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Tube Shelf Life

I have purchased several NIB Electroharmonix tubes. These are the new variety and not NOS. Does anyone know what the anticipated shelf life is on these newer tubes or any reason to believe that they will degass or otherwise degrade faster than NOS from 20 or more years ago?
nanderson

Showing 2 responses by eldartford

eldartford
4,262 posts
 
Ed_sawyer...A military equipment that I was involved with had a vidicon tube, and to maintain its life we had a requirement to turn on and operate spare units for 30 minutes every 90 days. This was to get the getter hot. I guess there may be different kinds of getter.

Early vintage TV tubes (CRTs) definitely had problems if stored for a year or more without operation. Of course, a CRT has a lot of glass area for leakage to occur.
eldartford
4,262 posts
 
Quincy...As you say, vacuum tubes generally include a "getter" to "get" stray atoms of gas that leak into the tube. However, I think that the getter needs to be hot to do its job, which means that the tube should be operated. Early vintage CRT tubes used to fail easily due to gas. A TV that was stored unused for a year or more usually meant a ruined tube. Recent vintage TVs don't seem to have this problem.
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