alt Hacker NewsCRTs are peak steam punk technology. Analog, electric, kinda dangerous. Just totally mindblowing that we had these things in our living rooms shooting electric beams everywhere. I doubt it's environmentally friendly at all, but I'd love to see some new CRTs being made.
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There's a synchronous and instantaneous nature you don't find in modern designs.
The image is not stored at any point. The receiver and the transmitter are part of the same electric circuit in a certain sense. It's a virtual circuit but the entire thing - transmitter and receiving unit alike - are oscillating in unison driven by a single clock.
The image is never entirely realized as a complete thing, either. While slow phosphor tubes do display a static image, most CRT systems used extremely fast phosphors; they release the majority of the light within a millisecond of the beam hitting them. If you take a really fast exposure of a CRT display (say 1/100,000th of a second) you don't see the whole image on the photograph - only the most recently few drawn lines glow. The image as a whole never exists at the same time. It exists only in the persistence of vision.
I was on a course at Sony in San Mateo in the 1980s and they had a 36" prototype television in the corner. We all asked for it to be turned on. We were told by the instructor that he was not allowed to turn it on because the 40,000V anode voltage generated too many X-rays at the front of the picture tube.
:-))))
One summer odd-job included an afternoon of throwing a few dozen CRTs off a 3rd floor balcony into a rolloff dumpster. I'da done it for free.
What do you mean "had"? I just turned mine off a minute ago. I am yet to make the transition to flat screen TVs but in the mean time, at least no-one's tracking my consumer habits.
Extra dangerous aspect: On really early CRTs they hadn't quite nailed the glass thicknesses. One failure mode was that the neck that held the electron gun would fail. This would propell the gun through the front of the screen, possibly toward the viewer.
The shadow mask system for colour CRTs was a huge improvement that thwarted worries about ''beams everywhere'':
With CRTs, the environmental problem is the heavy metals: tons of lead in the glass screen, plus cadmium and whatnot. Supposedly there can be many pounds of lead in a large CRT.
This thread makes me realise that the old Telequipment D61 Cathode Ray Oscilloscope I have is worth hanging on to. It's basically a CRT with signal conditioning on its inputs, including a "Z mod" input, making it easy to do cool stuff with it.
We're getting awfully close to recreating CRT qualities with modern display panels. A curved 4:3 1000Hz OLED panel behind glass, and an integrated RetroTink 4K with G-Sync Pulsar support would do it. Then add in a simulated degauss effect and electrical whine and buzzing sounds for fun.
The 1940-1990 era of technology can't be beat. Add hard drives and tape to the mix. What happened to electromechanical design? I doubt it would be taught anymore. Everything is solid state
Also, I believe precursors to CRT existed in the 19th century. What was unique with television was the creation of a full CRT system that allowed moving picture consumption to be a mass phenomena.
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That and modern digital TV is just incredibly boring from the technical standpoint. Because everything is a computer these days, it's just some MPEG-2 video. The only thing impressive about it is that they managed to squeeze multiple channels worth of video streams into the bandwidth of one analog channel.