Reactivating A Harris RF-130 URT-23 Transmitter

April 8, 2023 by Al Williams 13 Comments

If you enjoy old military hardware, you probably know that Harris made quite a few heavy-duty pieces of radio gear. [K6YIC] picked up a nice example: the Harris RF-130 URT-23. These were frequently used in the Navy and some other service branches to communicate in a variety of modes on HF. The entire set included an exciter, an amplifier, an antenna tuner, and a power supply and, in its usual configuration, can output up to a kilowatt. The transmitter needs some work, and he’s done three videos on the transmitter already. He’s planning on several more, but there’s already a lot to see if you enjoy this older gear. You can see the first three below and you’ll probably want to watch them all, but if you want to jump right to the tear down, you can start with the second video.

You can find the Navy manual for the unit online, dated back to 1975. It’s hard to imagine how much things have changed in 50 years. These radios use light bulbs and weigh almost 500 pounds. [Daniel] had to get his shop wired for 220 V just to run the beast.

It is amusing that some of this old tube equipment had a counter to tell you how many hours the tubes inside had been operating so you could replace them before they were expected to fail. To keep things cool, there’s a very noisy 11,000 RPM fan. The two ceramic final amplifier tubes weigh over 1.5 pounds each!

The third video shows the initial power up. Like computers, if you remember when equipment was like this, today’s lightweight machines seem like toys. Of course, everything works better these days, so we won’t complain. But there’s something about having a big substantial piece of gear with all the requisite knobs, switches, meters, and everything else.

We can’t wait to see the rest of the restoration and to hear this noble radio on the air again. You can tell that [Daniel] loves this kind of gear and you can pick up a lot of tips and lingo watching the videos.

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Hackaday Podcast 213: Not Your Grandfather’s Grandfather Clock, The Engineering Behind Art, Hydrogen Powered Flight

April 7, 2023 by Tom Nardi 7 Comments

Join Hackaday Editors Elliot Williams and Tom Nardi as they review some of their favorite hacks and projects of the past week. The episode starts with a discussion about the recently announced Artemis II crew, and how their mission compares to the Apollo program of the 1960s and 70s.

From there, the pair theorize as to why Amazon’s family of Echo devices have managed to evade eager hardware hackers, take a look at a very impressive SMD soldering jig created with some fascinating OpenSCAD code, marvel at the intersection of art and electronic design, and wonder aloud where all the cheap motorized satellite dishes are hiding. Stick around for some questionable PCB design ideas, a Raspberry Pi expansion that can read your mind, and the first flight of a (semi) hydrogen-powered aircraft.

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 your own personal copy!

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The 13.5 Million Core Computer

November 23, 2022 by Al Williams 55 Comments

Having a dual- or quad-core CPU is not very exotic these days and CPUs with 12 or even 16 cores aren’t that rare. The Andromeda from Cerebras is a supercomputer with 13.5 million cores. The company claims it is one of the largest AI supercomputers ever built (but not the largest) and can perform 120 Petaflops of “dense compute.”

We aren’t sure about the methodology, but they also claim more than one exaflop of “AI computing.” The computer has a fabric backplane that can handle 96.8 terabits per second between nodes. According to a post on Extreme Tech, the core technology is a 3-plane wafer processor, WSE-2. One plane is for communications, one holds 40 GB of static RAM, and the math plane has 850,000 independent cores and 3.4 million floating point units.

The data is sent to the cores and collected by a bank of 64-core AMD EPYC 3 processors. Andromeda is optimized to handle sparse matrix computations. The company claims that the performance scales “almost linearly.” That is, as you double the number of cores used, you roughly half the total run time.

The machine is available for remote use and cost about $35 million to build. Since it uses 500 kW at peak run times, it isn’t free to operate, either. Extreme Tech notes that the Frontier computer at Oak Ridge National Labs is both larger and more precise, but it cost $600 million, so you’d expect it to be more capable.

Most homebrew “supercomputers” we see are more for learning how to work with clusters than trying to hit this sort of performance. Of course, if you have a modern graphics card, OpenCL and CUDA will let you do some of this, too, but at a much lesser scale.

Hackaday Links: November 13, 2022

November 13, 2022 by Dan Maloney 6 Comments

Talk about playing on hard mode! The news this week was rife with stories about Palmer Luckey’s murder-modified VR headset, which ostensibly kills the wearer if their character dies in-game. The headset appears to have three shaped charges in the visor pointing right at the wearer’s frontal lobe, and would certainly do a dandy job of executing someone. In a blog post that we suspect was written with tongue planted firmly in cheek, Luckey, the co-founder of Oculus, describes that the interface from the helmet to the game is via optical sensors that watch the proceeding on the screen, and fire when a certain frequency of flashing red light is detected. He’s also talking about ways to prevent the removal of the headset once donned, in case someone wants to tickle the dragon’s tail and try to quickly rip off the headset as in-game death approaches. We’re pretty sure this isn’t serious, as Luckey himself suggested that it was more of an office art thing, but you never know what extremes a “three commas” net worth can push someone to.

There’s light at the end of the Raspberry Pi supply chain tunnel, as CEO Eben Upton announced that he foresees the Pi problems resolving completely by this time next year. Upton explains his position in the video embedded in the linked article, which is basically that the lingering effects of the pandemic should resolve themselves over the next few months, leading to normalization of inventory across all Pi models. That obviously has to be viewed with some skepticism; after all, nobody saw the supply chain issues coming in the first place, and there certainly could be another black swan event waiting for us that might cause a repeat performance. But it’s good to hear his optimism, as well as his vision for the future now that we’re at the ten-year anniversary of the first Pi’s release.

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The 1337 PNG Hashquine

September 28, 2022 by Jonathan Bennett 7 Comments

A hashquine is a fun way to show off your crypto-tricks — It’s a file that contains its own hash. In some file types it’s trivial, you just pick the hash to hit, and then put random data in a comment or other invisible field till you get a collision. A Python script that prints its own hash would be easy. But not every file type is so easy. Take PNG for instance. these files are split into chunks of data, and each chunk is both CRC-32 and adler32 checksummed. Make one change, and everything changes, in three places at once. Good luck finding that collision. So how exactly did [David Buchanan] generate that beautiful PNG, which does in fact md5sum to the value in the image? Very cleverly.

Thankfully [David] shared some of his tricks, and they’re pretty neat. The technique he details is a meet-in-the-middle hack, where 36 pairs of MD5 collision blocks are found, with the understanding that these 36 blocks will get added to the file. For each block, either A or B of the pair will get plugged in at that location, and the md5sum won’t change. It’s a total of 2^36 possible combinations of these blocks, which is more computation than was practical for this particular hack. The solution is to pre-compute the results of every possible combination of the first 18 blocks, and store the results in a lookup table. The second half of the collisions are run backwards from a target CRC value, and the result checked against the lookup table. Find a hit, and you just found a series of blocks that matches both your target md5sum and CRC32 results.

Thanks to [Julian] for the tip! And as he described it, this hack is one that gets more impressive the more you think about it. Enjoy!

DIY Fume Extractor With ATtiny13 Speed Control

September 4, 2022 by Tom Nardi 15 Comments

Let’s be honest, commercially-available soldering fume extractors are cheap enough that you probably don’t need to build one yourself. But it still makes for a good starter project, especially if you go out of your way to really flex your maker muscles like [Arnov Sharma] did with this tidy build.

All the hallmarks of modern hardware making are on display here — you’ve got the 3D printed enclosure, a motor salvaged from a cheap toy quadcopter, and a custom PCB which uses the ATtiny13 and an AO4406 MOSFET to implement a PWM speed control.

The first press of the button starts the motor off at max speed, but keep pushing it, and the motor’s speed will ramp down until it turns off entirely. There’s even a TP4056 charge controller to top off the internal 18650 cell when the fume extractor is connected to a USB power source.

Is it over-engineered? Perhaps. But projects like these are a great opportunity to practice your skills, whether it’s PCB design or creating bespoke 3D printed enclosures. In the era of cheap 32-bit microcontrollers, it’s also refreshing to see hackers still dragging the ATtiny from time to time.

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Adding USB-C To An IPhone 13 Is Delicate Work

June 24, 2022 by Lewin Day 4 Comments

USB-C seeks to rule the roost when it comes to connectors, and even has Big Europe on its side. Apple hasn’t had to abandon Lightning just yet, but [Restore Technique] has put a USB-C port into an iPhone 13 to give us all an idea what it’s going to be like in the brave new future ahead of us.

The idea came about after disassembling the iPhone 13, and the project was locked in after seeing the first iPhone with a USB-C connector sell for $86,001 on eBay. The plan had to support fast charging, cable reversibility, and data transfer, without cutting out any functionality or compromising water resistance.

The concept is simple enough: take the C94 board from a Lightning to USB-C cable, and put it inside the phone along with a USB-C port. Of course, actually achieving that is the real challenge. Techniques from melting apart Lightning connectors to carefully peeling apart 0.5 mm pitch flex cables to fit 0.6 mm pitch pads.

It’s an impressive hack, and explained so well it’s actually tempting to try it at home for the sheer challenge of the thing. If you do pull off a similar hack yourself, drop us a line! Video after the break.

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