A TV With Contrast You Haven’t Seen For Years

It’s something of a surprise, should you own a CRT TV to go with your retrocomputers, when you use it to view a film or a TV show. The resolution may be old-fashioned, but the colors jump out at you, in a way you’d forgotten CRTs could do. You’re seeing black levels that LCD screens can’t match, and which you’ll only find comparable on a modern OLED TVs. Can an LCD screen achieve decent black levels? [DIY Perks] is here with a modified screen that does just that.

LCD screens work by placing a set of electronic polarizing filters in front of a bright light. Bright pixels let through the light, while black pixels, well, they do their best, but a bit of light gets through. As a result, they have washed-out blacks, and their images aren’t as crisp and high contrast as they should be. More modern LCDs use an array of LEDs as the backlight which they illuminate as a low resolution version of the image, an approach which improves matters but leaves a “halo” round bright spots.

The TV in the video below the break is an older LCD set, from which he removes the backlight and places the electronics in a stand. He can show an image on it by placing a lamp behind it, but he does something much cleverer. An old DLP projector with its color wheel removed projects a high-res luminance map onto the back of the screen, resulting in the coveted high contrast image. The final result uses a somewhat unwieldy mirror arrangement to shorten the distance for the projector, but we love this hack. It’s not the first backlight hack we’ve seen, but perhaps it give the best result.

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Is This The Oldest HD Video Online?

Take a look at this video from [Reely Interesting], showing scenes from traditional Japanese festivals. It’s well filmed, and as with any HD video, you can see real detail. But as you watch, you may see something a little out of the ordinary. It’s got noise, a little bit of distortion, and looking closely at the surroundings, it’s clearly from the 1980s. Something doesn’t add up, as surely we’d expect a video like this to be shot in glorious 525 line NTSC. In fact, what we’re seeing is a very rare demo reel from 1985, and it’s showing off the first commercial HDTV system. This is analogue video in 1035i, and its background as listed below the video makes for a very interesting story.

Most of us think of HDTV arriving some time in the 2000s when Blu-ray and digital broadcasting supplanted the NTSC or PAL systems. But in fact the Japanese companies had been experimenting since the 1960s, and these recordings are their first fruits. It’s been digitized from a very rare still-working Sony HDV-1000 reel-to-reel video recorder, and is thus possibly the oldest HD video viewable online. They’re looking for any HDV-1000 parts, should you happen to have one lying around. Meanwhile, the tape represents a fascinating window into a broadcast history very few of us had a chance to see back in the day.

This isn’t the first time we’ve touched on vintage reel-to-reel video.

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Bringing A Current Dumping Amplifier Back To Life

Over the years there have been many different audio amplifier designs which have found favour for a while and then been supplanted by newer ideas. One of them has crossed the bench of [Jazzy Jane], it’s a current dumping amplifier from the mid-1980s. A nicely-done home-made project on stripboard mounted on a wooden base board, it sports a power supply, RIAA pre-amp board, and the amplifier itself.

The current dumping amplifier is one that combines a small class A amplifier with a hefty class B one, and through feedback trickery uses the combination to remove the crossover distortion of the class B stage. It’s a simple yet elegant circuit with fewer parts than an equivalent class AB amplifier, and there was a time back in the day when it was all the rage. This one has an op-amp providing the class A part and a complimentary pair of Darlington pairs as the class B.

The video below the break shows the process of bringing the amp back to life, a process mostly concerned with the power supply. There are a set of tantalum capacitors which have failed, and the replacements she’s using turn out to have problems too. They’re a period part for a project of this age, but we might have been tempted to go for another capacitor type here.

The result is an unusual amplifier, brought back to life. You may have seen [Jane] feature here before, with her 1950s signal generator.

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Jeff Dunham next to a Philco Predicta TV

Jeff Dunham Finds A NOS 1958 Philco Predicta

When you see a ventriloquist like [Jeff Dunham], you probably expect to see him with a puppet. This time – spoilers ahead – you won’t. Besides his fame on stage, [Dunham] is also a collector of vintage tech and a die-hard television enthusiast. In the video below, [Dunham] has gotten his hands on a rarity: an unboxed 1958 Philco Predicta TV. The original tape was still on the box. We get to follow along on his adventure to restore this sleek, retro-futuristic relic!

[Dunham]’s fascination with the Predicta stems from its historical significance and bold design. At a time when television was making its way into American homes, the Predicta dared to be different with its swivel-mounted picture tube and early printed circuit boards. Despite its brave aesthetics, the Predicta’s ambition led to notorious reliability issues. Yet, finding one in pristine condition, sealed and untouched for over six decades, is like unearthing a technological time capsule.

What makes this story unique is [Dunham]’s connection to both broadcasting and his craft. As a ventriloquist inspired by Edgar Bergen — whose radio shows captivated America — [Dunham] delights in restoring a TV from the same brand that first brought his idol’s voice to airwaves. His love for storytelling seamlessly translates into this restoration adventure.

After unboxing, [Dunham’s] team faces several challenges: navigating fragile components, securing the original shipping brace, and cautiously ramping up voltage to breathe life into the Predicta. The suspense peaks in the satisfying crackle of static, and the flicker of a 65-year-old screen finally awakened from slumber.

Have you ever come across an opportunity like this? Tell us about your favorite new old stock find in the comments. Buying these can be a risk, since components have a shelf life. We appreciate when these old TVs play period-appropriate shows. Who wants to watch Game of Thrones on a Predicta?

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RedBox In The 80s: Meet The VHS Vending Behemoth

Redbox was a company with a moderately interesting business model—it let you rent DVDs from automated kiosks. It’s an idea so simple it’s almost surprising it didn’t appear sooner. Only, it did—all the way back in the VHS age!

Meet the Video Vendor. YouTuber [SpaceTime Junction] was able to track down one of these rare machines, which apparently formerly served an Ohio rental outlet called Kohnen’s. It’s a monstrous thing that stands taller and about three times wider than traditional vending machines, and it could hold up to 320 tapes in its robotic magazine. It’s got lashings of woodgrain, a green-on-black CRT, and the beautiful kind of clicky keys that went away after the 1980s.

[SpaceTime Junction] has a bunch of videos up on the machine, and you even get to see it powered up.  It’s a little difficult to see what’s going on, because the machine is something like nine feet wide and it’s all shot in vertical video. There isn’t a whole lot of content on these obscurities out there, so this is a great place to start. Apparently, there were recently a hundred or more of these found living in a Texas warehouse according to Reddit, so we might see more of these popping up online soon. [SpaceTime Junction] has toured that facility, too.

You can read more about the fall of Redbox, or the cleanup afterwards, in our prior coverage.

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The Audiophile Carrot

The widely quoted carrot factoid that the vegetable’s orange colour is the result of patriotic Dutch farmers breeding them that way may be an urban myth, but it’s certainly true that they can pass an audio signal in a time of need. [Julian Krause] follows up on a Reddit meme of a carrot being used to join two phono plugs, and appears to find the organic interconnect to be of good quality.

We had to admit a second look at a calendar to be sure that it’s not April 1st, but while his manner is slightly tongue in cheek it seems he’s really characterising the audio performance of a carrot. What he finds is a bit of attenuation, some bass cut, and an intrusion of RF interference pickup, but surprisingly, not a bad distortion figure.

Of course, we’re guessing the real point of the exercise is to poke fun at the world of excessive hi-fi equipment, something we’ve been only too glad to have a go at ourselves from time to time. But if the tests are to be taken at face value it seems that in a pinch, a carrot will do as a means to hook together line level audio cables, no doubt lending a sweet and crunchy overtone to the result. The video is below the break, for your entertainment.

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A Tube Stereo Amplifier, From Scratch

A conventional tube amplifier has a circuit whose fundamentals were well in place around a hundred years ago, so there are few surprises to be found in building one today. Nevertheless, building one is still a challenge, as [Mike Freda shows us with a stereo amplifier in the video below the break.

The tubes in question are the 12AU7 double triode and 6L6 tetrode, in this case brand new PSVANE parts from China. The design is a very conventional single-ended class A circuit, with both side of the double triode being used for extra gain driving the tetrode. The output uses a tapped transformer with the tap going to the other grid in the tertode, something we dimly remember as being an “ultra-linear” circuit.

There’s an element of workshop entertainment in the video, but aside from that we think it’s the process of characterising the amp and getting its voltages right which is the take-away here. It’s not something many of us do these days, so despite the apparent simplicity of the circuit it’s worth a look.

These modern tubes come from a variety of different sources, we’ve attempted to track them down in the past.

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