Pete,
I don't know if the effect you are talking about is limited to tubes.We have gone from an economy where the goal used to be to build things as well as we could to a throw away economy where the thought not how well can I make this but rather how cheaply can I make this before people will stop buying it. We have gone from having pride in a quality product to looking nowhere further than this quarters earnings report.
Besides that Vintage Western Electric products have always been in a league of their own. Lets remember that most all Western Electric were never sold to the general public. Western Electrics main reason for being was to be the equipment supplier for the Bell System. With very few exceptions, everything they manufactured was for internal consumption by AT&T's operating telephone company's. When something broke, they were the ones tat had to buy another one. And the Bell System standards had no tolerance for system failures (The standard for availability for telephone switches was no more than 60 seconds of down time every 20 years!) Given these two things it is no wonder that the WE QC/QA were so crazy. Also keep in mind that during this time the telephone industry operated as a regulatory utility with cost plus pricing standards so there was no need to cut corners on what they spent on building the network.
So it is was kind of a double whammy. product quality was a much higher priority back then, but WE just took it to a level that even back then was unheard of in outside industry (with the exception of maybe mil spec products.
I'm not sure that the secrets of tube manufacturing have disappeared as much as the desire to manufacture first rate tubes (or rather willingness to pay for what it would take to make them as good as they were in the old days.)
Tom
