{"type_number":"6K8","canonical_url":"https://tubeofile.com/tubes/6K8","manufacturer":"RCA","tube_type_key":"triode_hexode","tube_type_display_name":"Triode-Hexode","base_name":"Octal","description":"Triode-hexode frequency converter (oscillator-mixer) designed for superheterodyne receiver applications. Octal base with top-cap grid connection. Contains a triode oscillator section and a hexode mixer section in a single envelope.","is_directly_heated":false,"completeness":"high","notes":["Triode-hexode converter — the triode section serves as the local oscillator, the hexode section as the mixer. The two sections share an internal electron coupling.","Top-cap connection on the metal envelope version for the hexode signal grid (g1 of hexode section).","Raytheon data: Hexode section — Va=100V, Vs=100V, Vg=-3V, Ia=3.8mA, gm=3000 (conversion gm).","Philips interchange: CV1945 is the British military designation.","Sams substitution guide lists WTT128 and 6P17 as substitutes."],"references":["https://frank.pocnet.net/sheets/127/6/6K8.pdf","https://tdsl.duncanamps.com/show.php?des=6K8"],"source_urls":{"r_type":null,"tdsl":"https://tdsl.duncanamps.com/show.php?des=6K8","radiomuseum":"https://www.radiomuseum.org/tubes/tube_6k8.html"},"raw_equivalents":["6K8G","6K8GT","CV1945","VT167A"],"equivalents":[],"similar":[{"type_number":"6SA7","reason":"Pentagrid converter on Octal base — different converter topology (single-section vs triode-hexode)","has_detail_page":true},{"type_number":"ECH35","reason":"European triode-hexode converter but Rimlock base — not pin-compatible","has_detail_page":true}],"pins":[{"pin_number":"1","function":"Shell (metal type)","function_code":"nc","notes":null},{"pin_number":"2","function":"Heater","function_code":"h","notes":null},{"pin_number":"3","function":"Hexode Anode","function_code":"a1","notes":null},{"pin_number":"4","function":"Hexode Screen Grid","function_code":"g2","notes":null},{"pin_number":"5","function":"Triode Anode","function_code":"a2","notes":null},{"pin_number":"6","function":"Triode Grid","function_code":"g1_2","notes":null},{"pin_number":"7","function":"Heater","function_code":"h","notes":null},{"pin_number":"8","function":"Cathode","function_code":"k","notes":null},{"pin_number":"TC","function":"Hexode Signal Grid (g1)","function_code":"g1_1","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":"Hexode Mixer","tube_type_key":"hexode","specs":[{"key":"Va","display_name":"Anode Voltage (typical)","value":"100","numeric_value":"100","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":"3.8","numeric_value":"3.8","unit":"mA","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"0.55","numeric_value":"0.55","unit":"mA/V","param_group":"typical_operating"}]},{"section_number":2,"section_label":"Triode Oscillator","tube_type_key":"small_signal_triode","specs":[{"key":"Va","display_name":"Anode Voltage (typical)","value":"100","numeric_value":"100","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"3.5","numeric_value":"3.5","unit":"mA","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"3.0","numeric_value":"3","unit":"mA/V","param_group":"typical_operating"}]}],"synced_at":"2026-04-07T12:26:08.312Z"}