{"type_number":"7236","canonical_url":"https://tubeofile.com/tubes/7236","manufacturer":"Tung-Sol","tube_type_key":"power_triode","tube_type_display_name":"Power Triode","base_name":"Octal","description":"Twin power triode designed for long-life service as a series pass regulator and power amplifier in computer equipment. Originally developed by Tung-Sol to drive spindle motors of computer tape drives. Has the ability to pass large currents with a low voltage drop. Widely used in OTL headphone amplifiers.","is_directly_heated":false,"completeness":"high","notes":["The 7236 has poor heater-to-cathode insulation compared to other regulator-family tubes (6AS7, 6080, 5998, 6528). Some specimens break down at 150 V Vhk. Use caution in circuits with elevated cathode voltages.","Often described as a 'computer-rated 5998' but differs electrically: lower mu (4.8 vs 5.4) and lower gm (12,500 vs 15,500 micromhos) than the 5998, with a higher max plate voltage (300 V vs 250 V).","5998A is the direct equivalent (same ratings). The 5998 (non-A) and 421A have similar pinout but different ratings — not drop-in equivalents.","The 6AS7/6080 family shares the same pinout and heater but has significantly lower mu (2.0) and max plate voltage (250–275 V). Substitution works in many circuits but operating point will shift.","Forced air cooling is necessary to stay within the 150°C maximum bulb temperature rating."],"references":["https://frank.pocnet.net/sheets/127/7/7236.pdf","http://www.tubebooks.org/tubedata/7236_TS.PDF"],"source_urls":{"r_type":null,"tdsl":"https://tdsl.duncanamps.com/show.php?des=7236","radiomuseum":"https://www.radiomuseum.org/tubes/tube_7236.html"},"raw_equivalents":["5998A","6080WB"],"equivalents":[],"similar":[{"type_number":"5998","reason":"Same Octal pinout and similar characteristics but different ratings (µ=5.4 vs 4.8, Va_max=250V vs 300V) — close but not identical","has_detail_page":true},{"type_number":"6080","reason":"Same Octal pinout but lower mu (2.0 vs 4.8) and lower max plate voltage (275V vs 300V) — functional substitute in many applications but not electrically identical","has_detail_page":true},{"type_number":"6AS7G","reason":"Same Octal pinout but lower mu (2.0 vs 4.8) and different ratings — works in many circuits but operating point shifts significantly","has_detail_page":true}],"pins":[{"pin_number":"1","function":"Grid (Section 2)","function_code":"g1_2","notes":null},{"pin_number":"2","function":"Plate (Section 2)","function_code":"a2","notes":null},{"pin_number":"3","function":"Cathode (Section 2)","function_code":"k2","notes":null},{"pin_number":"4","function":"Grid (Section 1)","function_code":"g1_1","notes":null},{"pin_number":"5","function":"Plate (Section 1)","function_code":"a1","notes":null},{"pin_number":"6","function":"Cathode (Section 1)","function_code":"k1","notes":null},{"pin_number":"7","function":"Heater","function_code":"h","notes":null},{"pin_number":"8","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":"2.4","numeric_value":"2.4","unit":"A","param_group":"heater"}],"sections":[{"section_number":1,"section_label":"Triode","tube_type_key":"power_triode","specs":[{"key":"Va_max","display_name":"Anode Voltage (max)","value":"300","numeric_value":"300","unit":"V","param_group":"absolute_max"},{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"15","numeric_value":"15","unit":"W","param_group":"absolute_max"},{"key":"Ik_max","display_name":"Cathode Current (max)","value":"190","numeric_value":"190","unit":"mA","param_group":"absolute_max"},{"key":"Vhk_max","display_name":"Heater-to-Cathode Voltage (max)","value":"100","numeric_value":"100","unit":"V","param_group":"absolute_max"},{"key":"Rg_max","display_name":"Max Grid Resistor","value":"0.25","numeric_value":"0.25","unit":"MΩ","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":"-14","numeric_value":"-14","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"100","numeric_value":"100","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"384","numeric_value":"384","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"12.5","numeric_value":"12.5","unit":"mA/V","param_group":"typical_operating"},{"key":"mu","display_name":"Amplification Factor (μ)","value":"4.8","numeric_value":"4.8","unit":"—","param_group":"typical_operating"},{"key":"Cgp","display_name":"Grid-to-Plate Capacitance","value":"10.0","numeric_value":"10","unit":"pF","param_group":"capacitances"},{"key":"Cin","display_name":"Input Capacitance","value":"9.0","numeric_value":"9","unit":"pF","param_group":"capacitances"},{"key":"Cout","display_name":"Output Capacitance","value":"3.5","numeric_value":"3.5","unit":"pF","param_group":"capacitances"},{"key":null,"display_name":"Plate-to-Plate Capacitance","value":"0.5","numeric_value":"0.5","unit":"pF","param_group":null},{"key":null,"display_name":"Heater-to-Cathode Capacitance","value":"11.0","numeric_value":"11","unit":"pF","param_group":null}]}],"synced_at":"2026-04-07T12:31:07.301Z"}