{"type_number":"ECH83","canonical_url":"https://tubeofile.com/tubes/ECH83","manufacturer":"Philips","tube_type_key":"triode_hexode","tube_type_display_name":"Triode-Hexode","base_name":"Noval","description":"Triode-heptode frequency converter designed for use as mixer in car radio sets and as sync separator in TV receivers. Noval (B9A) base. Reportedly internally identical to the ECH81 but stamped with different ratings depending on application voltage. Higher maximum ratings than ECH81.","is_directly_heated":false,"completeness":"high","notes":["ECH81 and ECH83 are reportedly identical internally — only the stamp differs.","Triode and heptode sections share a common cathode.","Triode grid bias obtained by grid current biasing (Rg = 47 kohm).","Heptode grid No. 1 bias obtained by grid current biasing (Rg1 = 1 Mohm).","Conversion conductance Sc = 220 uA/V at Va=12.6V, up to 750 uA/V at higher voltages."],"references":["https://frank.pocnet.net/sheets/010/e/ECH83.pdf"],"source_urls":{"r_type":null,"tdsl":"https://tdsl.duncanamps.com/show.php?des=ECH83","radiomuseum":"https://www.radiomuseum.org/tubes/tube_ech83.html"},"raw_equivalents":["6DS8"],"equivalents":[{"type_number":"6DS8","equivalence_type":"direct","notes":null}],"similar":[{"type_number":"ECH81","reason":"Same Noval base and pinout — reportedly identical internally, only stamped differently","has_detail_page":true},{"type_number":"HCH81","reason":"12.6 V heater version — same pinout but different heater voltage","has_detail_page":true},{"type_number":"UCH81","reason":"Series-heater version (19 V / 100 mA) — same pinout but different heater voltage","has_detail_page":true}],"pins":[{"pin_number":"1","function":"Heptode Anode","function_code":"a2","notes":null},{"pin_number":"2","function":"Heptode Screen Grid (g2+g4)","function_code":"g2","notes":null},{"pin_number":"3","function":"Common Cathode, Suppressor Grid (g5)","function_code":"k","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":"Triode Anode","function_code":"a1","notes":null},{"pin_number":"7","function":"Heptode Signal Grid (g1)","function_code":"g1","notes":null},{"pin_number":"8","function":"Triode Grid / Heptode Oscillator Grid (g3)","function_code":"g3","notes":null},{"pin_number":"9","function":"Internal shield","function_code":"ia","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":"Triode (Oscillator)","tube_type_key":"small_signal_triode","specs":[{"key":"Va","display_name":"Anode Voltage (typical)","value":"12.6","numeric_value":"12.6","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"0.75","numeric_value":"0.75","unit":"mA","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"1.4","numeric_value":"1.4","unit":"mA/V","param_group":"typical_operating"},{"key":"mu","display_name":"Amplification Factor (μ)","value":"18.3","numeric_value":"18.3","unit":"—","param_group":"typical_operating"}]},{"section_number":2,"section_label":"Heptode (Mixer)","tube_type_key":"hexode","specs":[{"key":"Va","display_name":"Anode Voltage (typical)","value":"12.6","numeric_value":"12.6","unit":"V","param_group":"typical_operating"},{"key":"Vs","display_name":"Screen Voltage (typical)","value":"12.6","numeric_value":"12.6","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"0.55","numeric_value":"0.55","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"500000","numeric_value":"500000","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"0.22","numeric_value":"0.22","unit":"mA/V","param_group":"typical_operating"}]}],"synced_at":"2026-04-07T19:07:35.576Z"}