Yep, tube radios... Had to let the tubes warm up.
And tube TVs. Heading down to the local Radio Shack or something similar to use their tube tester to find out what to replace to get the TV working.
When I was in grad school in the late 80s, there was a table in the lounge area where people would put unwanted things when they moved out of an office. One day, a nice tabletop cabinet radio (tube type) showed up there. I went by later and it was plugged in and playing; it sounded good, so I took it home (still have it). I’m sure that some kid plugged it in, turned it on, decided it didn’t work, and wandered off.
And the tv had to warm up.
Remember the 4 foot tall tube radios?
The B&W TV went out and Dad and I would make a “map” of the tubes location on the TV Circuit Board then taking out the ones We thought were bad and then We would go to the Drugstore or Hardware Store and use the Tube Tester and then buy replacement tube(s) for the bad ones, take them home and put the TV back together and Pray it worked.
Now all those tubes are crammed into a chip the size of a Dime.