You Can Use A CRT As An Audio Amplifier Tube

July 11, 2024 by Lewin Day 36 Comments

When we talk about audio amplifier tubes, we’re normally talking about the glass little blobby things you might find in a guitar amplifier. We’re not normally talking about big ol’ color CRTs, but apparently they can do the job too. That’s what [Termadnator] is here to show us.

The CRT in question is a 14″ unit from a common garden variety Philips color TV. [Termadnator] pulled out the TV’s original circuitry, and replaced much of it with his own. He had to whip up a high-voltage power supply with a 555 and a laptop power supply, along with a bunch of fake MOSFETs pressed into service. He also had to build his own Leyden jar capacitor, too. The specifics of converting it to audio operation get a bit messy, but fear not—[Termadnator] explains the idea well, and also supplies a schematic. Perhaps the coolest thing, though, is the crazy color pattern that appears on the display when it’s working as an amp.

Sound output isn’t exactly loud, and it’s a little distorted, too. Still, it’s amusing to see an entire TV instead doing the job of a single amplifier tube. Video after the break.

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All About CRTs

June 25, 2024 by Al Williams 76 Comments

For old-timers, CRTs — cathode ray tubes — were fixtures as kids sat in front of TVs watching everything from Howdy Doody to Star Trek. But there’s at least one generation that thinks TVs and computer monitors are flat. If that describes you, you might enjoy [The 8-Bit Guy’s] coverage of how CRTs work in the video below.

CRTs were heavy, took high voltage, and had a dangerous vacuum inside, so we really don’t miss them. The phosphor on the screen had a tendency to “burn in” if you showed the same image over and over. We don’t miss that either.

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Tight Handheld CRT Asteroids Game Curses In Tuscan

June 12, 2024 by Elliot Williams 5 Comments

How many Arduini does it take to make a tiny CRT Asteroids game? [Marco Vallegi] of MVV Blog’s answer: two. One for the game mechanics and one for the sound effects. And the result is a sweet little retro arcade machine packed tightly into a very nicely 3D printed case.

If you want to learn to curse like a Tuscan sailor, you can watch the two-part video series, embedded below, in its entirety. Otherwise, we have excerpted the good stuff out of the second video for you.

For instance, we love the old-school voice synthesis sound of the Speak and Spell. Here, playback is implemented using the Talkie library for Arduino, and [Marco] is using the BlueWizard software on a dated Macbook for recording and encoding. (We’d use the more portable Python Wizard ourselves.) Check out [Marco] tweaking the noise parameters here to get a good recording.

And since the Talkie Arduino library uses PWM on a digital output pin to create the audio, the high-frequency noise was freaking out his simple transistor amplifier. Here, [Marco] adds a feedback capacitor to cancel that high-frequency hash out.

The build needs to be quite compact, and the stacked-Arduino-with-PCB-case design is tight. And the 3D-printed case has a number of nice refinements that you might like. We especially like the use of thin veneers that cover the case all around with the build-plate’s surface texture, and the contrasting “Asteroids” logos are very nice.

All in all, this is a really fun build that’s also full of little details that might help you with your own projects. Heck, even if it just encourages you to play around with the Talkie library, it’s worth your time in our opinion. And while you’re at it, you can turn on the subtitles and pick up some vocab that’ll make your nonna roll over in her grave.

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Keeping Alive The Future Of Cars, 1980s Style

April 21, 2024 by Jenny List 18 Comments

Here at Hackaday we’re a varied bunch of writers, some of whom have careers away from this organ, and others whose work also appears on the pages of other publications in different fields. One such is our colleague [Lewin Day], and he’s written a cracking piece for The Autopian about the effort to keep an obscure piece of American automotive electronic history alive. We think of big-screen control panels in cars as a new phenomenon, but General Motors was fitting tiny Sony Trinitron CRTs to some models back in the late 1980s. If you own one of these cars the chances are the CRT is inoperable if you’ve not encountered [Jon Morlan] and his work repairing and restoring them.

Lewin’s piece goes into enough technical detail that we won’t simply rehash it here, but it’s interesting to contrast the approach of painstaking repair with that of replacement or emulation. It would be a relatively straightforward project to replace the CRT with a modern LCD displaying the same video, and even to use a modern single board computer to emulate much of a dead system. But we understand completely that to many motor enthusiasts that’s not the point, indeed it’s the very fact it has a frickin’ CRT in the dash that makes the car.We’ll probably never drive a 1989 Oldsmobile Toronado. But we sure want to if it’s got that particular version of the future fitted.

Lewin’s automotive writing is worth watching out for. He once brought us to a motorcycle chariot.

Who’s Afraid Of A CRT?

April 13, 2024 by Jenny List 25 Comments

Older consumer electronic devices follow a desirability curve in which after they fall from favour they can’t be given away. But as they become rarer, they reach a point at which everyone wants them. Then, they can’t be had for love nor money. CRT TVs are now in the first stage, they’re bulky and lower-definition than modern sets, and thus thrift stores and dumpsters still have them in reasonable numbers. To retrogamers and other enthusiasts, this can be a bonanza, and when he saw a high-end late-model JVC on the sidewalk [Chris Person] wasted no time in snapping it up. It worked, but there were a few picture issues, so he set about fixing it.

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Get Today’s Forecast In Classic 90s Weather Channel Style

April 10, 2024 by Dan Maloney 9 Comments

Remember when The Weather Channel actually had weather? It’s been a while, but we sure remember what a boon Local on the 8’s was when getting ready for the day. Not having to wait for the low-information national forecast on the morning shows or putting up with the antics of [Willard Scott] or [Al Roker] was just icing on the cake.

Recreating the retro look and feel of the Weather Channel experience is what this 1990s-style weather feed is all about, and we have to say that [Mitchell Scott] knocked it out of the park. Luckily, a lot of the heavy lifting was done already thanks to the WeatherStar 4000+ emulator project, which renders forecasts using online weather APIs in the distinctive retro graphics The Weather Channel used back in the day. He combined the graphics with the original smooth jazz soundtracks that TWC used back then; they’re online, because of course they are.

To really sell the look, [Mitchell] tracked down a period-correct Zenith TV with a 9″ CRT to display the feed from a Raspberry Pi 4’s composite video output. Why such a small screen? Easy. [Mitchell] wanted it on a shelf behind him to be visible during videoconferences. It’s a bit of a weird flex, but we respect it. Getting the composite video output working was a bit of a chore, as was tricking the TV into starting up on channel 14 so the feed is instantly visible.

The nostalgia is strong with this one, especially for weather geeks. For a more in-depth look at how The Weather Channel brought those local forecasts to cable, make sure you check out how the WeatherStar box was reverse-engineered.

Thanks to [USA-RedDragon] for the tip.

Video Killed The Radio Alarm Clock

March 29, 2024 by Bryan Cockfield 4 Comments

For decades now, MTV has been on a bizarre trajectory given its original name was an acronym for Music Television. In the original days in the 80s and 90s it kept mostly true to its name, but starting around two decades ago they expanded into reality and other non-musical television programming and have now left it largely behind. Plenty of those who grew up in its heyday have an understandable amount of nostalgia for the channel as a cultural touchstone, and [Derf] used MTV archival footage to build a video alarm clock which helps him keep in tune with the past.

To keep the appropriate 80s aesthetic, the build uses a portable TV from the late 80s with its original CRT. The video files are hosted on more modern technology though, in this case a Raspberry Pi. The Pi is set up to run a python script which launches the VLC media player with a playlist loaded with video files, in this case a long list of MTV shows. Some configuration needs to be done to get it to output to the old CRT properly which depends on the hardware used, but once that’s in place it’s ready to be used as an alarm. [Derf] is using a smart outlet to power the TV at the appropriate time, and a cron job which starts the video player simultaneously at a somewhat random point in the playlist.

As far as retro TVs go, having one as an alarm clock is certainly a novel idea. We have seen a few others in the past, though, one to play the golden age of The Simpsons, and another that recreates the nostalgia of 90s cable television complete with a preview channel and era-appropriate commercials.

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