Spy Tech: The GPS Numbers Station

June 8, 2026 by 21 Comments

We’ve talked before about number stations — mysterious shortwave transmitters repeating numbers, presumably for clandestine purposes. But, of course, the mere fact that they are unusual makes them stand out. The best place to hide something is in plain sight. In the old days, a broadcaster might slip a fake news story in mentioning a name that has a secret meaning, for example. But according to [Steven Murdoch], the United States has an even more obvious hiding place for a numbers station: inside GPS.

Every L1 C/A navigation message is a 176-bit field known by the affectionate moniker: Subframe 4, Page 17. The GPS specification says it is for “special messages.” No one has disclosed what those messages might be.

[Murdoch] at University College London analyzed over 12 million GPS packets from 2007 to 2026, trying to understand what was in this field. You might think 176 bits isn’t much, and you are right. But the L1 C/A signal carries 50 bits per second, and each frame is 1,500 bits. As [Murdoch] points out: “every bit must earn its place.” Each subframe is 300 bits, so this mysterious signal is 12% of the subframe. It must be important to someone.

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Revisiting Using AI Coding Assistants: You’re Holding It Wrong Edition

June 8, 2026 by 109 Comments

After scathing accusations of skimping on due diligence, as well as other feedback to my article on trying to use an ‘AI coding assistant’ for the first time, the only rational, academic response is to lick one’s wounds following a particularly bruising peer review and try to address the raised issues. Reality after all does not care about one’s feelings, and there may be more to this AI assistant technology that can be coaxed out with a more in-depth look.

To this end I’ll do my best to try and work through each raised point, criticism and accusation, to see what I – and perhaps others – can learn of this endeavor. Said points include the use of the wrong frontend – i.e. Copilot – and the wrong model – being Claude Haiku 4.5 – as well as the egregious flaw on my end of ‘prompting wrong’.

For the sake of due diligence the best frontend and models will be investigated for particular tasks, with finally the verbal minefield of ‘prompt engineering’ examined for industry-standard approaches.

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Goddard The Robot Dog Brought To Life

June 8, 2026 by 1 Comment

There’s not much more nostalgic for many than good ole’ Jimmy Neutron. This was true for [Kiara], who saw the gorgeous pupper Goddard and wanted him for herself. Of course, there was no solution other than to make an animatronic version of the robot dog.

Starting with some files ripped from a Jimmy Neutron GameCube game, Goddard was designed digitally before being printed in life size. Of course, for a true reproduction of the robot dog, the parts had to be prepped and painted in the iconic chrome and purple. A real plasma ball was used for the brain, and linear actuators were used for the legs. The head was able to be moved around similarly to professional animatronics using fishing line and servos. Put together the entire finished pup, looks incredible.

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Fixing The Failure Of The Reevo

June 8, 2026 by 40 Comments

There are a lot of traditional features of a bike that rarely change. The spokes, the chain, and the inability for it to take off like a rocket, to mention a few. None of these are features of the Reevo, a bike that tried, and mostly failed, to innovate the traditional electric bike. [Berm Peak], an individual with more time on two wheels than the entire Reevo team ever had, tried his hand at fixing the Reevo’s many problems.

[Berm Peak] has had a go at the Reevo before, but this time he had to go a lot deeper. Before any real work could be done on the Reevo, the controller needed to be jailbroken since the only way to use most features required an app that wasn’t available. Surprisingly, the controller boards were found to be well labeled, and with some trial and error, the protocols could be reverse-engineered.

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Repairing A Apple PowerBook 150 With Serious Issues

June 7, 2026 by 2 Comments

Sometimes you purchase an old device that is very cheap for a good reason. So too with the 1995 Apple PowerBook 150 that [Hugh Jeffreys] purchased for a single Aussie buck back in 2018. After finally taking it off the shelf recently, the issues are very apparent. Without even trying to turn it on, the visible damage ranges from the display that’s gone full vinegar with wolverine scratches, to the snapped hinge. Naturally the HDD also turned out to be dead.

Without a functioning display there was little point in continuing, so the disassembly started there, revealing many broken plastic clips. The cause of the vinegar symptom is the degrading polarizer, which with some finesse can be removed like a thick screen protector. Fortunately, here it’s put on top of the glass layer of the display, so after peeling it off the remaining glue can be safely dissolved and scraped away.

Inside the case the RTC battery was found to have started leaking, causing corrosion and damaging a variety of important traces for the keyboard and display. All of this damage seemed fixable, but after a while the damage was just too severe. Fortunately he was able to obtain a replacement for the affected daughter PCB, which allowed the display to come back to life, so that a new polarizer could be installed after cutting a large sheet down to size.

A replacement hinge was then printed in PETG and glued to the part of the lid where it had broken off, while snapped plastic clips were reinforced with glue where they had hung on. Finally, the IDE HDD was replaced with a CF card via an IDE adapter and the entire system reassembled.

Unfortunately [Hugh] wasn’t able to immediately source or create MacOS floppies with a version that the laptop wanted to install from, so that part couldn’t be tested yet, but there’s a good chance that this old PowerBook 150 has finally been cured of at least its biggest ills, without spending much more than the original asking price.

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Desalinating Seawater With Solar And No Brine

June 7, 2026 by 39 Comments

Although desalination is very commonly used these days to convert seawater into fresh water, one of the major disadvantages of current approaches is that commercial desalination plants produce a lot of brine, which has to be dumped somewhere ideally without causing major environmental issues. A new solar-thermal method as demonstrated by [Luheng Tang] et al. was published in Light: Science and Applications, with accompanying PR article.

This method is claimed to require no pre-treatment or leave brine, using special panels that wick water across their surface and then use solar radiation to distill this water. This differs from previous similar methods through a special surface treatment that prevents build-up of salts which would require cleaning or replacement.

The salts and other contaminants that would normally end up in the brine slough off these cells and can then be further processed to recover everything from plain table salt to lithium as well as gold, uranium and other substances of interest that are prevalent in seawater.

So far these self-cleaning cells have been tested with water from a number of oceans with a claimed 74% solar-to-vapor conversion efficiency and nearly 100% salt extraction. As always the challenge will be in scaling this up to industrial levels, but so far it looks promising.

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Hackaday Links: June 7, 2026

June 7, 2026 by 7 Comments

Christopher Nolan’s The Odyssey isn’t hitting theaters for another month or so, but if you’re already planning your trip to the cineplex, you may want to check out this page on the movie’s website which lets you view the trailer in the six (!) different formats it’s being released in.

We don’t really have an opinion on the big-screen adaptation of the epic tale as a piece of media, but from a technical standpoint, it’s interesting to see how the viewing experience changes between the 70mm IMAX version with an aspect ratio of 1.43:1 and the 35mm cut at 2.39:1. Unfortunately, the website offers no way to approximate what the movie will look like once compressed, streamed over the Internet, and displayed on a cheap TCL TV, to say nothing of how the viewing experience will be impacted should you watch the movie on your phone by way of a series of short YouTube clips while going to the bathroom. Maybe Nolan is saving that for his next film.

If you head over to the movies in one of Waymo’s vehicles, you can feel a little better about the long-term ecological impact of your trip thanks to a recently announced partnership between the autonomous car maker and B2U Storage Solutions. Under the agreement, old batteries pulled from Waymo’s fleet of self-driving electric cars will get a second life as localized grid storage.

The idea is that batteries which no longer hold enough charge to power a robo-taxi should still have enough capacity to store the energy produced by renewable sources so it can be doled out later when the demand goes up. By installing these batteries in the cities that Waymo actually operates their vehicles in, they don’t have to worry about shipping them around either — they can just yank them out of the car, and wire them right into the grid. Of course, eventually the batteries will be too cooked to adequately perform in this role as well, but this should give them a few more productive years before they get torn down and scrapped.

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