return

Messing up &
Sizes of vacuum tubes in archaic computers

Comments by Ed Thelen Messing Up, a tale from the past Another techie nearby had a plaque hanging over his work bench. Many names were on the plaque, including the name of the lab manager. I asked my fellow techie what outstanding thing he had done to have the plaque hanging over his bench, with his name on the list. He looked at me sideways and said that was a circulating Boo-Boo award. He had screwed up at least $50 worth of equipment, and he would be happy if I did the same so the plaque would be hung above my bench instead of his. (At that time, the high class engineers up-stairs were making $5/hr.) And sizes of vacuum tubes in archaic computers Some vacuum tubes were "full size", such as these in the early core memory      http://ed-thelen.org/comp-hist/PaulPierce-709-.jpg - unit on left from      http://ed-thelen.org/comp-hist/CHM-Warehouse-2014.html Typical size and ratings      https://www.jj-electronic.com/en/6l6gc-7027-a      max length 115 mm, about 4.5 inches Mostly they were "miniature", yielding an output power of less than say 2 watts.      such as in this http://ed-thelen.org/comp-hist/IBM709-tubes-.jpg These were popular as amplifying logic switches      https://www.jj-electronic.com/en/ecc82-12au7-gold      max length 56 mm, a shade over 2 inches      Just the cathode heaters of these little guys give off 1.9 watts, that is with zero plate current !! The only 2 vacuum tubes in a 1401 system      (hidden in the timing alignment circuit to drive neon lamps) are in the 1402 . These are "miniature".     (Even smaller vacuum tubes were developed in WWII,      for proximity fuses and "ultra high" frequency - say 120 MHz purposes.)