The one-tube radio setup, in front of a PC monitor

Single Tube SDR Is A Delightful Mix Of Old And New

Software Defined Radio (SDR) is the big thing these days, and why not? A single computer can get rid of a room full of boat anchors, and give you better signal discrimination than all but the best kit. Any SDR project needs an RF receiver, and in this project [mircemk] used a single 6J1 vaccum tube to produce an SSB SDR that combines the best of old and new. 

Single-tube radios are a classic hack, and where a lot of hams got started back in the day, but there is a reason more complicated circuits tend to be used. On the other hand, if you can throw a PC worth of signal processing at the output, it looks like you can get a very sensitive and selective single-sideband (SSB) receiver. 

The 6J1 tube is convenient, since it can run on only 6 V (or down to 3.7 as [mircemk] demonstrates). Here it is used as a mixer, with the oscillator signal injected via the screen grid. Aside from that, the simple circuit consists of a receiving coil, a few resistors and a variable capacitor. How well does it work? Quite well, when paired with a PC; you can judge for yourself in the video embedded below.

We’ve featured a lot of [mircemk]’s projects over the years, like this handsome OLED VU meter, or this frequency analyzer with a VFD  and even a virtual pinball cabinet made from scraps, among many others.

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A Flashlight Of Fire And Ice

[Daniel Salião Ferreira] may or may not be a Game of Thrones fan, but he does have a fun demo of the Seebeck effect in the form of a flashlight powered by fire and ice. The basic idea is to use a thermocouple, but — in this case — he uses a Peltier effect cooler.

The Peltier and Seebeck effects are two sides of the same coin: the Peltier effect creates heating and cooling when current flows through a thermoelectric material. In contrast, the Seebeck effect generates a voltage when there is a temperature gradient. While thermocouples do produce voltage this way, they usually have much lower power output and are useless as heat pumps.

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Building A Wireless Motorized Fader For Lighting Control

Motorized faders are very cool, and you can find them in everything from expensive mixing desks to high-end video editing decks. If you want to build your own wireless motorized fader controls for your own projects, you might like this project from [Ian Peterson].

Faders are useful controls, but they’re usually very one-way devices—you set them to what you want, and that’s it. However, motorized faders are a little fancier. You can move them yourself, or they can be moved under the command of other hardware or software—making a control change automatically that is still visible to the human in front of the control panel.

[Ian Peterson] built his OSCillator motorized fader for his work with lighting consoles in theater contexts. Its name references the Open Sound Control (OSC) platform which is commonly used across various lighting consoles. His build relies on an ESP32 to run the show, which communicates with other lighting hardware via WiFi. The microcontroller is responsible for reading the position of the fader and built-in button, and sending the relevant commands to other lighting devices on the network. At the same time, it must also listen to commands from lighting consoles on the network and update the motorized fader’s position in turn if the relevant control it’s mapped to has been changed elsewhere.

If you’re working in theater or film and you’re wanting to control lighting cues wirelessly, a tool like this can really come in handy. We don’t see a lot of motorized faders in DIY projects, but they pop up now and then.

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The supermaterial lattice.

New Supermaterial: As Strong As Steel And As Light As Styrofoam

Today in material science news we have a report from [German Science Guy] about a new supermaterial which is as strong as steel and as light as Styrofoam!

A supermaterial is a type of material that possesses remarkable physical properties, often surpassing traditional materials in strength, conductivity, or other characteristics. Graphene, for example, is considered a supermaterial because it is extremely strong, lightweight, and has excellent electrical conductivity.

This new supermaterial is a carbon nanolattice which has been developed by researchers from Canada and South Korea, and it has remarkably high strength and remarkably low weight. Indeed this new material achieved the compressive strength of carbon steels (180-360 MPa) with the density of Styrofoam (125-215 kg m-3).

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A man aims the LED flashlight into the night sky.

The World’s Longest Range LED Flashlight

[ApprehensiveHawk6178] reports that they have made the world’s longest range LED flashlight! While technically “handheld”, you’re gonna need both hands for this monster. According to the creator, it draws 1.2 kW (20 A @ 60 V) to deliver 100,000 lumens and approximately 20,000,000 candelas.

This spotlight is made from 48 white LEDs, wired in 16S3P configuration, and is powered by a similarly beefy 20S2P battery pack. That 1.2 kW power draw generates a lot of heat which is dissipated with an array of heat sinks and five cooling fans. Total cost was in the order of $2,000 USD.

It can be controlled via Bluetooth, and can run from its batteries for 30 minutes at full power. If you’d like to geek out over the specs click-through and read the discussion, a lot of technical detail is given and there are a bunch of photos showing the internals and assembly.

We’ve seen high-output LED lights with water cooling in the past, and wonder if that might be the next step for this particular build.

Thanks to [kms] for the tip.

Triggering Lightning And Safely Guiding It Using A Drone

Every year lightning strikes cause a lot of damage — with the high-voltage discharges being a major risk to buildings, infrastructure, and the continued existence of squishy bags of mostly salty water. While some ways exist to reduce their impact such as lightning rods, these passive systems can only be deployed in select locations and cannot prevent the build-up of the charge that leads up to the plasma discharge event. But the drone-based system recently tested by Japan’s NTT, the world’s fourth largest telecommunications company, could provide a more proactive solution.

The idea is pretty simple: fly a drone that is protected by a specially designed metal cage close to a thundercloud with a conductive tether leading back to the ground. By providing a very short path to ground, the built-up charge in said cloud will readily discharge into this cage and from there back to the ground.

To test this idea, NTT researchers took commercial drones fitted with such a protective cage and exposed them to artificial lightning. The drones turned out to be fine up to 150 kA which is five times more than natural lightning. Afterwards the full system was tested with a real thunderstorm, during which the drone took a hit and kept flying, although the protective cage partially melted.

Expanding on this experiment, NTT imagines that a system like this could protect cities and sensitive areas, and possibly even use and store the thus captured energy rather than just leading it to ground. While this latter idea would need some seriously effective charging technologies, the idea of proactively discharging thunderclouds is perhaps not so crazy. We would need to see someone run the numbers on the potential effectiveness, of course, but we are all in favor of (safe) lightning experiments like this.

If you’re wondering why channeling lightning away from critical infrastructure is such a big deal, you may want to read up on Apollo 12.

A Bicycle Is Abandonware Now? Clever Hack Rescues Dead Light

A bicycle is perhaps one of the most repairable pieces of equipment one can own — no matter what’s wrong with it, and wherever you are on the planet, you’ll be able to find somebody to fix your bike without too much trouble. Unfortunately as electric bikes become more popular, predatory manufacturers are doing everything they can to turn a bike into a closed machine, only serviceable by them.

That’s bad enough, but it’s even worse if the company happens to go under. As an example, [Fransisco] has a bike built by a company that has since gone bankrupt. He doesn’t name them, but it looks like a VanMoof to us. The bike features a light built into the front of the top tube of the frame, which if you can believe it, can only be operated by the company’s (now nonfunctional) cloud-based app.

The hack is relatively straightforward. The panel for the VanMoof electronics is removed and the works underneath are slid up the tube, leaving the connector to the front light. An off the shelf USB-C Li-Po charger and a small cell take the place of the original parts under a new 3D printed panel with a switch to run the light via a suitable resistor. If it wasn’t for the startling green color of the filament he used, you might not even know it wasn’t original.

We would advise anyone who will listen, that hardware which relies on an app and a cloud service should be avoided at all costs. We know most Hackaday readers will be on the same page as us on this one, but perhaps it’s time for a cycling manifesto to match our automotive one.

Thanks [cheetah_henry] for the tip.