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.

It's worth deep diving into how analog composite broadcast television works, because you quickly realize just how insanely ambitious it was for 1930s engineers to have not only conceived, but perfected and shipped at consumer scale using only 1930s technologies.

Being old enough to have learned video engineering at the end of the analog days, it's kind of fun helping young engineers today wrap their brains around completely alien concepts, like "the image is never pixels" then "it's never digital" and "never quantized." Those who've been raised in a digital world learn to understand things from a fundamentally digital frame of reference. Even analog signals are often reasoned about as if their quantized form was their "true nature".

Interestingly, I suspect the converse would be equally true trying to explain digital television to a 1930s video engineer. They'd probably struggle similarly, always mentally remapping digital images to their "true" analog nature. The fundamental nature of their world was analog. Nothing was quantized. Even the idea "quanta" might be at the root of physics was newfangled, suspect and, even if true, of no practical use in engineering systems.

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.

Yes - and x-rays too! Both from the main TV tube itself (though often shielded) but historically the main problem was actually the vacuum rectifiers used to generate the high voltages required. Those vacuum tubes essentially became x-ray bulbs and had to be shielded. This problem appeared as the first color TV's appeared in the late 60s. Color required higher voltages for the same brightness, due to the introduction of a mask that absorbed a lot of the energy. As a famous example, certain GE TV's would emit a strong beam of x-rays, but it was downwards so it would mostly expose someone beneath the TV. Reportedly a few models could emit 50,000 mR/hr at 9 inches distance https://www.nytimes.com/1967/07/22/archives/owners-of-9000-c... which is actually quite a lot (enough for radiation sickness after a few hours). All were recalled of course!

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.

While not entirely thematically unrelated, being electric puts it distinctly outside of steampunk and even dieselpunk. I don't think anyone would call The Matrix steampunk but CRTs are at the center of its aesthetic. Cassette Futurism is the correct term I believe though it also overlaps with some sub-genres of cyberpunk.

This is a cool little project you might be interested in - https://github.com/mausimus/ShaderGlass

The shadow mask system for colour CRTs was a huge improvement that thwarted worries about ''beams everywhere'':

https://en.wikipedia.org/wiki/Shadow_mask

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.

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.

And perhaps peak atompunk too when used as RAM. [0]

[0] https://en.wikipedia.org/wiki/Williams_tube

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

'Steampunk' means no electricity. You need to come up with another term. Analogpunk, maybe?

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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