Wow, I need to tell my daughters about vacuum tubes tomorrow. (They can correctly identify typewriters) I remember as a kid my father would fix the B&W TV and he would take vacuum tubes from the TV that were going dim and testing them at a local store and replacing the bad ones. I guess this was before the days of Radio Shack.
My father decided to retire from DOD electronics work when vacuum tubes became obsolete, but his son works online and his grandson is a transportation planner going all digital