{"type_number":"UCC85","canonical_url":"https://tubeofile.com/tubes/UCC85","manufacturer":"Philips/Mullard","tube_type_key":"small_signal_triode","tube_type_display_name":"Small Signal Triode","base_name":"Noval","description":"R.F. double triode intended for use as R.F. and A.F. amplifier and self-oscillating mixer, primarily designed for FM/VHF front-end stages. 100 mA series-heater version of the ECC85, for series-string AC/DC receivers.","is_directly_heated":false,"completeness":"high","notes":["Series-heater (100 mA) version of the ECC85. Electrically identical sections — only the heater voltage/current differs (19 V at 100 mA vs 6.3 V at 435 mA).","The two triode sections are nominally identical but the datasheet provides separate RF amplifier and self-oscillating mixer operating conditions at different bias points.","An internal screening plate between the two sections provides inter-section shielding for VHF stability.","Pin 9 is connected to the internal screen/shield — it should be grounded for proper inter-section isolation.","6ER5 is the American RETMA designation for the UCC85."],"references":["https://frank.pocnet.net/sheets/010/u/UCC85.pdf"],"source_urls":{"r_type":null,"tdsl":"https://tdsl.duncanamps.com/show.php?des=UCC85","radiomuseum":"https://www.radiomuseum.org/tubes/tube_ucc85.html"},"raw_equivalents":["6ER5"],"equivalents":[],"similar":[{"type_number":"6AQ8","reason":"American designation of ECC85 — 6.3 V parallel heater, not series-string compatible","has_detail_page":false},{"type_number":"ECC85","reason":"Identical electricals but 6.3 V parallel heater — not a drop-in in series-string heater circuits","has_detail_page":true},{"type_number":"HCC85","reason":"150 mA series-heater variant (17.5 V) — different heater series, not interchangeable","has_detail_page":true},{"type_number":"PCC85","reason":"300 mA series-heater variant (9 V) — different heater series, not interchangeable","has_detail_page":true}],"pins":[{"pin_number":"1","function":"Anode 2","function_code":"a2","notes":null},{"pin_number":"2","function":"Control Grid 2","function_code":"g1_2","notes":null},{"pin_number":"3","function":"Cathode 2","function_code":"k2","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":"Anode 1","function_code":"a1","notes":null},{"pin_number":"7","function":"Control Grid 1","function_code":"g1_1","notes":null},{"pin_number":"8","function":"Cathode 1","function_code":"k1","notes":null},{"pin_number":"9","function":"Internal Screen/Shield","function_code":"ia","notes":null}],"specs":[{"key":"Vh","display_name":"Heater Voltage","value":"19","numeric_value":"19","unit":"V","param_group":"heater"},{"key":"Ah","display_name":"Heater Current","value":"0.1","numeric_value":"0.1","unit":"A","param_group":"heater"}],"sections":[{"section_number":1,"section_label":"Triode","tube_type_key":"small_signal_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":"2.5","numeric_value":"2.5","unit":"W","param_group":"absolute_max"},{"key":"Ik_max","display_name":"Cathode Current (max)","value":"15","numeric_value":"15","unit":"mA","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":"Vg","display_name":"Grid 1 Bias Voltage","value":"-2.7","numeric_value":"-2.7","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"10","numeric_value":"10","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"9016","numeric_value":"9016","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"6.1","numeric_value":"6.1","unit":"mA/V","param_group":"typical_operating"},{"key":"mu","display_name":"Amplification Factor (μ)","value":"55","numeric_value":"55","unit":"—","param_group":"typical_operating"},{"key":"Cgp","display_name":"Grid-to-Plate Capacitance","value":"1.5","numeric_value":"1.5","unit":"pF","param_group":"capacitances"},{"key":"Cgk","display_name":"Grid-to-Cathode Capacitance","value":"3.1","numeric_value":"3.1","unit":"pF","param_group":"capacitances"},{"key":"Cak","display_name":"Anode-to-Cathode Capacitance","value":"0.17","numeric_value":"0.17","unit":"pF","param_group":"capacitances"}]}],"synced_at":"2026-04-07T12:52:01.346Z"}