Australian Library Uses Chatbot To Imitate Veteran With Predictable Results

April 26, 2024 by Lewin Day 3 Comments

The educational sector is usually the first to decry large language models and AI, due to worries about cheating. The State Library of Queensland, however, has embraced the technology in controversial fashion. In the lead-up to Anzac Day, the primarily Australian war memorial holiday, the library released a chatbot intended to imitate a World War One veteran. It went as well as you’d expect.

*The highlighted line was apparently added to the chatbot’s instructions later on to help shut down tomfoolery.*

Twitter users immediately chimed in with dismay at the very concept. Others showed how easy it was to “jailbreak” the AI, convincing Charlie he was actually supposed to teach Python, imitate Frasier Crane, or explain laws like Elle from Legally Blonde. One person figured out how to get Charlie to spit out his initial instructions; these were patched later in the day to try and stop some of the shenanigans.

From those instructions, it’s clear that this was supposed to be educational, rather than some sort of macabre experiment. However, Charlie didn’t do a great job here, either. As with any Large Language Model, Charlie had no sense of objective truth. He routinely spat out incorrect facts regarding the war, and regularly contradicted himself.

Generally, any plan that includes the words “impersonate a veteran” is a foolhardy one at best. Throwing a machine-generated portrait and a largely uncontrolled AI into the mix didn’t help things. Regardless, the State Library has left the “Virtual Veterans” experience up at the time of writing.

The problem with AI is that it’s not a magic box that gets things right all the time. It never has been. As long as organizations keep putting AI to use in ways like this, the same story will keep playing out.

Build Your Own Class-E Musical Tesla Coil

April 26, 2024 by Lewin Day 1 Comment

We’ve all seen a million videos online with singing Tesla coils doing their thang. [Zach Armstrong] wasn’t content to just watch, though. He went out and built one himself! Even better, he’s built a guide for the rest of us, too!

His guide concerns the construction of a Class-E solid state Tesla coil. These are “underrated” in his opinion, as they’re simple, cheap, and incredibly efficient. Some say up to 95% efficient, in fact! It’s not something most Tesla coil fans are concerned with, but it’s nice to save the environment while making fun happy sparks, after all.

[Zach]’s guide doesn’t just slap down a schematic and call it good. He explains the theory behind it, and the unique features too. He uses an adjustable Schmitt trigger oscillator for the build, and he’s naturally given it an audio modulation capability because that’s a good laugh, too.

If you’ve ever wanted to convince you’re friends you’re incredibly smart and science-y, you can’t go wrong with a singing Tesla coil. This beats out Jacob’s ladder and most other plasma experiments for sheer mad scientist cred.

Have fun out there! Video after the break.

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The Hunt For MH370 Goes On With Barnacles As A Lead

April 22, 2024 by Lewin Day 41 Comments

On March 8, 2014, Malaysia Airlines Flight 370 vanished. The crash site was never found, nor was the plane. It remains one of the most perplexing aviation mysteries in history. In the years since the crash, investigators have looked into everything from ocean currents to obscure radio phenomena to try and locate the plane. All have thus far failed to find the wreckage.

It was on July 2015 when a flaperon from the aircraft washed up on Réunion Island. It was the first piece of wreckage found, and it was hoped it could provide clues to the airliner’s final resting place. While it’s yet to reveal a final answer as to the aircraft’s fate, some of the ocean life living on it could help investigators need to find the plane. The picture is murky right now, but in an investigation where details are scarce, every little clue helps.

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Radio Frequency Burns, Flying A Kite, And You

April 21, 2024 by Lewin Day 22 Comments

Most hams can tell you that it’s possible to get a nasty RF burn if you accidentally touch an antenna while it’s transmitting. However, you can also cop a nasty surprise on the receiving end if you’re not careful, as explained in a video from [Grants Pass TV Repair].

*It’s hard to see in a still image, but the RF burns from the kite antenna actually generate a little puff of smoke on contact.*

An experiment was used to demonstrate this fact involving a kite and a local AM broadcaster. A simple calculation revealed that an antenna 368 feet and 6 inches long would be resonant with the KAJO Radio signal at 1.270 MHz. At half the signal’s wavelength, an antenna that long would capture plenty of energy from the nearby broadcast antenna.

Enter the kite, which served as a skyhook to loft an antenna that long. With the wire in the air picking up a strong signal from the AM radio tower, it was possible to get a noticable RF burn simply by touching the end of the antenna.

The video explains that this is a risky experiment, but not only because of the risk of RF burn itself. It’s also easy to accidentally get a kite tangled in power lines, or to see it struck by lightning, both of which would create far greater injuries than the mild RF burn seen in the video. In any case, even if you know what you’re doing, you have to be careful when you’re going out of your way to do something dangerous in the first place.

AM radio towers aren’t to be messed with; they’ve got big power flowing. Video after the break.

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AM Radio Broadcast Uses Phasor To Let Eight Towers Spray One Big Signal

April 20, 2024 by Lewin Day 8 Comments

If you’re in the commercial AM radio business, you want to send your signal as far and wide as possible. More listeners means you can make more ad revenue, after all. [Jeff Geerling] recently visited a tower site for WSDZ-AM, which uses a full eight towers to broadcast its 20kW AM signal. To do that, it needs a phasor to keep everything in tune. Or, uh… phase.

The phasor uses a bunch of variable inductors and capacitors to manage the phase of the signal fed to each tower. Basically, by varying the phase of the AM signal going to each of the 8 transmitter towers, it’s possible to tune the directionality of the tower array. This allows the station to ensure it’s only broadcasting to the area it’s legally licensed to do so.

The tower array is also configured to broadcast slightly differently during the day and at night to account for the differences in propagation that occur. A certain subset of the 8 towers are used for the day propagation pattern, while a different subset is used to shape the pattern for the night shift. AM signals can go far farther at night, so it’s important for stations to vary their output to avoid swamping neighbouring stations when the sun goes down.

[Jeff’s] video is a great tour of a working AM broadcast transmitter. If you’ve ever wondered about the hardware running your local commercial station, this is the insight you’re looking for. AM radio may be old-school, but it continues to fascinate us to this day. Video after the break.

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Bad Experiences With A Cheap Wind Turbine

April 20, 2024 by Lewin Day 44 Comments

If you’ve got a property with some outdoor space and plenty of wind, you might consider throwing up a windmill to generate some electricity. Indeed, [The Broject List] did just that. Only, his experience was a negative one, having purchased a cheap windmill online. He’s warning off others from suffering the same way by explaining what was so bad about the product he bought.

The windmill in question was described as a “VEVOR Windturbine”, which set him back around 100 euros, and claimed to be capable of producing 600 watts at 12 volts. He starts by showing how similar turbines pop up for sale all over the Internet, with wildly inflated specs that have no relation to reality. Some sellers even charge over 500 euros for the same basic device.

He then demonstrates the turbine operating at wind speeds of approximately 50 km/h. The output is dismal, a finding also shared by a number of other YouTube channels out there. Examining the construction of the wind turbine’s actual generator, he determines that it’s nowhere near capable of generating 600 watts. He notes the poorly-manufactured rotor and aluminium coils as particular disappointments. He concludes it could maybe generate 5 watts at most.

Sadly, it’s easy to fall into this trap when buying online. That’s where it pays to do your research before laying down your hard-earned cash. Continue reading “Bad Experiences With A Cheap Wind Turbine” →

Building A Giant Boardgame Isn’t Easy

April 19, 2024 by Lewin Day 8 Comments

[Stevenson Streeper] is a maker, and was recently charged with a serious mission. He had to prototype, design, and build a board game. A software-controlled board game, that is, and one that was 400 square-feet in size. As you might imagine, this ended up being a tall order, and he’s been kind enough to share his tale on his blog.

His client’s idea was for a giant interactive game board akin to the glowing disco floors of old. It had to play a game approximating the rules of “The Floor Is Lava.” It had to handle up to 20 players at a time, too.

[Stevenson] runs a company that delivers “Activations”—basically big showpieces for customers willing to pay. This wasn’t his first attempt at building an immersive attraction, but it was a big job, and a challenging one at that. He explains the difficulties that came about from a limited crew, limited timeline, and a number of difficult missteps. Hurdles included surprise unusable off-the-shelf hardware and the difficulty of hand-sanding 144 tiles of polycarbonate. One weeps for the project’s plight early on – if only the AliExpress tiles were documented.

He may have bitten off more than he could chew, and yet—the project was finished and to a decent degree of functionality success. That’s to be applauded, and [Stevenson] learned a ton along the way. Big projects can be daunting and can put you in a bind. As this story demonstrates, though, perseverance often gets you somewhere okay in the end. Video after the break.

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