Retrotechtacular: How Television Worked In The 1950s

Watching television today is a very different experience from that which our parents would have had at our age, where we have high-definition digital on-demand streaming services they had a small number of analogue channels serving linear scheduled broadcasting. A particular film coming on TV could be a major event that it was not uncommon for most of the population to have shared, and such simple things as a coffee advert could become part of our common cultural experience. Behind it all was a minor miracle of synchronised analogue technology taking the signal from studio to living room, and this is the subject of a 1952 Coronet film, Television: How It Works!  Sit back and enjoy a trip into a much simpler world in the video below the break.

Filming a TV advert: 1950s housewife sells cooker
Production values for adverts had yet to reach their zenith in the 1950s.

After an introduction showing the cultural impact of TV in early-50s America there’s a basic intro to a cathode-ray tube, followed by something that may be less familiar to many readers, the Image Orthicon camera tube that formed the basis of most TV signals of that era.

It’s written for the general public, so the scanning raster of a TV image is introduced through the back-and-forth of reading a book, and then translated into how the raster is painted on the screen with the deflection coils and the electron gun. It’s not overly simplified though, for it talks about how the picture is interlaced and shows how a synchronisation pulse is introduced to keep all parts of the system working together.

A particularly fascinating glimpse comes in a brief mention of the solid copper co-axial cable and overland microwave links used to transmit TV signals across country, these concrete towers can still be seen today but they no longer have the colossal horn antennas we can see in the film.

A rather obvious omission in this film is the lack of any mention of colour TV, as while it would be late 1953 before the NTSC standard was formally adopted and early 1954 before the first few colour sets would go on sale. Colour TV would have been very much the Next Big Thing in 1952, but with no transmissions to watch and a bitter standards war still raging between the field-sequential CBS system and RCA’s compatible dot-sequential system that would eventually evolve into the NTSC standard  it’s not surprising that colour TV was beyond the consumer audience of the time.

Thus we’re being introduced to the 525-line standard which many think of as NTSC video, but without the NTSC compatible colour system that most of us will be familiar with. The 525-line analogue standard might have disappeared from our living rooms some time ago, but as the last few stations only came off-air last year we’d say it had a pretty good run.

We like analogue TV a lot here at Hackaday, and this certainly isn’t the first time we’ve gone all 525-line. Meanwhile for a really deep dive into the inner workings of TV signal timing, get ready to know your video waveform.

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Designing For The Small Grey Screen

With the huge popularity of retrocomputing and of cyberdecks, we have seen a variety of projects that use a modern computer such as a Raspberry Pi bathed in the glorious glow of a CRT being used as a monitor. The right aesthetic is easily achieved this way, but there’s more to using a CRT display than simply thinking about its resolution. Particularly a black-and-white CRT or a vintage TV has some limitations due to its operation, that call for attention to the design of what is displayed upon it. [Jordan “Ploogle” Carroll] has taken a look at this subject, using a 1975 Zenith portable TV as an example.

The first difference between a flat panel and a CRT is that except in a few cases it has a curved surface and corners, and the edges of the scanned area protrude outside the edges of the screen. Thus the usable display area is less than the total display area, meaning that the action has to be concentrated away from the edges. Then there is the effect of a monochrome display on colour choice, in other words the luminance contrast between adjacent colours must be considered alongside the colour contrast. And finally there’s the restricted bandwidth of a CRT display, particularly when it fed via an RF antenna socket, which affects how much detail it can reasonably convey. The examples used are games, and it’s noticeable how Nintendo’s design language works well with this display. We can’t imagine Nintendo games being tested on black-and-white TV sets in 2022, so perhaps this is indicative of attention paid to design for accessibility.

While they require a bit of respect due to the presence of dangerous voltages, there’s a lot of fun to be had bringing a CRT into 2022. Get one while you still can, and maybe you could have a go at a retro cyberdeck.

Can You Help Solve The Mystery Of This 1930s TV?

84 years ago, a teenager built a TV set in a basement in Hammond, Indiana. The teen was a radio amateur, [John Anderson W9YEI], and since it was the late 1930s the set was a unique build — one of very few in existence built to catch one of the first experimental TV transmitters on air at the time, W9XZV in Chicago. We know about it because of its mention in a 1973 talk radio show, and because that gave a tantalizing description it’s caught the interest of [Bill Meara, N2CQR]. He’s tracking down whatever details he can find through a series of blog posts, and though he’s found a lot of fascinating stuff about early TV sets he’s making a plea for more. Any TV set in the late ’30s was worthy of note, so is there anyone else out there who has a story about this one?

The set itself was described as an aluminium chassis with a tiny 1″ CRT, something which for a 1930s experimenter would have been an expensive and exotic part. He’s found details of a contemporary set published in a magazine, and looking at its circuit diagram we were immediately struck by how relatively simple the circuit of an electrostatically-deflected TV is. Its tuned radio frequency (TRF) radio front end is definitely archaic, but something that probably made some sense in 1939 when there was only a single channel to be received. We hope that [Bill] manages to turn up more information.

We’ve covered some early TV work here not so long ago, but if you fancy a go yourself it’s not yet too late to join the party.

Retrotechtacular: A DIY Television For Very Early Adopters

By our very nature, hackers tend to get on the bandwagon of new technology pretty quickly. When something gee-whiz comes along, it’s folks like us who try it out, even if that means climbing steep learning curves or putting together odd bits of technology rather than waiting for the slicker products that will come out if the new thing takes off. But building your own television receiver in 1933 was probably pushing the envelope for even the earliest of adopters.

“Cathode Ray Television,” reprinted by the Antique Valve Museum in all its Web 1.0 glory, originally appeared in the May 27, 1933 edition of Popular Wireless magazine, and was authored by one K D Rogers of that august publication’s Research Department. They apparently took things quite seriously over there at the time, at least judging by the white lab coats and smoking materials; nothing said serious research in the 1930s quite like a pipe. The flowery language and endless superlatives that abound in the text are a giveaway, too; it’s hard to read without affecting a mental British accent, or at least your best attempt at a Transatlantic accent.

In any event, the article does a good job showing just what was involved in building a “vision radio receiver” and its supporting circuitry back in the day. K D Rogers goes into great detail explaining how an “oscillograph” CRT can be employed to display moving pictures, and how his proposed electronic system is vastly superior to the mechanical scanning systems that were being toyed with at the time. The build itself, vacuum tube-based though it was, went through the same sort of breadboarding process we still use today, progressing to a finished product in a nice wood cabinet, the plans for which are included.

It must have been quite a thrill for electronics experimenters back then to be working on something like television at a time when radio was only just getting to full market penetration. It’s a bit of a puzzle what these tinkerers would have tuned into with their DIY sets, though — the airwaves weren’t exactly overflowing with TV broadcasts in 1933. But still, someone had to go first, and so we tip our hats to the early adopters who figured things out for the rest of us.

Thanks to [BT] for the tip.

 

CRT cyberdeck

Old Portable TV Becomes Unique CRT Cyberdeck

Remember the “suitcase” form-factor for PCs? In the time before latops, these luggable machines were just the thing for the on-the-go executive. OK, maybe not really — but the ability to have PC, monitor, and peripherals in a single package had real appeal, and a lot of that rationale is behind the cyberdeck phenomenon. So when we saw this retro portable TV turned into a cyberdeck, it really caught our eye.

Ironically, the portable black-and-white TV that [Lucas Dul] chose as the basis for his cyberdeck hails from about the same period in time that luggable PCs were having their brief time in the sun. Scored from eBay, the Magnavox TV/radio combo had seen better days, and required a bit of surgery to repair what might have been drop damage. With the CRT restored and the video and audio paths located, the TV got a Raspberry Pi, a small touchpad, and a couple of concealed USB connectors. The Pi’s composite output drives the CRT, with about the results you’d expect. The keyboard appears to be just about the right size to serve as a cover, but [Lucas] said that’s a future project.

Still, with the TV’s original handle acting as a stand, this cyberdeck gives off a real Compaq or IBM portable PC vibe. We’ve seen a few luggable-lookalike cyberdecks before, but none that dared use a CRT monitor. It may be a far cry from HDMI, but we really appreciate that [Lucas] chose this way rather than slapping in an LCD.

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Pulling Off A CRT Transplant Doesn’t Have To Be Tricky!

Whether it’s an engine swap in an old car or pulling a hard drive out of an old computer, we often find ourselves transplanting bits from one piece of hardware to another. [Emily Velasco] recently attempted this with a pair of CRTs, and came away with great success.

The donor was an old 1980s fishing sounder, which came complete with a rather fetching monochrome amber CRT display. [Emily]’s goal was to transplant this into the body of a early 2000s portable television. The displays were of a similar size and shape, though the Toshiba CRT from the 80s used a lot more glass in its construction.

The tube socket in the TV used to hook up the display matched the old CRT perfectly, so there were no hassles there. A bit of soldering was all that was needed to hook up the yoke, and [Emily] was ready to test. Amazingly, it powered up cleanly, displaying rolling amber static as you’d expect, given that analog television stations have been off the air for some time now.

After some perseverance, a VCR playing Mystic Pizza on VHS was able to deliver a video signal to the TV, proving that everything was working well. The next stage of the project is to get the television electronics to fit inside the 1980s fishing sounder housing, as it’s the more attractive of the two. Things were just built differently back in those days!

We’ve seen some other great vintage display swaps before, too. Video after the break.

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Tiny TV Celebrates The Forgotten Tech Of CRTs

For those of us who grew up before the Internet, the center of pretty much every house was the TV. It was the shrine before which we all worshipped, gathering together at the appointed times to receive the shared wisdom of mass entertainment. In retrospect, it really wasn’t that much. But it’s what we had.

Content aside, one thing all these glowing boxes had in common was that which did the glowing — the cathode ray tube (CRT). Celebrating the marvel of engineering that the CRT represents is the idea behind [Matt Evan]’s tiny desktop TV. The design centers around a 1.5″ CRT that once served as a viewfinder on a 1980s-vintage Sony camcorder. [Matt] salvaged the tube and the two PCB assemblies that drive it, mounting everything in a custom-built acrylic case, the better to show off the bulky but beautiful tube.

The viewfinder originally used a mirror to make the optical path more compact; this forced [Matt] to adapt the circuit to un-reverse the image for direct viewing. Rather than receiving analog signals off the air as we did in the old days — and we liked it that way! — the mini monitor gets its video from a Raspberry Pi, which is set to play clips of TV shows from [Matt]’s youth. Rendered in glorious black and white and nearly needing a magnifying glass to see, it almost recaptures the very earliest days of television broadcasting, when TVs all had screens that looked more like oscilloscope CRTs.

This project is a nice homage to a dying technology, and [Matt] says it has spurred more than one conversation from people you grew up knowing only LCD displays. That’s not to say CRTs are totally dead — if you want to build your own old-school TV, there’s a kit for that.