Author: Dan Maloney

3368 Articles

S15351 tube transmitter

Retro And New Tech Combine In This Hybrid Ham Transmitter

February 27, 2022 by 9 Comments

We’ve said it before and we’ll say it again: the best part about holding an amateur radio license is that it lets you build and use your own transmitting equipment. Hams have been doing this for more than a century — indeed, it was once the only way to get on the air — using whatever technology was available. But the mix of technologies in this low-power transmitter for the 80-meter band is something you don’t see every day.

As ham [Helge Fykse (LA6NCA)] describes in the video below, the project began when he came into possession of a bonanza of vacuum tubes — 12A6 tetrodes, specifically. The new-old-stock tubes were perfect for an RF power amplifier, but that left the problem of what to use for an oscillator. [Helge] chose to meld the old with the new and used oscillator board that he designed. The board has an ATmega88 microcontroller and an Si5351 oscillator, along with a 3V3 regulator to let the module run on 12 volts. And for a nice retro touch, [Helge] put the board in a 3D printed case that looks like an old-fashioned quartz crystal.

There are some other nice design touches here too. A low-pass filter cleans up the harmonics of the oscillator’s 3.5-MHz square wave output before feeding it to the amplifier, in a nod to proper spectrum hygiene. The primary for the amp’s air-core output transformer is hand-wound, with 3D printed spacers to keep the winding neat and even. The tuning process shown below is interesting, and the transmitter was used to make a solid contact with another ham about 100 km away. And we really liked the look of [Helge]’s shack, stuffed as it is with gear both old and new.

We’ve personally tried the Si5351 for QRP transmitters before, but this blend of the old and new really makes us want to find some tubes and get to playing.

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Wordle bot

Solving Wordle By Adding Machine Vision To A 3D Printer

February 26, 2022 by 19 Comments

Truth be told, we haven’t jumped on the Wordle bandwagon yet, mainly because we don’t need to be provided with yet another diversion — we’re more than capable of finding our own rabbit holes to fall down, thank you very much. But the word puzzle does look intriguing, and since the rules and the interface are pretty simple, it’s no wonder we’ve seen a few efforts like this automated Wordle solver crop up lately.

The goal of Wordle is to find a specific five-letter, more-or-less-common English word in as few guesses as possible. Clues are given at each turn in the form of color-coding the letters to indicate whether they appear in the word and in what order. [iamflimflam1]’s approach was to attach a Raspberry Pi camera over the bed of a 3D printer and attach a phone stylus in place of the print head. A phone running Wordle is placed on the printer bed, and Open CV is used to find both the screen of the phone, as well as the position of the phone on the printer bed. From there, the robot uses the stylus to enter an opening word, analyzes the colors of the boxes, and narrows in on a solution.

The video below shows the bot in use, and source code is available if you want to try it yourself. If you need a deeper dive into Wordle solving algorithms, and indeed other variant puzzles in the *dle space, check out this recent article on reverse engineering the popular game.

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Big Chemistry: From Gasoline To Wintergreen

February 22, 2022 by 18 Comments

Most of us probably have some vivid memories of high school or college chemistry lab, where the principles of the science were demonstrated, and where we all got at least a little practice in experimental methods. Measuring, diluting, precipitating, titrating, all generally conducted under safe conditions using stuff that wasn’t likely to blow up or burn.

But dropwise additions and reaction volumes measured in milliliters are not the stuff upon which to build a global economy that feeds, clothes, and provides for eight billion people. For chemistry to go beyond the lab, it needs to be scaled up, often to a point that’s hard to conceptualize. Big chemistry and big engineering go hand in hand, delivering processes that transform the simplest, most abundant substances into the things that, for better or worse, make life possible.

To get a better idea of how big chemistry does that, we’re going to take a look at one simple molecule that we’ve probably all used at one time or another: the common artificial flavoring wintergreen. It’s an innocuous ingredient in a wide range of foods and medicines, but the infrastructure required to make it and all its precursors is a snapshot of just how important big chemistry really is.

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Hackaday Links Column Banner

Hackaday Links: February 20, 2022

February 20, 2022 by 23 Comments

Sounds like somebody had a really bad day at work, as Western Digital reports that “factory contamination” caused a batch of flash memory chips to be spoiled. How much, you ask? Oh, only about 7 billion gigabytes! For those of you fond of SI prefixes, that’s 7 exabytes of storage; to put that into perspective, it’s seven times what Google used for Gmail storage in 2012, and enough to store approximately 1.69 trillion copies of Project Gutenberg’s ASCII King James Version Bible. Very few details were available other than the unspecified contamination of two factories, but this stands poised to cause problems with everything from flash drives to phones to SSDs, and will probably only worsen the ongoing chip shortage. And while we hate to be cynical, it’ll probably be prudent to watch out for any “too good to be true” deals on memory that pop up on eBay and Ali in the coming months.

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Sound And Light Play Off Acrylic And Wire In This Engaging Circuit Sculpture

February 18, 2022 by 3 Comments

It’s no secret that we really like circuit sculptures around here, and we never tire of seeing what creative ways people come up with to celebrate the components used to make a project, rather than locking them away in an enclosure. And a circuit sculpture that incorporates sound and light in its design is always a real treat to discover.

Called “cwymriad” by its designer, [Eirik Brandal], this sound sculpture incorporates all kinds of beautiful elements. The framework is made from thick pieces of acrylic, set at interesting angles to each other and in contrasting colors. The sound-generating circuit, which uses square wave outputs from an ESP32 to provide carrier and modulation signals for a dual ring modulator, is built on a framework of tinned wires. The sounds the sculpture makes have a lovely resonance to them, like random bells and chimes that fade and mix together. There’s also a matrix of white LEDs that form a sort of digital oscilloscope that displays shifting waveforms in time with the music.

While we like the way this looks and sounds, the real bonus here is the details of construction in the video below. [Eirik]’s careful craftsmanship working with multiple materials is evident throughout; we were especially impressed by the work needed to drill holes for the LED matrix, any one of which slightly out of place would have been painfully obvious in the finished product.

This is far from [Eirik]’s first appearance on these pages. His vacuum tube and silicon “ioalieia” was featured just a few weeks back, and “ddrysfeöd” used the acrylic parts as light pipes in a lovely way.

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akurobatto clock

Unique Clock Is All Hands, No Dial, And Does The Worm

February 17, 2022 by 12 Comments

Back in the old days, we didn’t have fancy digital clocks. No, we had good analog clocks with a big hand and a little hand, and if you wanted to know the time you had to look at the clock and figure out which number each hand was pointing at, or kind of pointing at. It wasn’t easy, and we liked it that way.

So now, along comes an analog clock that’s nothing but the hands — no dial, no numbers, just hands. How is such a thing possible? The clue is in the clock’s name: AKUROBATTO, and in the video below, which shows the acrobatic movements of the clock’s hands as it does its thing. Serial improbable-clock maker [ekaggrat singh kalsi] clearly put a lot of thought into this mechanism, which consists of the hands and a separate base. The hands are joined together at one end and powered by small stepper motors. The base has two docking areas, where servo-driven claws can grasp the hand assembly, either at the center pivot or at the tip of either hand. With a little bit of shuffling around at transition points, the hands sweep out the hours and minutes in a surprisingly readable way.

For as cool as the design of AKUROBATTO is, the internals are really something else. There are custom-built slip rings to send power to the motors and the Arduinos controlling them, sensors to determine the position of each hand, and custom gearboxes for the steppers. And the locking mechanisms on the base are worth studying too — getting that right couldn’t have been easy.

All in all, an impressive build. Whether displaying the time on a phosphorescent screen or a field of sequins, it seems like [ekaggrat] has a thing for unique clocks. Continue reading “Unique Clock Is All Hands, No Dial, And Does The Worm” →

Filament Dry Box Design Goes Way Over The Top

February 15, 2022 by 36 Comments

There’s a fine line between simple feature creep and going over the top when it comes to project design. It’s hard to say exactly where that line is, but we’re pretty sure that this filament dry box has at least stepped over it, and might even have erased it entirely.

Sure, we all know the value of storing 3D printer filament under controlled conditions, to prevent the hygroscopic plastics from picking up atmospheric moisture. But [Sasa Karanovic] must really, REALLY hate the printing artifacts that result. Starting with a commercially available dry box that already had a built-in heating element, [Sasa] took it to the next level by replacing the controller and display with an ESP32. He added a fan to improve air circulation inside the enclosure and prevent stratification, as well as temperature and humidity sensors. Not satisfied with simply switching the heating element on and off at specific setpoints, he also implemented a PID loop to maintain a constant temperature. And of course, there’s a web UI and an API available for third-party control and monitoring.

The video below details [Sasa]’s design thoughts and goes into some detail on construction and performance. And while we may kid that this design is over-the-top, what really comes through is that this is a showcase for design ideas not only for one application, but for hardware projects in general. There are certainly simpler heated dry box designs, and zero-cost solutions as well, but sometimes going overboard has its own value too.

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