{"product_id":"5z3-vt-145-national-union-nos-nib-matched-pair-hanging-filaments-black-plates-foil-getter-usa","title":"5Z3 VT-145 NATIONAL UNION NOS NIB Matched Pair Hanging Filaments Black Plates Foil Getter USA","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cstrong\u003e5Z3 ( VT-145 ) NU NOS NIB Black Plates Hanging Filaments Foil Getter Engraved Base Tube Rectifiers Made in USA\u003c\/strong\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eDescription:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-end=\"781\" data-start=\"202\"\u003eThe \u003cstrong data-end=\"236\" data-start=\"205\"\u003eNational Union 5Z3 (VT-145)\u003c\/strong\u003e , made in the USA in the 1940s, are double half-wave rectifiers equivalent to the 5U4G, widely used in military radios, transmitters, and early audio power amplifiers. \u003cbr data-end=\"454\" data-start=\"451\"\u003eThese examples are in \u003cstrong data-end=\"539\" data-start=\"499\"\u003eNOS NIB (New Old Stock – New in Box)\u003c\/strong\u003e condition and offer fine construction details such as the \u003cstrong data-end=\"605\" data-start=\"589\"\u003eblack plates\u003c\/strong\u003e , \u003cstrong data-end=\"650\" data-start=\"609\"\u003ehanging filaments\u003c\/strong\u003e , \u003cstrong data-end=\"670\" data-start=\"655\"\u003efoil getter\u003c\/strong\u003e and \u003cstrong data-is-only-node=\"\" data-end=\"707\" data-start=\"676\"\u003eengraved base\u003c\/strong\u003e , distinctive features of National Union production of the time.\u003c\/p\u003e\n\u003cp data-end=\"970\" data-start=\"783\"\u003eTubes of this level not only represent a piece of American thermionic technology history, but are also highly appreciated for their refined and reliable sound reproduction.\u003c\/p\u003e\n\u003ch3 data-end=\"1010\" data-start=\"956\"\u003eTimbral characteristics and sound behavior\u003c\/h3\u003e\n\u003cp data-end=\"1161\" data-start=\"1034\"\u003e\u003cstrong data-end=\"1044\" data-start=\"1034\"\u003eBass:\u003c\/strong\u003e Full and deep, with excellent control. It provides a stable and authoritative foundation that gives solidity to the entire range.\u003c\/p\u003e\n\u003cp data-end=\"1277\" data-start=\"1164\"\u003e\u003cstrong data-end=\"1173\" data-start=\"1164\"\u003eMids:\u003c\/strong\u003e Transparent, rich, and musical. Voices and acoustic instruments emerge with realism and naturalness.\u003c\/p\u003e\n\u003cp data-end=\"1401\" data-start=\"1280\"\u003e\u003cstrong data-end=\"1289\" data-start=\"1280\"\u003eHighs:\u003c\/strong\u003e extended and fluid, with a balanced, never fatiguing brilliance. They offer airiness and detail without harshness.\u003c\/p\u003e\n\u003cp data-end=\"1512\" data-start=\"1404\"\u003e\u003cstrong data-end=\"1417\" data-start=\"1404\"\u003eDynamics:\u003c\/strong\u003e prompt and incisive, with the ability to follow both rapid transients and complex passages.\u003c\/p\u003e\n\u003cp data-end=\"1616\" data-start=\"1515\"\u003e\u003cstrong data-end=\"1530\" data-start=\"1515\"\u003eSoundstage:\u003c\/strong\u003e wide and three-dimensional, with clear separation of instruments and excellent depth.\u003c\/p\u003e\n\u003ch3 data-end=\"2004\" data-start=\"1971\"\u003e🎧 Use in Hi-Fi amplifiers\u003c\/h3\u003e\n\u003cp data-end=\"2283\" data-start=\"2006\"\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cmeta charset=\"utf-8\"\u003e Perfect for vintage tube power amplifiers and hi-fi preamplifiers, where they ensure stable power supply and an elegant, refined sonic impact.\u003cbr\u003e\u003c\/p\u003e\n\u003ch3 data-end=\"2340\" data-start=\"2290\"\u003e🎸 Use in musical instrument amplifiers\u003c\/h3\u003e\n\u003cp data-end=\"2639\" data-start=\"2342\"\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cmeta charset=\"utf-8\"\u003e Ideal for historic organs and amplifiers, they provide reliable power and a rich, robust, musical sound with a warm, authentic character.\u003cbr\u003e\u003c\/p\u003e\n\u003ch3 data-end=\"2681\" data-start=\"2646\"\u003e🎯 Note for audiophiles and technicians\u003c\/h3\u003e\n\u003cp data-end=\"3065\" data-start=\"2683\"\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cmeta charset=\"utf-8\"\u003e The \u003cstrong data-end=\"2111\" data-start=\"2067\"\u003e5Z3 (VT-145) National Union Black Plates\u003c\/strong\u003e with \u003cstrong data-end=\"2164\" data-start=\"2116\"\u003esuspended filaments, foil getter and engraved base\u003c\/strong\u003e represent some of the most fascinating and sought-after versions of this historic grinder.\u003cbr data-end=\"2266\" data-start=\"2263\"\u003eA perfect option for those looking for \u003cstrong data-end=\"2361\" data-start=\"2300\"\u003etechnical reliability, musicality and collectible value\u003c\/strong\u003e , suitable for both philological restorations and high-end hi-fi systems.\u003cbr\u003e\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eTest Results:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cspan\u003eTubes tested on \u003cstrong\u003eFunke W19\u003c\/strong\u003e Tube tester:\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003e\u003cstrong\u003eVoltage Test:\u003c\/strong\u003e Va = 100V, Vf = 5V\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003eGood from: Ia = 78 mA\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003eAverage 100% Ia = 120 mA\u003c\/span\u003e\u003cbr\u003e\u003cstrong\u003eTest Result: VERY STRONG\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003ePlate current\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eValve 1:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eSection 1:\u003c\/strong\u003e Ia = 102 mA\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eSection 2:\u003c\/strong\u003e Ia = 102 mA\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eValve 2:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eSection 1:\u003c\/strong\u003e Ia = 105 mA\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eSection 2:\u003c\/strong\u003e Ia = 110 mA\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cspan\u003ePlate current:\u003c\/span\u003e\u003cstrong\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eAdditional Tests\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eOperation:\u003c\/strong\u003e Stable tube, silent in operation and suitable for providing a regular and well-controlled power supply. Tested with Funke W19 tube tester.\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eOutput Quality:\u003c\/strong\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cspan\u003eExcellent – Very strong and stable output, no fluctuations.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eShort circuits and GAS:\u003c\/strong\u003e Absent.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eConditions:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eConditions:\u003cspan\u003e \u003c\/span\u003e\u003c\/strong\u003eNOS - NIB - New Old Stock, New In Box - Tested and working - Supplied in original box.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eFunctionality:\u003c\/strong\u003e Fully functional.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eCosmetic condition:\u003c\/strong\u003e \u003cspan\u003eExcellent – Excellently preserved lettering, minimal signs of wear. See photos for details.\u003c\/span\u003e\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eManufacturing Code:\u003cspan\u003e \u003c\/span\u003e\u003c\/strong\u003eAbsent - Year of manufacture obtained from the internal structure - Manufactured in the 1940s\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003ca rel=\"noopener\" title=\"Why our tubes are different – the VTT protocol that improves sound, reliability and durability\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" target=\"_blank\"\u003e\u003cstrong\u003eFind out why our valves are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"NATIONAL UNION","offers":[{"title":"Default Title","offer_id":55337679815004,"sku":"03074","price":159.8,"currency_code":"EUR","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_efac137b-78da-4b72-b0fd-5b4b02ff0fbc.jpg?v=1756314752","url":"https:\/\/vacuumtubestreasures.com\/en-ie\/products\/5z3-vt-145-national-union-nos-nib-matched-pair-hanging-filaments-black-plates-foil-getter-usa","provider":"Vacuum Tubes Treasures","version":"1.0","type":"link"}