Designing For The Small Grey Screen

May 3, 2022 by Jenny List 23 Comments

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?

April 16, 2022 by Jenny List 23 Comments

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

April 10, 2022 by Dan Maloney 21 Comments

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.

Old Portable TV Becomes Unique CRT Cyberdeck

February 28, 2022 by Dan Maloney 10 Comments

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.

Continue reading “Old Portable TV Becomes Unique CRT Cyberdeck” →

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

February 23, 2022 by Lewin Day 28 Comments

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.

Continue reading “Pulling Off A CRT Transplant Doesn’t Have To Be Tricky!” →

Tiny TV Celebrates The Forgotten Tech Of CRTs

February 11, 2022 by Dan Maloney 35 Comments

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.

Modern Features In Classic Radio

December 7, 2021 by Bryan Cockfield 53 Comments

As consumer electronics companies chase profits on tighter and tighter margins, it seems like quality is continually harder to find for most average consumer-grade products. Luckily, we don’t have to hunt through product reviews to find well-built merchandise since we have the benefit of survivorship bias to help us identify quality products from the past that have already withstood the test of time. [Tom] has forever been fond of this particular Sony TV/radio combo from the ’70s so he finally found one and set about modernizing it in a few key ways.

Among the modifications to this 1978 Sony FX-300 include the addition of a modern color display, Bluetooth, an upgraded FM radio, and a microphone. At the center of all of this new hardware is a Teensy 4 which [Tom] has found to be quite powerful and has enough capabilities to process the audio that’s being played in order to make visual representations of the sound on the screen. He also implemented a bitcrusher filter and integrated it into the controls on the original hardware. He’s using an optimized version of this library to cram all of that processing ability into such a small chip, and the integration of all this new hardware is so polished that it looks like it could be an original Sony stereo from the modern era.

While some may complain about restomod-type builds like this, we don’t really see any need to be arbitrarily or absolutely faithful to bygone eras even if the original hardware was working properly in the first place. What works is taking the proven technology of the past and augmenting it with modern features to enjoy the best of both worlds. Much like this hi-fi stereo which blends the styles and technology of the 90s with that of the 60s in an equally impressive way.