{"type_number":"6DQ4","canonical_url":"https://tubeofile.com/tubes/6DQ4","manufacturer":"Tung-Sol","tube_type_key":"diode","tube_type_display_name":"Diode","base_name":"Octal","description":"Half-wave vacuum rectifier (heater-cathode type diode) designed for use as a horizontal frequency damper in television receivers. Can withstand high voltage pulses of horizontal line frequency between cathode and both heater and plate elements, as encountered in direct-drive circuits. Tung-Sol design, dated July 1962.","is_directly_heated":false,"completeness":"high","notes":["Short intermediate-shell 5-pin Octal base (B5-85), basing diagram JEDEC 4CG, outline drawing JEDEC 9-41. T-9 glass envelope.","Socket terminals 1, 2, 4, and 6 shall not be used as tie points.","PIV rating of 5500V applies for a 525-line, 30-frame TV system where the duty cycle of the voltage pulse does not exceed 15% of one scanning cycle (10 µs).","Maximum peak heater-cathode voltage: 5500V (heater negative total DC+peak, DC component max 900V) / 300V (heater positive total DC+peak, DC component max 100V).","Operation of this tube as a power rectifier is not recommended by the manufacturer.","Highest PIV rating (5500V) among the JEDEC 4CG family of Octal damper diodes (6AX4=4400V, 6DA4=4400V, 6DM4=5000V)."],"references":["https://frank.pocnet.net/sheets/127/6/6DQ4.pdf"],"source_urls":{"r_type":null,"tdsl":"https://tdsl.duncanamps.com/show.php?des=6DQ4","radiomuseum":"https://www.radiomuseum.org/tubes/tube_6dq4.html"},"raw_equivalents":[],"equivalents":[],"similar":[{"type_number":"6AS4","reason":"Radiomuseum lists as normally replaceable-slightly different — same Octal base family","has_detail_page":false},{"type_number":"6AX4","reason":"Same Octal base and JEDEC 4CG pinout but lower ratings (PIV 4400V vs 5500V, Ia 137mA vs 175mA, Pa 5.0W vs 6.0W)","has_detail_page":true},{"type_number":"6DA4","reason":"Same Octal base and JEDEC 4CG pinout but lower ratings (PIV 4400V vs 5500V, Ia 155mA vs 175mA, Pa 5.5W vs 6.0W)","has_detail_page":true},{"type_number":"6DE4","reason":"Same Octal base and pinout, similar damper diode — verify ratings before substitution","has_detail_page":true},{"type_number":"6DM4","reason":"Same Octal base and JEDEC 4CG pinout, similar ratings (PIV 5000V vs 5500V, Ia 175mA, Pa 6.5W vs 6.0W)","has_detail_page":true},{"type_number":"6DT4","reason":"Radiomuseum lists as normally replaceable-slightly different","has_detail_page":false}],"pins":[{"pin_number":"1","function":"Internal Connection","function_code":"ic","notes":null},{"pin_number":"2","function":"Internal Connection","function_code":"ic","notes":null},{"pin_number":"3","function":"Cathode","function_code":"k","notes":null},{"pin_number":"5","function":"Plate","function_code":"a","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":"1.2","numeric_value":"1.2","unit":"A","param_group":"heater"}],"sections":[{"section_number":1,"section_label":"Damper Diode","tube_type_key":"diode","specs":[{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"6","numeric_value":"6","unit":"W","param_group":"absolute_max"},{"key":"Vhk_max","display_name":"Heater-to-Cathode Voltage (max)","value":"5500","numeric_value":"5500","unit":"V","param_group":"absolute_max"},{"key":"PIV","display_name":"Peak Inverse Voltage","value":"5500","numeric_value":"5500","unit":"V","param_group":"rectifier"},{"key":"Vdrop","display_name":"Voltage Drop (typical)","value":"32","numeric_value":"32","unit":"V","param_group":"rectifier"},{"key":"Idc_max","display_name":"Max DC Output Current (total, not per-anode)","value":"175","numeric_value":"175","unit":"mA","param_group":"rectifier"},{"key":"Ia_peak","display_name":"Peak Anode Current (surge)","value":"1000","numeric_value":"1000","unit":"mA","param_group":"rectifier"}]}],"synced_at":"2026-04-08T07:52:42.728Z"}