{"type_number":"6HJ5","canonical_url":"https://tubeofile.com/tubes/6HJ5","manufacturer":null,"tube_type_key":"beam_tetrode","tube_type_display_name":"Beam Tetrode","base_name":"Compactron","description":"Beam power tube designed for use as a horizontal-deflection amplifier in television receivers. Features a compactron base with dual grid pins for cool operation. Can be triode-connected for audio use with mu of 4.2, comparable to a 2A3 but with an indirectly heated cathode.","is_directly_heated":false,"completeness":"medium","notes":["21HJ5 (21.5V/0.6A heater) and 30HJ5 (30V/0.45A heater) are heater-voltage variants, identical except for heater characteristics.","Pins 6 and 8 are internal connections marked 'Do Not Use' — socket clips for these pins should be omitted to improve insulation.","Grid No.1 and Grid No.2 each have dual base pins (3+11 and 5+9 respectively) for improved cooling. Grid No.3 (beam plates) also has dual pins (4+10).","An adequate bias resistor or other means is required to protect the tube in the absence of excitation.","Originally designed for TV horizontal deflection with peak plate voltages up to 7000V, but widely adopted by DIY audio builders as a triode-connected output tube."],"references":["https://frank.pocnet.net/sheets/049/6/6HJ5.pdf","https://frank.pocnet.net/sheets/084/6/6HJ5.pdf"],"source_urls":{"r_type":null,"tdsl":"https://tdsl.duncanamps.com/show.php?des=6HJ5","radiomuseum":"https://www.radiomuseum.org/tubes/tube_6hj5.html"},"raw_equivalents":["21HJ5","30HJ5"],"equivalents":[],"similar":[],"pins":[{"pin_number":"1","function":"Heater","function_code":"h","notes":null},{"pin_number":"2","function":"Cathode","function_code":"k","notes":null},{"pin_number":"3","function":"Grid No.1","function_code":"g1","notes":null},{"pin_number":"4","function":"Grid No.3 (Beam Plates)","function_code":"g3","notes":null},{"pin_number":"5","function":"Grid No.2 (Screen)","function_code":"g2","notes":null},{"pin_number":"6","function":"No Connection (internal)","function_code":"nc","notes":null},{"pin_number":"7","function":"Plate","function_code":"a","notes":null},{"pin_number":"8","function":"No Connection (internal)","function_code":"nc","notes":null},{"pin_number":"9","function":"Grid No.2 (Screen)","function_code":"g2","notes":null},{"pin_number":"10","function":"Grid No.3 (Beam Plates)","function_code":"g3","notes":null},{"pin_number":"11","function":"Grid No.1","function_code":"g1","notes":null},{"pin_number":"12","function":"Heater","function_code":"h","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":"2.25","numeric_value":"2.25","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":"770","numeric_value":"770","unit":"V","param_group":"absolute_max"},{"key":"Va_peak_max","display_name":"Peak Anode Voltage (max)","value":"7000","numeric_value":"7000","unit":"V","param_group":"absolute_max"},{"key":"Vg2_max","display_name":"Screen Voltage (max)","value":"220","numeric_value":"220","unit":"V","param_group":"absolute_max"},{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"24","numeric_value":"24","unit":"W","param_group":"absolute_max"},{"key":"Pg2_max","display_name":"Screen Dissipation (max)","value":"6","numeric_value":"6","unit":"W","param_group":"absolute_max"},{"key":"Ik_max","display_name":"Cathode Current (max)","value":"280","numeric_value":"280","unit":"mA","param_group":"absolute_max"},{"key":"Vhk_max","display_name":"Heater-to-Cathode Voltage (max)","value":"200","numeric_value":"200","unit":"V","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":"135","numeric_value":"135","unit":"V","param_group":"typical_operating"},{"key":"Vg","display_name":"Grid 1 Bias Voltage","value":"-22","numeric_value":"-22","unit":"V","param_group":"typical_operating"},{"key":"Vg2","display_name":"Screen Voltage","value":"135","numeric_value":"135","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"80","numeric_value":"80","unit":"mA","param_group":"typical_operating"},{"key":"mAg2","display_name":"Screen Current","value":"5.5","numeric_value":"5.5","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"5000","numeric_value":"5000","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"10","numeric_value":"10","unit":"mA/V","param_group":"typical_operating"}]},{"section_number":2,"section_label":"Triode Strapped","tube_type_key":"power_triode","specs":[{"key":"Va","display_name":"Anode Voltage (typical)","value":"135","numeric_value":"135","unit":"V","param_group":"typical_operating"},{"key":"Vg","display_name":"Grid 1 Bias Voltage","value":"-22","numeric_value":"-22","unit":"V","param_group":"typical_operating"},{"key":"mu","display_name":"Amplification Factor (μ)","value":"4.2","numeric_value":"4.2","unit":"—","param_group":"typical_operating"}]}],"synced_at":"2026-04-07T12:24:57.264Z"}