Classic Heathkit OL-1 Scope Gets Some TLC

These days, not only are oscilloscopes very common, but even a cheap instrument today would have been the envy of the world’s greatest labs not that long ago. But back in the day, the home experimenter basically had two choices: buy a surplus scope that a big company was getting rid of or build a Heathkit. [Radiotvphononut] bought an old Heathkit OL-1 scope at an estate sale and set about putting it back in service.

If you are used to a modern scope, you’ll be amazed at how simple a scope like this can be. A handful of tubes and a CRT is the bulk of it. Of course, the OL-1 is an analog scope with a 400 kHz bandwidth. It did, however, have two channels, which was a rarity at the time.

The OL-1 was sold for a few years up to 1956 and cost about $30 as a kit. There was a version with a larger screen (five whole inches) that cost an extra $40, so you can bet there were more OL-1s sold since $40 was a big ask in 1956. While they don’t seem like much today, you were probably the envy of the ham club in 1956 when you lugged this in for show and tell.

This is a long video, but it pays off at the end. Overall, this was a more capable scope than the $66 scope from 10 years earlier we looked at. Did you ever wonder how people visualized signals before the CRT? Funny, we did too.

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Heathkit Signal Generator Gets An Update

[DTSS_Smudge] correctly intuits that if you are interested in an old Heathkit signal generator, you probably already know how to solder. So, in a recent video, he focused on the components he decided to update for safety and other reasons. Meanwhile, we get treated to a nice teardown of this iconic piece of test gear.

If you didn’t grow up in the 1960s, it seems strange that the device has a polarized line cord with one end connected to the chassis. But that used to be quite common, just like kids didn’t wear helmets on bikes in those days.

A lot of TVs were “hot chassis” back then, too. We were always taught to touch the chassis with the back of your hand first. That way, if you get a shock, the associated muscle contraction will pull your hand away from the electricity. Touching it normally will make you grip the offending chassis hard, and you probably won’t be able to let go until someone kindly pulls the plug or a fuse blows.

These signal generators were very common back in the day. A lot of Heathkit gear was very serviceable and more affordable than the commercial alternatives. In 1970, these cost about $32 as a kit or $60 already built. While $32 doesn’t sound like much, it is equivalent to $260 today, so not an impulse buy.

Some of the parts are simply irreplaceable. The variable capacitor would be tough to source since it is a special type. The coils would also be tough to find replacements, although you might have luck rewinding them if it were necessary.

We are spoiled today with so many cheap quality instruments available. However, there was something satisfying about building your own gear and it certainly helped if you ever had to fix it.

There was so much Heathkit gear around that even though they’ve been gone for years, you still see quite a few units in use. Not all of their gear had tubes, but some of our favorite ones did.

Libre Space Foundation Aims To Improve Satellite Tech

There’s no shortage of movies, TV shows, and books that show a dystopian future with corporations run amok in outer space with little or no effective oversight. Dune, The Expanse, and The Dispossessed spring to mind as predicting different aspects of this idea, but there are plenty of other warnings throughout sci-fi depicting this potential future. One possible way of preventing this outcome is by ensuring that space is as open-sourced as possible and one group, the Libre Space Foundation (LSF), is working towards this end. Their latest is a project with Ondsel to develop and model a satellite deploying mechanism using almost entirely open source software.

The LSF had already designed the PICOBUS satellite launcher system that flew to space in 2022 and deployed a number of CubeSats, but the group needed more information about how the system would perform. They turned to Ondsel to help develop a multi-body dynamics (MBD) solver, managing simulations with mass-spring-damper models. The satellite launcher includes a large constant-force spring that pushes the CubeSats out of the device once the door is opened, and the model can now simulate their paths in space without gravity. The team will launch their next set of satellites sometime next year on an RFA-ONE rocket.

The LSF maintains a huge database of their open source space projects, including this one, on their GitLab page. Although it might seem like small potatoes now, the adoption of open source software and hardware by space-fairing entities can help further the democratization of low Earth orbit.

Thanks to [johnad] for the tip!

Strange English Teaching Computer Might Have Been Big In Japan

[Ctrl-Alt-Rees] bought something strange on an auction site: a Japanese Cefucom-21 from 1983. No? Didn’t ring a bell for us either. The legend on the front boldly proclaims: “CCI Multipurpose SLAP Computer,” so maybe it is some kind of computer, but it is definitely strange. For one thing, the “screen” isn’t a screen at all. [Rees] has found that it has something to do with teaching English. You can see the odd beast in the video below.

We don’t know how common these were in Japan, but they appear to be virtually unknown everywhere else. Inside is a Z80 computer based on a  Sanyo PHC-25, which is a little better known.

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Save A Packet, Use Cheap Co-Ax!

Anyone who works with radio transmitters will know all about matching and impedance, and also about the importance of selecting the best co-axial cable connecting transistor and antenna. But here’s [Steve, KD2WTU] with a different take, he’s suggesting that sometimes a not-so-good co-ax choice can make the grade. He’s passing up expensive 50 ohm cable in favour of the cheap and ubiquitous 75 ohm RG6 cable used in domestic TV and satellite receiver installations.

Fighting that received wisdom, he outlines the case for RG6. It’s cheap and it has a surprisingly low loss figure compared to some more conventional choices, something that shouldn’t be a surprise once we consider that it’s designed to carry GHz-plus signals. Where it loses is in having a lower maximum power rating. Power shouldn’t be a problem to a shoestring ham for whom 100W is QRO. Another issue is that 75 ohm coax necessitates a tuner for 50 ohm transmitters. It also has the effect of changing the resonance of some antennas, meaning a few mods may be in order.

So we’re convinced, and with the relatively QRP shack here we can’t see RG6 being a problem. Maybe it’s something to try in out next antenna experiment. Meanwhile if you’re interested in some of the background on co-ax impedance choices, we’ve been there before.

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Feeling A Pong Of Nostalgia: Does It Hold Up In 2024?

We have probably all been there: that sudden memory of playing a (video) game and the good memories associated with said memory. Yet how advisable is it to try and re-experience those nostalgic moments? That’s what [Matt] of the Techmoan YouTube channel decided to give a whirl when he ordered the Arcade1Up Pong 2 Player Countercade game system. This comes loaded with multiple variants of the Pong game, including Pong Doubles and Pong Sports, in addition to Warlords, Super Breakout and Tempest. This unit as the name suggests allows for head-to-head two-player gaming.

This kind of ‘countercade’ system is of course much smaller than arcade versions, but you would expect it to give the Pong clones which [Matt] played as a youngster a run for their money at least. Ultimately [Matt] – after some multiplayer games with the Ms. – concluded that this particular nostalgia itch was one that didn’t have to be scratched any more. While the small screen of this countercade system and clumsy interface didn’t help much, maybe Pong just isn’t the kind of game that has a place in 2024?

From our own point of view of having played Pong (and many other ‘old’ games) on a variety of old consoles at retro events & museums, it can still be a blast to play even just Pong against a random stranger at these places. Maybe the issue here is that nostalgia is more about the circumstances of the memory and less of the particular game or product in question. Much like playing Mario Kart 64 on that 20″ CRT TV with three buddies versus an online match in a modern Mario Kart. It’s just not the same vibe.

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Hackaday Podcast Episode 293: The Power Of POKE, Folding Butterflies, And The CRT Effect

This week on the Podcast, Hackaday’s Elliot Williams and Kristina Panos joined forces to bring you the latest news, mystery sound, and of course, a big bunch of hacks from the previous week.

First up in the news: we’ve extended the 2024 Supercon Add-On contest by a week! That’s right, whether you were held up by Chinese fall holidays or not, here’s your chance to get in on this action.

A square image with the Supercon 8 Add-On Contest art featuring six SAOs hanging from lanyards.We love to see the add-ons people make for the badge every year, so this time around we’re really embracing the standard. The best SAOs will get a production run and they’ll be in the swag bag at Hackaday Europe 2025.

What’s That Sound pretty much totally stumped Kristina once again, although she kind of earned a half shirt. Can you get it? Can you figure it out? Can you guess what’s making that sound? If you can, and your number comes up, you get a special Hackaday Podcast t-shirt.

Then it’s on to the hacks, beginning with what actually causes warping in 3D prints, and a really cool display we’d never heard of. Then we’ll discuss the power of POKE when it comes to live coding music on the Commodore64, and the allure of CRTs when it comes to vintage gaming. Finally, we talk Hackaday comments and take a look at a couple of keyboards.

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Download in DRM-free MP3 and savor at your leisure.

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