I remember seeing tube testers in stores in the early-mid 80s.
I remember getting the sticker kit. You put stickers on the tubes and the sockets in the TV. Take the tubes to the store and use the tester. Buy replacements for the bad tube. Put the tubes back in based on the stickers.The Supermarket had tubes for sale. I remember going w/my father. The first color tv we had was a Zenith. The remote used a chime to send sound to tv to change channel. GREAT shows to watch then.
I have to recommend this Youtube channel for anyone who likes watching old TVs being repaired:
https://www.youtube.com/user/shango066
I was also a tube runner. Speedy Mart down the street had a tube checking machine and a bunch of new ones in a display.Back in the late 60's my dad would send me to the local store to pick up tubes for the TV. He was a radio man during the Korean war, so he knew how to fix the TV.
It seemed our TVs were more prone to losing picture than sound.
I think the bank gave my folks a "portable" b&w tv for opening an account?
"Hey kids, what time is it?"