{"type_number":"PenA4","canonical_url":"https://tubeofile.com/tubes/PenA4","manufacturer":"Mullard","tube_type_key":"power_pentode","tube_type_display_name":"Power Pentode","base_name":"B7G","description":"High-sensitivity output pentode with 4 V indirectly-heated cathode. 7-pin base (B7). Mullard design for use in AC mains receivers. The PenA4 is equipped with a quick-heating cathode and should only be used with the IW4/350 rectifier. The PenA4 and Pen4VB have identical electrical characteristics except for heating time.","is_directly_heated":false,"completeness":"medium","notes":["Quick-heating cathode — should only be used with the IW4/350 rectifier.","Pen4VB has identical characteristics except for heating time.","Grid resistance max = 1 Mohm.","Cathode bias resistor: Rk = 145 ohms.","Range of grid voltage for 1 uA grid current: Vg1 = -0.3 to -0.8 V.","Brans lists equivalents: BL2, CV1329, D12F, EL5, PEN4VB."],"references":["https://frank.pocnet.net/sheets/153/p/PENA4.pdf"],"source_urls":{"r_type":null,"tdsl":null,"radiomuseum":"https://www.radiomuseum.org/tubes/tube_pena4.html"},"raw_equivalents":["CV1329","Pen4VB"],"equivalents":[{"type_number":"Pen4VB","equivalence_type":"direct","notes":null}],"similar":[{"type_number":"EL5","reason":"Related Philips output pentode — similar power class but different base and characteristics","has_detail_page":true}],"pins":[{"pin_number":"1","function":"No Connection","function_code":"nc","notes":null},{"pin_number":"2","function":"Control Grid (G1)","function_code":"g1","notes":null},{"pin_number":"3","function":"Auxiliary Grid (G2)","function_code":"g2","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":"Cathode","function_code":"k","notes":null},{"pin_number":"7","function":"Anode","function_code":"a","notes":null}],"specs":[{"key":"Vh","display_name":"Heater Voltage","value":"4","numeric_value":"4","unit":"V","param_group":"heater"},{"key":"Ah","display_name":"Heater Current","value":"1.95","numeric_value":"1.95","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":"9","numeric_value":"9","unit":"W","param_group":"absolute_max"},{"key":"Rg_max","display_name":"Max Grid Resistor","value":"1","numeric_value":"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":"-5.8","numeric_value":"-5.8","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"36","numeric_value":"36","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":"50000","numeric_value":"50000","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"9.5","numeric_value":"9.5","unit":"mA/V","param_group":"typical_operating"},{"key":"Rk","display_name":"Cathode Resistor (self-bias)","value":"145","numeric_value":"145","unit":"Ω","param_group":"typical_operating"},{"key":"Pout","display_name":"Output Power","value":"3.8","numeric_value":"3.8","unit":"W","param_group":"output"},{"key":"rl","display_name":"Load Impedance","value":"8000","numeric_value":"8000","unit":"Ω","param_group":"output"}]}],"synced_at":"2026-04-07T19:09:23.223Z"}