{"type_number":"6DA4","canonical_url":"https://tubeofile.com/tubes/6DA4","manufacturer":"General Electric","tube_type_key":"diode","tube_type_display_name":"Diode","base_name":"Octal","description":"Single indirectly-heated diode for TV horizontal-deflection damper service. Designed to withstand high pulse voltages between heater and cathode and high inverse pulse voltages between plate and cathode. Particularly suited for autotransformer deflection systems where high pulse voltages are applied to the cathode.","is_directly_heated":false,"completeness":"high","notes":["Designed specifically for TV horizontal-deflection damper service; operation as a power rectifier is not recommended.","PIV rating of 4400V applies for a 525-line, 30-frame television system where the duty cycle of the voltage pulse does not exceed 15% of one scanning cycle.","Heater negative with respect to cathode: DC component max 900V, total DC and peak max 4400V. Heater positive with respect to cathode: DC component max 100V, total DC and peak max 300V.","Pin 1 is an internal connection (connects to shell); pin 2 is an internal connection. Socket terminals 1, 2, 4, and 6 should not be used.","The 12D4 and 17D4 are electrically identical (same ratings) but have different heater voltages and a controlled heater warm-up characteristic for series-connected heater strings.","6DA4A is a different-rating variant; verify suitability before substitution."],"references":["https://tube-data.com/sheets/093/6/6DA4.pdf"],"source_urls":{"r_type":null,"tdsl":"https://tdsl.duncanamps.com/show.php?des=6DA4","radiomuseum":"https://www.radiomuseum.org/tubes/tube_6da4.html"},"raw_equivalents":["6DA4A"],"equivalents":[],"similar":[{"type_number":"12D4","reason":"Identical electrically but 12.6V heater — not a drop-in replacement in TV series heater string circuits","has_detail_page":true},{"type_number":"17D4","reason":"Identical electrically but 16.8V heater — not a drop-in replacement in TV series heater string circuits","has_detail_page":false}],"pins":[{"pin_number":"1","function":"Internal Connection (shell)","function_code":"ia","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":"4","function":"No Connection","function_code":"nc","notes":null},{"pin_number":"5","function":"Plate","function_code":"a","notes":null},{"pin_number":"6","function":"No Connection","function_code":"nc","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":"Diode","tube_type_key":"diode","specs":[{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"5.5","numeric_value":"5.5","unit":"W","param_group":"absolute_max"},{"key":"Vhk_max","display_name":"Heater-to-Cathode Voltage (max)","value":"4400","numeric_value":"4400","unit":"V","param_group":"absolute_max"},{"key":"PIV","display_name":"Peak Inverse Voltage","value":"4400","numeric_value":"4400","unit":"V","param_group":"rectifier"},{"key":"Vdrop","display_name":"Voltage Drop (typical)","value":"22","numeric_value":"22","unit":"V","param_group":"rectifier"},{"key":"Idc_max","display_name":"Max DC Output Current (total, not per-anode)","value":"155","numeric_value":"155","unit":"mA","param_group":"rectifier"},{"key":"Ia_peak","display_name":"Peak Anode Current (surge)","value":"900","numeric_value":"900","unit":"mA","param_group":"rectifier"}]}],"synced_at":"2026-04-08T07:52:29.403Z"}