The Long Strange Trip To US Color TV

We are always fascinated when someone can take something and extend it in a clever way without changing the original thing. In the computer world, that’s old hat. New computers improve, but can usually run old software. In the real world, the addition of stereo to phonograph records and color to photography come to mind.

But there are few stories as strange or wide-ranging as the path to provide color TV. And it had to be done in a way that a color set could still get a black and white picture and black and white sets could still watch a color signal without color. You’d think there would be a “big bang” moment where color TV burst on the scene — no pun involving color burst intended. But there wasn’t. Instead, there was a long, twisted path with many competing interests and ideas to go from a world in black and white to one tinted with color phosphor.

Background

In 1928, Science and Invention magazine had plans for building a mechanical TV (although not color)

It is hard to imagine, but John Logie Baird transmitted color images as early as 1928 using a mechanical scanner. Bell Labs had a demonstration system, also mechanical, in 1929. Baird broadcast using his system in 1938. Even earlier, around 1900, there were attempts to create mechanical color image systems. Those systems were fickle or impractical, though.

Electronic scanning was the answer, but World War II froze most consumer electronics development. Baird showed an electronic color system in late 1944. However, it would be 1953 before NTSC (the National Television System Committee) adopted the standard color TV signal for the United States. It would be almost 20 years later before SECAM and PAL were standardized in other parts of the world.

Of course, these are all analog standards. The world’s gone digital now, but for nearly 50 years, analog color TV was the way people consumed TV in their homes. By 1941, NTSC produced a standard in the United States, but not for color TV. TV adoption didn’t really take off until after the war. But by 1950, the US had some 6 million TV sets.

This was both a plus — a large market — and a negative. No one wanted to obsolete those 6 million sets. Well, at least, the government regulators and consumers didn’t. But most color systems would be incompatible with those existing black and white sets. Continue reading “The Long Strange Trip To US Color TV”

RCA’s Clear Plastic TV Wowed Crowds In 1939

In the United States in 1939, television sets still had a long way to go before they pretty much sold themselves. Efforts to do just that are what led to RCA’s Lucite Phantom Telereceiver, which aimed to show people a new way to receive broadcast media.

Created for the 1939 World’s Fair, the TRK-12 Lucite Phantom Telereceiver introduced people to the concept of television. Production models were housed in contemporary wood cabinets, but the clear acrylic (itself also a relatively new thing) units allowed curious potential customers to gaze within, and see what was inside these devices.

One interesting feature is the vertically-mounted cathode ray tube, which reflects off a mirror in the top cover of the cabinet for viewing. This meant that much of the bulk of the TRK-12 could be vertical instead of horizontal. Important, because the TRK-12 was just over a meter tall and weighed 91 kilograms (or just over 200 lbs.)

Clearly a luxury item, the TRK-12 sold for $600 which was an eye-watering sum for the time. But it was a glimpse of the future, and as usual, the future is made available a few ticks early to those who can afford the cost.

Want to see one in person? You might be in luck, because an original resides at the MZTV Museum of Television in Toronto, Canada.

50-Year-Old 8-Track Changer Repair And Hack

For reasons still unclear, [Techmoan] has procured an RCA 8-track changer that holds five tape cartridges in a custom carrier. It somewhat works, but had a bit of mechanical issues here and there which needed some maintenance. Additionally, the player is designed for the US market and 60 Hz mains, but [Techmoan] is in the UK with 50 Hz.

Although electronics are used for the basic tape player portion, everything else is operated by mechanical gears, levers, and motors. The system plays both sides of each tape cartridge through to completion, and then switches automatically to the next one in the stack. Cartridges could be up to 90 minutes each, making for over seven hours of playing time. Oddly, the system does not repeat automatically after the fifth tape ends –operator intervention is required. It’s not entirely clear whether these carousels were primarily intended to play background music inside businesses, or built for niche consumer applications.

After discovering there was no setting to adjust the tape’s speed for 50/60 Hz operation, [Techmoan] could have ordered or fabricated a larger-diameter pulley for the motor drive shaft. But in true hacker style, he instead solves the problem with cellophane packing tape. By trial and error, he builds up the pulley diameter by winding lengths of tape until the music sounds just “good enough” to his ear. Then he pulls out the wow and flutter meter to really zero in — and gets it bang on. He says that this changer is needed for a future video, so we’re looking forward to see how it will be employed.

If you like these old mechanical logic controls, check out the video below the break. If you want dig into the workings of an 8-track player, check out Jenny List’s retro teardown from 2017.  Does anyone still use 8-track tapes any more?

Continue reading “50-Year-Old 8-Track Changer Repair And Hack”

Two pairs of boards described in the article, with toggle switches and RCA jacks, shown interconnected, LEDs on all four boards lit up.

Boards For Playful Exploration Of Digital Protocols

Teaching people efficiently isn’t limited to transmitting material from one head to another — it’s also about conveying the principles that got us there. [Mara Bos] shows us a toolkit (Twitter,
nitter link
) that you can arm your students with, creating a small playground where, given a set of constraints, they can invent and figure communication protocols out on their own.

This tool is aimed to teach digital communication protocols from a different direction. We all know that UART, I2C, SPI and such have different use cases, but why? Why are baud rates important? When are clock or chip select lines useful? What’s the deal with the start bit? We kinda sorta figure out the answers to these on our own by mental reverse-engineering, but these things can be taught better, and [Mara] shows us how.

Gently guided by your observations and insights, your students will go through defining new and old communication standards from the ground up, rediscovering concepts like acknowledge bits, bus contention, or even DDR. And, as you point out that the tricks they just discovered have real-world counterparts, you will see the light bulb go on in their head — realizing that they, too, could be part of the next generation of engineers that design the technologies of tomorrow.

Continue reading “Boards For Playful Exploration Of Digital Protocols”

RCA Plug Plays Sixteen-Minute Chiptune Piece, All By Itself

Frequenters of arcades back in the golden age of video games will likely recall the mix of sounds coming from a properly full arcade, the kind where you stacked your quarters on a machine to stake your claim on being next in line to play. They were raucous places, filled with the simple but compelling sounds that accompanied the phosphor and silicon magic unfolding all around.

The days of such simple soundtracks may be gone, but they’re certainly not forgotten, with this chiptunes generator built into an RCA plug being both an homage to the genre and a wonderful example of optimization and miniaturization. It’s the work of [girst] and it came to life as an attempt to implement [Rob Miles]’ Bitshift Variations in C Minor algorithmically generated chiptunes composition in hardware. For the first attempt, [girst] chose an ATtiny4 as the microcontroller, put it and the SMD components needed for a low-pass filter on a flex PCB, and wrapped the whole thing around a button cell battery. Stuffed into the shell of an RCA plug, the generator detects when it has been inserted into an audio input jack and starts the 16-minute piece. [girst] built a second version, too, using the Padauk PSM150c “Three-Cent Microcontroller” chip.

This is quite an achievement in chiptunes minimization. We’ve seen chiptunes in 32 bytes, Altoids tin chiptunes, and an EP on a postage-stamp-sized PCB, but this one might beat them all on size alone.

Continue reading “RCA Plug Plays Sixteen-Minute Chiptune Piece, All By Itself”

Restoring A 1949 Golden Throat Radio

[Mr. Carlson] has a really beautiful old 1949-era radio to restore and you can watch him do it in a comprehensive video, below. We aren’t sure what we were more amused by: the odd speaker that looks like a ceiling air vent or the sticker on the back certifying that the radio produces the tone of the “golden throat” signed by RCA’s chief engineer.

Electrically, the radio didn’t look that remarkable. Of course, the capacitors were presumed bad and replaced. The video made us remember how much we hated restringing dial radios!

Continue reading “Restoring A 1949 Golden Throat Radio”

RCA Created Video Records Too Late

It is easy to find technology success stories: the PC, DVD, and cell phone are all well-documented tales. However, it is a little harder to find the stories behind the things that didn’t quite take off as planned. As the old saying goes, “success has many parents but failure is an orphan.” [Technology Connections] has a great video about RCA’s ill-fated SelectaVision video disc systems. You can see part one of the video below.

RCA started working on the system in the 1960s and had they brought it to market a bit earlier, it might have been a big win. After all, until the VCR most of us watched what was on TV when it was on and had no other options. You couldn’t record things or stream things and f you didn’t make it home in time for Star Trek, you simply missed that episode and hoped you’d get luckier when and if they reran it during the summer. That seems hard to imagine today, but a product like the SelectaVision when it was the only option could have really caught on. The problem was of course, that they waited too late to bring it to market. The video also makes the point that the system contained a few too many technical compromises.

Continue reading “RCA Created Video Records Too Late”