{"product_id":"ww2-admiralty-transmitting-triode-valve-thermionic-tube-cv1222-nt39-at75","title":"WW2 Admiralty Transmitting Triode Valve\/Thermionic Tube CV1222\/NT39\/AT75","description":"\u003ch1 class=\"normal break-word mb-xs-2\" data-buy-box-listing-title=\"\" data-listing-id=\"707618710\"\u003eWW2 Admiralty Transmitting Triode Valve\/Thermionic Tube CV1222\/NT39\/AT75\u003c\/h1\u003e\n\u003cp\u003eThis is a little piece of Radio Communication history in the form of a British ,Air Cooled, WW2 Admiralty Transmitting Triode Valve\/Thermionic Tube CV1222\/NT39\/AT75. They were manufactured from the 1920s to the 1940s.\u003c\/p\u003e\n\u003cp\u003eIt has a large 4-pin bayonet base and external anode with integral finned radiator. The valve was suitable as an amplifier or oscillator down to 10 metres at full rating and down to 4 metres at reduced HT voltage. Marconi were thought to have used this type of valve in their transmitters.\u003c\/p\u003e\n\u003cp\u003eA nice looking gadget for display in the vintage office, the filament is actually showing continuity; a sign that the valve is probably working!\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eApproximate Dimensions\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eHeight: 21.5cm\u003cbr\u003eDiameter Base: 4.8cm\u003c\/p\u003e\n\u003cp\u003eThe triode is very faintly stencilled with:\u003c\/p\u003e\n\u003cblockquote\u003e\n\u003cp\u003eADMIRALTY\u003c\/p\u003e\n\u003cp\u003e813\u003c\/p\u003e\n\u003cp\u003eNT39\u003c\/p\u003e\n\u003cp\u003eand the air ministry arrow\u003c\/p\u003e\n\u003cp\u003ealso: 5433C\u003c\/p\u003e\n\u003c\/blockquote\u003e\n\u003cp\u003e\u003cstrong\u003eSpecification- see image\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eFilament: 10 V – 1.65 A\u003cbr\u003eMax. anode voltage: 1500 V\u003cbr\u003eMax. anode dissipation: 75 W\u003cbr\u003eAmplification factor: 22\u003cbr\u003eMutual conductance: 5.0 mA\/V\u003cbr\u003eAnode impedance: 4200 ohms\u003cbr\u003eMax frequency for 75% anode rating: 37 MHz\u003c\/p\u003e\nPlease click on the following links for more \u003ca href=\"https:\/\/mullardantiques.co.uk\/collections\/radio-equipment-accessories\" target=\"_blank\" rel=\"noopener noreferrer\"\u003eradio communication accessories\u003c\/a\u003e or \u003ca href=\"https:\/\/mullardantiques.co.uk\/collections\/militaria\" target=\"_blank\" rel=\"noopener noreferrer\"\u003emilitaria.\u003c\/a\u003e\u003cstrong\u003e\u003c\/strong\u003e","brand":"Admiralty","offers":[{"title":"Default Title","offer_id":37199773859989,"sku":"","price":0.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0303\/5122\/8972\/products\/DSC04192_80b68ad0-2772-45fe-8412-ca13448facf6.jpg?v=1604842762","url":"https:\/\/mullardantiques.co.uk\/en-us\/products\/ww2-admiralty-transmitting-triode-valve-thermionic-tube-cv1222-nt39-at75","provider":"Mullard Antiques and Collectibles","version":"1.0","type":"link"}