AND I mean old ; pre T.V. When a radio sat on the floor and was about 5' tall. If the bloody thing stopped; you ripped off the back and grabbed any valve that was not lit up; go to the shop; get new valve, plug it in, problem solved, The days before some lunatic came around to look at your computer and charged you $100. GEE, I sure miss those days before techs got to know all about you. I mean all those secret "little" things.