{"type_number":"22DE4","canonical_url":"https://tubeofile.com/tubes/22DE4","manufacturer":"Tung-Sol","tube_type_key":"rectifier","tube_type_display_name":"Rectifier","base_name":"Octal","description":"Half-wave vacuum rectifier designed for use as a damper diode in horizontal-deflection circuits of black-and-white television receivers. Glass-Octal type with coated unipotential cathode. Except for heater ratings and heater warm-up time, the 22DE4 is identical to the 6DE4 and 17DE4.","is_directly_heated":false,"completeness":"high","notes":["Tung-Sol datasheet, December 1, 1962, Plate #6347. JEDEC Group 1, B5-85 glass bulb, short intermediate-shell 5-pin Octal with external barriers.","Pins 1, 4, and 6 are omitted. Pin 2 is an internal connection — do not use as a tie point.","PIV rating of 5500V applies for operation in a 525-line, 30-frame system per FCC standards; duty cycle of voltage pulse must not exceed 15% of one scanning cycle.","Heater-cathode voltage: heater negative max 5500V peak (DC component must not exceed 900V); heater positive max 300V peak (DC component must not exceed 100V).","Heater warm-up time approximately 11.0 seconds (series-string operation).","Interelectrode capacitances (without external shield): plate-to-heater-and-cathode 8.5 pF, cathode-to-heater-and-plate 11.5 pF, heater-to-cathode 4 pF.","Tube voltage drop (Vdrop) is not stated as a discrete figure in the Tung-Sol datasheet. Derived from the Average Plate Characteristic curve (Ef=22.4V) at the maximum DC plate current of 180 mA, where plate voltage reads approximately 20 V."],"references":["https://frank.pocnet.net/sheets/127/2/22DE4.pdf"],"source_urls":{"r_type":null,"tdsl":"https://tdsl.duncanamps.com/show.php?des=22DE4","radiomuseum":"https://www.radiomuseum.org/tubes/tube_22de4.html"},"raw_equivalents":[],"equivalents":[],"similar":[{"type_number":"17DE4","reason":"Identical except 16.8V heater — not a drop-in due to different heater voltage","has_detail_page":false},{"type_number":"6AX4","reason":"Same function (half-wave Octal damper diode) but lower PIV (4400V vs 5500V) and different heater voltage","has_detail_page":true},{"type_number":"6DE4","reason":"Identical except 6.3V heater — not a drop-in due to different heater voltage","has_detail_page":true}],"pins":[{"pin_number":"2","function":"Internal Connection — Do Not Use","function_code":"ic","notes":null},{"pin_number":"3","function":"Cathode","function_code":"k","notes":null},{"pin_number":"5","function":"Plate (Anode)","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":"22.4","numeric_value":"22.4","unit":"V","param_group":"heater"},{"key":"Ah","display_name":"Heater Current","value":"0.45","numeric_value":"0.45","unit":"A","param_group":"heater"}],"sections":[{"section_number":1,"section_label":"Damper Diode","tube_type_key":"rectifier","specs":[{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"6.5","numeric_value":"6.5","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":"20","numeric_value":"20","unit":"V","param_group":"rectifier"},{"key":"Idc_max","display_name":"Max DC Output Current (total, not per-anode)","value":"180","numeric_value":"180","unit":"mA","param_group":"rectifier"},{"key":"Ia_peak","display_name":"Peak Anode Current (surge)","value":"1100","numeric_value":"1100","unit":"mA","param_group":"rectifier"}]}],"synced_at":"2026-04-09T05:16:24.442Z"}