I have some old vacuum tubes, two type 71A, three type 27 and one type 80 which are each labeled Boro Radio Service and are dated July 30, 1938, They were given to me in 1958 and the idea that they were twenty years old at the time, older than I was then, made me think of them as being positively archaic. Today, those tubes are approaching their seventy-third birthday.
I don't know about the 71A or the 27 tubes, but I do know that the 80 works. The 80 is ancestral to the type 5Y3-GT rectifier, so I once adapted that 80 into the 5Y3-GT socket of a Heathkit AR-3 receiver. The radio worked.
Today, we are all familiar with the 2N2222 which is one of a family of NPN epitaxial planar transistors consisting of 2N2217, 2N2218, 2N2219, 2N2221 and of course the 2N2222 itself, not to mention the A-suffixed versions.
The first data sheet I ever saw for those transistors was printed in 1963. That data sheet was printed forty-eight years ago which means that the design life span of this specific transistor has now lasted far longer than what the design life span was for that vacuum tube.
We're always thinking and talking and reading about how quickly things change in this industry, but in fact, there are some things that really don't change all that quickly. There are at least some bastions of stability.
John, I can argue that the 80/5Y3 and a host of other tube types are still in production. Sadly, not very many are still made in the US, but none the less, they are still in production. I have a globe type 80 which is even older than your ST type 80 which is still in working order. The 6L6, introduced by RCA in 1936, is still in production as well. I have a 1939 dated 6L6G in my stock. Quite a few tubes are still being made and are still in frequent use. Many broadcast transmitters still use them (they are a much hardier breed than transistors, even if they are not as efficient), many HAMs still prefer tubes and of course there is the audio and guitar amplifier industry. Some audio recording studios still insist on tubes.
I can also agree that there are a fair number of transistors and ICs which have had a long production life and are still in production, however, there are far fewer discrete transistors available today than just a couple of decades ago (the 1980s were really bad for discrete parts) and a great many ICs have already become nearly impossible to find in only a decade or so. Just check out the obsolete market for pricing, that'll make your heart skip a few beats!
I think we're in much too much a hurry to drop 'older' parts for what are supposed to be better and improved (sometimes they really are) components. They hobbist market has been all but killed by 'advancements' such as SMT and high integration and it has certainly put a dent in some small design houses business by making it harder and more expensive to produce prototypes.
Posted by: Edwin | May 29, 2011 at 03:16 PM
Your tube lineup sounds like that of an early AC-operated TRF (tuned radio frequency) type radio, from about 1928-30. The type 80 tube was introduced in 1927, so the lifetime of this bottle is very long indeed. The Tube Collectors Association could tell you much more about it; president Ludwell Sibley has a book, "Tube Lore", which is considered the definitive tome on early vacuum tubes.
Posted by: Mark Nelson | June 01, 2011 at 09:00 AM
Hi, Mark.
You are correct. Upon some reflection however, the year I got them was actually 1956 rather than 1958.
A friend of mine who was then living in the next aparement building gave it to me and I had it in my room for several years until my father made me throw it out. I saved only the tubes of which the line-up was one type 80, two type 71A and five type 27. Some years later, I accidentally broke two of the type 27 tubes when I dropped them.
More recently however, I saw another one of the same radio on display in the building lobby of Modular Devices, all nice and clean and quite a treasure! It had a full set of tubes of course.
John
Posted by: John Dunn | June 01, 2011 at 09:34 AM
John, you might find this website useful-----It covers the first 100 tube numbers that finally died out when the Octal base was introduced.
http://www.vacuumtubesinc.com/TubeTidbits/TwoDigitTypesFrom1to100.aspx
Copy this into your browser and it should open up. I find this
info fascinating since I was a kid that fixed old radios during
WW2 by using parts from discarded radios to repair what I could.
So I was very familiar tubes used in the late '20s into the mid to late '30s.
Carl Schwab
Posted by: Carl Schwab | June 01, 2011 at 01:09 PM