Some files have compressed images that may not work correctly with older versions of Acrobat reader.Excellent triode curves for the 813 from Frens Mazenier (3.9MB GIF file) Excellent triode curves for the 814 from Frens Mazenier (3.9MB GIF file) Triode curves for the 814 (XLS file) (PDF file) Triode curves for the PT15 (XLS file) (PDF file) Triode curves for the 829B - Thanks to Paul Le Clercq - Tube #1 (XLS) (PDF), tube #2 (XLS) (PDF) Triode curves for the 12GN7A - Thanks to John Atwood - GE, RCA, Sylvania Jeff Duntemann's pages on Compactron tubes and low-voltage tubes 1958 Amperex tubes catalog, with short data (743k B PDF file) 1959 Electron Tubes and Semiconductors short-form data (16MB PDF file) 1963 Electron Tubes short-form data (9MB PDF file) 1956 Hi-Fi and Audio Tubes short-form data (7MB PDF file) "Five-Star Tubes" (PDF, 2MB) - Describes GE's high-reliability tubes, their construction, testing, etc. "GE Essential Characteristics", the whole 228 page book in an indexed PDF file (BIG, 11MB!
Includes most of Tung-Sol's tubes made between the 1930s up to 1948.includes the old 2-digit tubes, octals, loctals, and 7- and 9-pin-miniature tubes. ) since the last I wrote a report on the vacuum tube industry.I made some mistakes back then, that now when I look back I notice. Since I wrote my last report, the vacuum tube market has shifted especially in China and the high end hifi segment of the market.Current audio vacuum tube production is still largely limited to 3 locations: China, Russia and the Czech and Slovak Republics.
While many other developed nations still produce and develop vacuum based electronics, only Japan and Germany have produced glass vacuum tubes suitable for audio recently.
Month=third and fifth digits=08=August Year=fourth digit is the year, 8=1968. Genuine Telefunken Germany (Berlin and Ulm) made tubes have a diamond mark molded into the glass between the pins.
If the diamond mark is missing, the tube was likely made by Siemens or another of the Dutch Philips companies.
In the seven years since their launch, the Shuguang Treasure tubes have dropped by about 50% in price.
Psvane high end tube have also dropped and cost just slightly more.
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