Update on rebuilding 15GP22's

[julianburke]

I updated my posting on "Moron alert on building 15G's but will post it here again:


UPDATE: One of the talks at the ETF was Bob Galanter (and John Folsom) giving their account of the two 15G's they tried to rebuild at Hawkeyes. Everyone was leaning on their chair to hear this one! It was very informative and promising. The main problem is the joining of the faceplate to the bell of the tube. Newer tubes use a frit which is a special glass epoxy to join the two pieces of glass which was not available at the time of the 15G production. RCA joined the two pieces of metal which were each annealed to the glass workpiece and apparently worked when manufactured but developed leaks along the last 50+ years. (actually 3--a ring washer of sorts in the center where they electrically welded them all together) It also poses the nightmare when trying to rebuild the tube as it leaks, leaks and leaks!