5","5654","CV850","M8100","6069","6J1","PM05","6F32","E95F","408A","5743"],"equivalents":[{"type_number":"5743","equivalence_type":"direct","notes":null},{"type_number":"6AK5","equivalence_type":"direct","notes":null}],"similar":[],"pins":[{"pin_number":"1","function":"Control Grid","function_code":"g1","notes":null},{"pin_number":"2","function":"Cathode","function_code":"k","notes":null},{"pin_number":"3","function":"Heater","function_code":"h","notes":null},{"pin_number":"4","function":"Heater","function_code":"h","notes":null},{"pin_number":"5","function":"Anode","function_code":"a","notes":null},{"pin_number":"6","function":"Screen Grid","function_code":"g2","notes":null},{"pin_number":"7","function":"Cathode, Suppressor Grid (g3 internal)","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":"0.175","numeric_value":"0.175","unit":"A","param_group":"heater"}],"sections":[{"section_number":1,"section_label":"Pentode","tube_type_key":"ss_pentode","specs":[{"key":"Va_max","display_name":"Anode Voltage (max)","value":"180","numeric_value":"180","unit":"V","param_group":"absolute_max"},{"key":"Vs_max","display_name":"Screen Voltage (max)","value":"140","numeric_value":"140","unit":"V","param_group":"absolute_max"},{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"1.7","numeric_value":"1.7","unit":"W","param_group":"absolute_max"},{"key":"Ps_max","display_name":"Screen Dissipation (max)","value":"0.5","numeric_value":"0.5","unit":"W","param_group":"absolute_max"},{"key":"Ik_max","display_name":"Cathode Current (max)","value":"18","numeric_value":"18","unit":"mA","param_group":"absolute_max"},{"key":"Vhk_max","display_name":"Heater-to-Cathode Voltage (max)","value":"120","numeric_value":"120","unit":"V","param_group":"absolute_max"},{"key":"Rg_max","display_name":"Max Grid Resistor","value":"3","numeric_value":"3","unit":"MΩ","param_group":"absolute_max"},{"key":"Va","display_name":"Anode Voltage (typical)","value":"180","numeric_value":"180","unit":"V","param_group":"typical_operating"},{"key":"Vs","display_name":"Screen Voltage (typical)","value":"120","numeric_value":"120","unit":"V","param_group":"typical_operating"},{"key":"Vg","display_name":"Grid 1 Bias Voltage","value":"-2","numeric_value":"-2","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"7.7","numeric_value":"7.7","unit":"mA","param_group":"typical_operating"},{"key":"mAs","display_name":"Screen Current","value":"2.4","numeric_value":"2.4","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"400000","numeric_value":"400000","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"5.1","numeric_value":"5.1","unit":"mA/V","param_group":"typical_operating"},{"key":"Cgp","display_name":"Grid-to-Plate Capacitance","value":"<0.02","numeric_value":null,"unit":"pF","param_group":"capacitances"},{"key":"Cgk","display_name":"Grid-to-Cathode Capacitance","value":"4.0","numeric_value":"4","unit":"pF","param_group":"capacitances"},{"key":"Cak","display_name":"Anode-to-Cathode Capacitance","value":"3.1","numeric_value":"3.1","unit":"pF","param_group":"capacitances"},{"key":null,"display_name":"Vg(b) max (Boosted Screen Voltage)","value":"300","numeric_value":"300","unit":"V","param_group":null},{"key":null,"display_name":"Va(b) max (Boosted Anode Voltage)","value":"300","numeric_value":"300","unit":"V","param_group":null},{"key":null,"display_name":"rg1 (Grid Input Resistance at 50 Mc/s)","value":"25000","numeric_value":"25000","unit":"Ω","param_group":null},{"key":null,"display_name":"Req (Equivalent Noise Resistance)","value":"2000","numeric_value":"2000","unit":"Ω","param_group":null},{"key":null,"display_name":"μg2g1","value":"35","numeric_value":"35","unit":"—","param_group":null},{"key":null,"display_name":"-Vg1 max (Grid 1 Bias max)","value":"50","numeric_value":"50","unit":"V","param_group":null}]},{"section_number":2,"section_label":"Triode Strapped","tube_type_key":"small_signal_triode","specs":[{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"1.7","numeric_value":"1.7","unit":"W","param_group":"absolute_max"},{"key":"Ik_max","display_name":"Cathode Current (max)","value":"18","numeric_value":"18","unit":"mA","param_group":"absolute_max"},{"key":"Va","display_name":"Anode Voltage (typical)","value":"120","numeric_value":"120","unit":"V","param_group":"typical_operating"},{"key":"Vg","display_name":"Grid 1 Bias Voltage","value":"-2","numeric_value":"-2","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"10","numeric_value":"10","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"5200","numeric_value":"5200","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"6.8","numeric_value":"6.8","unit":"mA/V","param_group":"typical_operating"},{"key":"mu","display_name":"Amplification Factor (μ)","value":"35","numeric_value":"35","unit":"—","param_group":"typical_operating"},{"key":null,"display_name":"Req (Equivalent Noise Resistance)","value":"900","numeric_value":"900","unit":"Ω","param_group":null}]}],"synced_at":"2026-04-07T19:08:17.889Z"}