[Hammarlund] speaking of tubes

[Mike Durff]

I read, many years ago, that entities line Western Electric and the military kept track of the numbers of tube sockets for tube XXX. This was done to calculate future demand.  In the case of W.E. the now revered 300 series of triode was made from the mid 1930's until the WE Kansas city plant closed in the 1980's ( AFAIK ).  When I toured the old Ken-Rad/GE/MPD plant in Kentucky in the early 1990's, I was given a "commemorative" 6550. They were the last to come off that line. I was told the military used them by the thousands at one time. 
But, I would agree... in my lifetime (I'm 64 ) I've seen more 12AX? and 6L6 than anything else, by far. They are in almost every electric guitar amplifier ever made. Those figures may come close to military use as they are still being produced to this day. 
TNX, Mike, K4TQF

PS: The 6550 I have was hand made, just as they always had been,  mostly by women. One of the rooms I saw held all the dies for the different shapes of plates, etc. The only really "automated" process was the operation of the 22 "Sealex" machines that evacuated the tube & sealed the stem. Richardson Electronics had purchased the Sealex machines and ordered them destroyed. I think one was to be shipped to Richardson in the Chicago area.