At one time in my life, my father owned a company called Television Tube Testing. He placed tube testers in grocery stores. There were rolls of numbered stickers with the numbers in pairs in a bin. The instructions told the customers to take a roll home with them. After turning off the set, un plugging it, and waiting a specified time to allow any high voltage to discharge, the customers were instructed to remove all the tubes, other than the picture tube, on at a time. When each tube was removed they were told to place one sticker on the socket, and the other sticker with the same number on the tube, being careful not to cover up the manufacturer's name and model number. The customer would then return to the store, look up each tube in a book which listed which socket it should be plugged in and how to set 2 selector knobs. Then push a button, a red light would indicate failure and a green light pass. The customer would then select replacements from a stock of tubes, buy them at the checkout, and take them home to repair the set.
Before my parents bought our very first color set in the early 70's, my brother and I were obsessed with getting color out of a B/W TV. There were a series of articles, I forget the publication (maybe Popular Science?) that discussed a device with a vertical flat rectangular semi-transparent frame that could be placed in front of a small (9") B/W TV and yield a color picture. It differed from the synchronized spinning color wheel ideas of the time by instead employing a transparent tri-colored sheet stretched between two synchronized rollers at the top and bottom of the frame. I won't go into details here but the reviewers claimed that the picture was a bit dim but quite watchable. Noted was the fact that the picture was sharp and free of convergence issues which plagued color sets of the time.
When we finally went out to buy that color set, my dad splurged and bought a Motorola 21-inch "works in a drawer" set with remote control. It had the best picture of any of the TVs in the store, well worth the (dear) $475 he paid for it. I remember getting it home and finally watching all my favorite shows in glorious color. There was an indescribable feeing to that, like I had developed a new sense.
I was completely unimpressed. We were visiting friends and the "man of the house" was excitedly demonstrating their new color TV. He turned a knob one way and the picture was all purple. Then he turned it the opposite way and everything was green. Finally, he settled on "purplish". Big deal, I thought, I could do that with pieces of colored plastic for much less money.
When the kids were young and were looking at old photos, I used to tell them that colors hadn't been invented yet and that trees were really gray. They bought it for a while....
@ "One of my favorite tasks was to take the tubes out of the set and bring them to our local electronics store to be checked. "
Every corner drug store (pharmacy) had a do-it-yourself tube tester and stocked the common radio and TV tubes. You would look up the tube type on a roll chart which listed the proper socket and knob settings, plug in the tube and wait 30 seconds. If there was a heater to cathode short a neon lamp would light up. Pushing the test button swung a meter into either red bad or green good zone, with a thin wedge of yellow ? in the middle. It was just a basic go/nogo emission test, but enough to get your TV back up if a tube failed on a Sunday.
NTSC was a remarkable technique that did not make pre-existing black and white TV sets obsolete. It took a lot of thought and experimentation. But still it sometimes was referred to as "Never Twice Same Colour"
Thanks for the kind words re my blogs -- I just learned something from you, because I didn't realize color TV transmission didn't start in India until 1982... like I say, all of this really isn't so long ago when you come to think about it...
What are the engineering and design challenges in creating successful IoT devices? These devices are usually small, resource-constrained electronics designed to sense, collect, send, and/or interpret data. Some of the devices need to be smart enough to act upon data in real time, 24/7. Specifically the guests will discuss sensors, security, and lessons from IoT deployments.