{"type_number":"6SJ7","canonical_url":"https://tubeofile.com/tubes/6SJ7","manufacturer":"RCA","tube_type_key":"ss_pentode","tube_type_display_name":"Small Signal Pentode","base_name":"Octal","description":"Sharp-cutoff pentode for use as RF amplifier, IF amplifier, detector, or audio voltage amplifier. Metal-envelope tube with octal base, introduced 1938. Successor to the 6J7 with improved shielding and lower interelectrode capacitances.","is_directly_heated":false,"completeness":"high","notes":["Pin 1 is the metal shell connection (internal shield), which should be grounded for proper shielding. On the 6SJ7GT glass version, pin 1 is the cathode connection only (no shell).","The 5693 is a ruggedised long-life variant (10,000+ hour rating) with identical electrical characteristics but tighter manufacturing tolerances.","12SJ7 is the 12.6V heater version (0.15A); electrically identical sections but not a drop-in substitute due to different heater requirements.","Triode connection is made by tying grids 2 and 3 to the anode. The RCA datasheet provides full triode-connected operating data at two plate voltage conditions.","The suppressor grid (g3) must be connected to cathode in pentode operation (internally connected on some variants, externally on pin 3 for the 6SJ7 metal type).","Heater-to-cathode voltage must not exceed 90V (either polarity). Keep heater-cathode potential difference as low as possible."],"references":["https://frank.pocnet.net/sheets/049/6/6SJ7.pdf","https://frank.pocnet.net/sheets/127/6/6SJ7.pdf"],"source_urls":{"r_type":"http://www.r-type.org/exhib/aaa0124.htm","tdsl":"https://tdsl.duncanamps.com/show.php?des=6SJ7","radiomuseum":"https://www.radiomuseum.org/tubes/tube_6sj7.html"},"raw_equivalents":["6SJ7GT","6SJ7GTX","6SJ7GTY","6SJ7Y","6SJ7W","6SJ7WGT","CV591","CV592","VT-116","VT-116A","5693"],"equivalents":[],"similar":[{"type_number":"7C7","reason":"Loctal-base equivalent — same electrical characteristics but different base (Loctal vs Octal)","has_detail_page":true},{"type_number":"EF37A","reason":"Similar sharp-cutoff pentode with comparable characteristics but different base type (British Octal B8B vs American Octal)","has_detail_page":true}],"pins":[{"pin_number":"1","function":"Shell (Metal type) / Cathode (GT type)","function_code":"k","notes":null},{"pin_number":"2","function":"Heater","function_code":"h","notes":null},{"pin_number":"3","function":"Suppressor Grid","function_code":"g3","notes":null},{"pin_number":"4","function":"Control Grid","function_code":"g1","notes":null},{"pin_number":"5","function":"Cathode","function_code":"k","notes":null},{"pin_number":"6","function":"Screen Grid","function_code":"g2","notes":null},{"pin_number":"7","function":"Heater","function_code":"h","notes":null},{"pin_number":"8","function":"Anode","function_code":"a","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":"0.3","numeric_value":"0.3","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":"300","numeric_value":"300","unit":"V","param_group":"absolute_max"},{"key":"Vs_max","display_name":"Screen Voltage (max)","value":"125","numeric_value":"125","unit":"V","param_group":"absolute_max"},{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"2.5","numeric_value":"2.5","unit":"W","param_group":"absolute_max"},{"key":"Ps_max","display_name":"Screen Dissipation (max)","value":"0.7","numeric_value":"0.7","unit":"W","param_group":"absolute_max"},{"key":"Vhk_max","display_name":"Heater-to-Cathode Voltage (max)","value":"90","numeric_value":"90","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":"250","numeric_value":"250","unit":"V","param_group":"typical_operating"},{"key":"Vs","display_name":"Screen Voltage (typical)","value":"100","numeric_value":"100","unit":"V","param_group":"typical_operating"},{"key":"Vg","display_name":"Grid 1 Bias Voltage","value":"-3","numeric_value":"-3","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"3.0","numeric_value":"3","unit":"mA","param_group":"typical_operating"},{"key":"mAs","display_name":"Screen Current","value":"0.8","numeric_value":"0.8","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"1500000","numeric_value":"1500000","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"1.65","numeric_value":"1.65","unit":"mA/V","param_group":"typical_operating"},{"key":"Cgp","display_name":"Grid-to-Plate Capacitance","value":"0.005","numeric_value":"0.005","unit":"pF","param_group":"capacitances"},{"key":"Cgk","display_name":"Grid-to-Cathode Capacitance","value":"6","numeric_value":"6","unit":"pF","param_group":"capacitances"},{"key":"Cak","display_name":"Anode-to-Cathode Capacitance","value":"7","numeric_value":"7","unit":"pF","param_group":"capacitances"},{"key":null,"display_name":"Grid Voltage (cutoff)","value":"-9","numeric_value":"-9","unit":"V","param_group":null}]},{"section_number":2,"section_label":"Triode Strapped","tube_type_key":"small_signal_triode","specs":[{"key":"Va_max","display_name":"Anode Voltage (max)","value":"250","numeric_value":"250","unit":"V","param_group":"absolute_max"},{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"2.5","numeric_value":"2.5","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":"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":"9.2","numeric_value":"9.2","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"7600","numeric_value":"7600","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"2.5","numeric_value":"2.5","unit":"mA/V","param_group":"typical_operating"},{"key":"mu","display_name":"Amplification Factor (μ)","value":"19","numeric_value":"19","unit":"—","param_group":"typical_operating"},{"key":"Cgp","display_name":"Grid-to-Plate Capacitance","value":"2.8","numeric_value":"2.8","unit":"pF","param_group":"capacitances"},{"key":"Cgk","display_name":"Grid-to-Cathode Capacitance","value":"3.4","numeric_value":"3.4","unit":"pF","param_group":"capacitances"},{"key":"Cak","display_name":"Anode-to-Cathode Capacitance","value":"11","numeric_value":"11","unit":"pF","param_group":"capacitances"}]}],"synced_at":"2026-04-07T12:29:03.105Z"}