{"product_id":"u-s-army-technical-manual-tm-11-2121-central-office-equipment-fundamentals-1950","title":"U.S. Army Technical Manual TM 11-2121 – Central Office Equipment Fundamentals (1950)","description":"\u003cp\u003e\u003cspan\u003eOffered here is an original Department of the Army Technical Manual TM 11-2121, titled “Fundamentals (All-Relay 100-Point Dial Central Office Equipment),” dated April 1950.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThis manual covers the basic principles and operation of early electromechanical telephone switching systems used in military and civilian communications networks during the post-WWII period.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eDetails:\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan\u003eManual Number: TM 11-2121\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eDate: April 1950\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eIssued by: Department of the Army\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eSubject: All-Relay 100-Point Dial Central Office Equipment\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eType: Technical fundamentals manual\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cbr\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eHistorical Significance:\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThis manual provides foundational instruction on step-by-step telephone switching systems, which were widely used in military bases and communications infrastructure following WWII. These systems relied on relay-based switching technology and formed the backbone of early telephone networks.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eA good addition for collectors of:\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan\u003eSignal Corps and communications equipment\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eEarly telephone and switching systems\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eMilitary technical documentation\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cbr\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eCondition:\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan\u003eComplete and intact\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eLight age-related wear and toning\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eMinor handling marks consistent with use\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eClean and readable\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cbr\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003ePlease review photos for full condition details.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eCollector Appeal:\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan\u003eOriginal government-issued manual\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eTechnical reference for early communications systems\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eGood companion piece to other central office manuals\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e \u003c\/p\u003e","brand":"Whiskey Rebellion Antiques","offers":[{"title":"Default Title","offer_id":42866946506829,"sku":null,"price":40.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0610\/9229\/8829\/files\/IMG-1667_4796bc4c-b1d0-4b21-9110-74f7d7f3f28b.heic?v=1776097118","url":"https:\/\/whiskeyrebellionantiques.com\/products\/u-s-army-technical-manual-tm-11-2121-central-office-equipment-fundamentals-1950","provider":"Whiskey Rebellion Antiques","version":"1.0","type":"link"}