Today, the number of consumer level tube radios and televisions that are produced are slim to none. Although on the commercial, industrial or high end audio side, vacuum tubes are still being used for everything from radio station equipment, guitar amplifiers, stereo amplifiers and more.
With the introduction of the solid-state transistor, the vacuum tube was slowly phased out. This allowed manufacturers to produce TV’s and stereos that were smaller and cooler running. Our family had an old RCA console television, which used a multitude of vacuum tubes. We also had a large phonograph player/radio that used tubes as well.
My dad was a handy type of guy, so when our television would act up, he would take the rear panel off the TV, pull out the tubes and we would drive over to our neighborhood Thrifty Drug Store where he would test all the tubes he brought, to make sure they were ok. I remember the tube tester was sitting right by the front door as you walked in the store. It looked similar to the one pictured here.
The tester had a meter on it to indicate if the tube was good or bad. I remember there was a door under the tester portion and behind that door was a whole variety of brand new vacuum tubes in boxes, in all shapes and sizes. I guess you just matched the number on your old tube with the number on the new tube.
On this particular trip to the store, I’m not sure if the tubes that he brought in were good or bad, but I do remember seeing the neighborhood television repair man at our door not to long after.
On a side note–A few years ago, a friend of mine gave me this slick looking mini amplifier, that uses vacuum tubes of all things. The vacuum tubes are the two things just behind the Zvex logo that have a small orange glow emerging from them. This is the only electronic device I own that reminds me of those days of testing vacuum tubes at the neighborhood store with my dad. 
For more detailed information about the vacuum tube, visit wikipedia.com:
http://en.wikipedia.org/wiki/Vacuum_tube





