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Old 8th Dec 2006, 8:16 pm   #4
Steve_McVoy
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Join Date: Feb 2004
Location: Columbus, Ohio, USA
Posts: 150
Default Re: Pre war CRT photo

In the 1980s a U.S. company successfully rebuilt a 9AP4 using the graded glass approach.

A company in the U.S. recently spent a great deal of effort trying to rebuild a 12AP4 (Pyrex) tube. They found glass for the tubing, but gave up when they couldn't find a stem that had characteristics close enough to the Pyrex. A custom stem would cost several thousand dollars in tooling cost, and a large minimum order.

For now, the prospects of rebuilding this type of tube is bleak. We are still exploring other options, though.
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