Retrotechtacular: How Communism Made Televisions

September 29, 2023 by Jenny List 28 Comments

For those of us who lived through the Cold War, there’s still an air of mystery as to what it was like on the Communist side. As Uncle Sam’s F-111s cruised slowly in to land above our heads in our sleepy Oxfordshire village it was at the same time very real and immediate, yet also distant. Other than being told how fortunate we were to be capitalists while those on the communist side lived lives of mindless drudgery under their authoritarian boot heel, we knew nothing of the people on the other side of the Wall, and God knows what they were told about us. It’s thus interesting on more than one level to find a promotional film from the mid 1970s showcasing VEB Fernsehgerätewerk Stassfurt (German, Anglophones will need to enable subtitle translation), the factory which produced televisions for East Germans. It provides a pretty comprehensive look at how a 1970s TV set was made, gives us a gateway into the East German consumer electronics business as a whole, and a chance to see how the East Germany preferred to see itself.

The RFT range of televisions in the Städtisches Kaufhaus exhibition center for the 1968 Leipzig Spring Fair. Bundesarchiv, CC-BY-SA 3.0

The sets in question are not too dissimilar to those you would have found from comparable west European manufacturers in the same period, though maybe a few things such as the use of a tube output stage and the lack of integrated circuits hints at their being a few years behind the latest from the likes of Philips or ITT by 1975. The circuit boards are assembled onto a metal chassis which would have probably been “live” as the set would have derived its power supply by rectifying the mains directly, and we follow the production chain as they are thoroughly checked, aligned, and tested. This plant produces both colour and back-and-white receivers, and since most of what we see appears to be from the black-and-white production we’re guessing that here’s the main difference between East and West’s TV consumers in the mid ’70s.

The film is at pains to talk about the factory as a part of the idealised community of a socialist state, and we’re given a tour of the workers’ facilities to a backdrop of some choice pieces of music. References to the collective and some of the Communist apparatus abound, and finally we’re shown the factory’s Order of Karl Marx. As far as it goes then we Westerners finally get to see the lives of each genosse, but only through an authorised lens. Continue reading “Retrotechtacular: How Communism Made Televisions” →

Black Graphics On Your TV, For A Greener World?

August 14, 2023 by Jenny List 95 Comments

Can you really save energy by carefully choosing the colors displayed on a TV screen? Under some conditions, yes. Or at least that’s the conclusion of a team at the BBC that looked at reducing the energy consumption impact of their output by using what they call Lower Carbon Graphics. In short, they’re trying to ensure that OLED displays or those with reactive backlights use less energy when displaying BBC graphics, simply by using more black.

It turns out that a lot of British households play radio stations on their TVs, and the BBC sends a static image to each screen in this mode. As part of a redesign across the organisation, the BBC removed the bright background colours from these images and replaced it with black, with a remarkable reduction in power consumption, at least on OLED and FALD screens. (On normally backlit screens, 89% of British TVs, this does nothing.)

If you look hard at their numbers, though, listening to radio on the TV is horrendously inefficient; can you imagine a radio that consumes 100 W? If the BBC really wants to help reduce media-related energy consumption, maybe they should stop broadcasting radio programming on the TV entirely.

Anyway, as we move toward a larger fraction of OLED screens, on TVs and monitors alike, it’s fun to think that darker images use up to 40% less power. Who knew that Hackaday was so environmentally friendly? Black is the new green!

Header: RIA Novosti archive/ Igor Vinogradov, CC-BY-SA 3.0.

Recreating The Golden Era Of Cable TV

July 13, 2023 by Bryan Cockfield 55 Comments

Fewer and fewer people have cable TV subscriptions these days, due to a combination of poor business practices by cable companies and the availability of alternatives to cable such as various streaming platforms. But before the rise of the Internet that enabled these alternatives, there was a short period of time where there were higher-quality channels, not too many commercials, a possibly rose-tinted sense of wonder, and where MTV actually played music. [Irish Craic Party] created this vintage cable TV network to capture this era of television history.

The hardware for this build is a Raspberry Pi driving an LCD display recovered from an old iPad. There’s a custom TV tuner which handles changing the channels and interfaces with an Apple Remote. Audio is sent through old computer speakers, and the case is built from 3D printed parts and some leftover walnut plywood to give it an era-appropriate 80s or early 90s feel. We’ve seen other builds like this before, but where this one really sets itself apart is in the software that handles the (television) programming.

[Irish Craic Party] has gone to great lengths here to recreate the feel of cable TV from decades ago. It has recreations of real channels like HBO, Nickelodeon, and FX including station-appropriate bumpers and commercials. It’s also synchronized to the clock so shows start on the half- or quarter-hour. Cartoons play on Saturday morning, and Nickelodeon switches to Nick-at-Nite in the evenings. There are even channels that switch to playing Christmas movies at the appropriate times, complete with Christmas-themed commercials.

The build even hosts a preview channel, one of the more challenging parts of the build. It continually scrolls through the channels and shows what’s currently playing and what will be showing shortly, complete with a commercial block at the top. For those who were around in the 90s it’s almost a perfect recreation of the experience of watching TV back then. It can even switch to a video game input when tuned to channel 3. There’s almost too much to go into in a short write-up so be sure to check the video after the break.

Thanks to [PCrozier] for the tip!

Continue reading “Recreating The Golden Era Of Cable TV” →

System Essentially Contradicting American Methods

July 5, 2023 by Jenny List 36 Comments

Today, acronyms such as PAL and initialisms such as NTSC are used as a lazy shorthand for 625 and 525-line video signals, but back in the days of analogue TV broadcasting they were much more than that, indeed much more than simply colour encoding schemes. They became political statements of technological prowess as nations vied with each other to demonstrate that they could provide their citizens with something essentially home-grown. In France, there was the daddy of all televisual symbols of national pride, as their SECAM system was like nothing else. [Matt’s TV Barn] took a deep dive into video standards to find out about it with an impressive rack of test pattern generation equipment.

At its simplest, a video signal consists of the black-and-while, or luminance, information to make a monochrome picture, along with a set of line and frame sync pulses. It becomes a composite video signal with the addition of a colour subcarrier at a frequency carefully selected to fall between harmonics of the line frequency and modulated in some form with the colour, or chrominance, information. In this instance, PAL is a natural progression from NTSC, having a colour subcarrier that’s amplitude modulated and with some nifty tricks using a delay line to cancel out colour shifting due to phase errors.

SECAM has the same line and frame frequency as PAL, but its colour subcarrier is frequency modulated instead of amplitude modulated. It completely avoids the NTSC and PAL phase errors by not being susceptible to them, at the cost of a more complex decoder in which the previous line’s colour information must be stored in a delay line to complete the decoding process. Any video processing equipment must also, by necessity, be more complex, something that provided the genesis of the SCART audiovisual connector standard as manufacturers opted for RGB interconnects instead. It’s even more unexpected at the transmission end, for unlike PAL or NTSC, the colour subcarrier is never absent, and to make things more French, it inverted the video modulation found in competing standards.

The video below takes us deep into the system and is well worth a watch. Meanwhile, if you fancy a further wallow in Gallic technology, peer inside a Minitel terminal.

Continue reading “System Essentially Contradicting American Methods” →

Recreating An Analog TV Test Pattern

June 9, 2023 by Bryan Cockfield 25 Comments

While most countries have switched to digital broadcasting, and most broadcasts themselves have programming on 24/7 now, it’s hard to remember the ancient times of analog broadcasts that would eventually stop sometime late at night, displaying a test pattern instead of infomercials or reruns of an old sitcom. They were useful for various technical reasons including calibrating the analog signals. Some test patterns were simply camera feeds of physical cards, but if you wanted the most accurate and reliable test patterns you’d need a Philips pattern generator which created the pattern with hardware instead, and you can build your own now because the designs for these devices were recently open-sourced. Continue reading “Recreating An Analog TV Test Pattern” →

RetroPie, Without The Pi

June 6, 2023 by Bryan Cockfield 24 Comments

The smart television is an interesting idea in theory. Rather than having the cable or satellite company control all of the content, a small computer is included in the television itself to host and control various streaming clients and other services. Assuming you have control of the software running on the computer, and assuming it isn’t turned into a glorified targeted advertising machine, this can revolutionize the way televisions are used. It’s even possible to turn a standard television into a smart TV with various Android devices, and it turns out there’s a lot more you can do with these smart TV contraptions as well.

With most of these devices, a Linux environment is included running on top of an ARM platform. If that sounds similar to the Raspberry Pi, it turns out that a lot of these old Android TV sets are quite capable of doing almost everything that a Raspberry Pi can do, with the major exception of GPIO. That’s exactly what [Timax] is doing here, but he notes that one of the major hurdles is the vast variety of hardware configurations found on these devices. Essentially you’d have to order one and hope that you can find all the drivers and software to get into a usable Linux environment. But if you get lucky, these devices can be more powerful than a Pi and also be found for a much lower price.

He’s using one of these to run RetroPie, which actually turned out to be much easier than installing a more general-purpose Linux distribution and then running various emulation software piecemeal. It will take some configuration tinkering get everything working properly but with [Timax] providing this documentation it should be a lot easier to find compatible hardware and choose working software from the get-go. He also made some improvements on his hardware to improve cooling, but for older emulation this might not be strictly necessary. As he notes in his video, it’s a great way of making use of a piece of electronics which might otherwise be simply thrown out.

Continue reading “RetroPie, Without The Pi” →

A Look At Zweikanalton Stereo Audio And Comparison With NICAM

March 19, 2023 by Maya Posch 1 Comment

With how we take stereo sound for granted, there was a very long period where broadcast audio and television with accompanying audio track were in mono. Over the decades, multiple standards were developed that provide a way to transmit and receive two mono tracks, as a proper stereo transmission. In a recent video, [Matt] over at [Matt’s Tech Barn] takes a look at the German Zweikanalton (also known as A2 Stereo) standard, and compares it with the NICAM standard that was used elsewhere in the world.

Zweikanalton is quite simple compared to NICAM (which we covered previously), being purely analog with a second channel transmitted alongside the first. Since it didn’t really make much of a splash outside of the German-speaking countries, equipment for it is more limited. In this video [Matt] looks at the Philips PM 5588 and Rohde & Schwarz 392, analyzing the different modulations for FM, Zweikanalton and NICAM transmissions and the basic operation of the modulator and demodulator equipment.

An interesting aspect of these modulations are the visible sidebands, and the detection of which modulation is used. Ultimately NICAM’s only disadvantage compared to Zweikanalton was the higher cost of the hardware, but with increased technological development single-chip NICAM solutions like the Philips SAA7283 (1995) began to reduce total system cost and by the early 2000s NICAM was a standard feature of TV chipsets, just in time for analog broadcast television to essentially become irrelevant.

Continue reading “A Look At Zweikanalton Stereo Audio And Comparison With NICAM” →