Category Archives: radio

How To Evolve A Radio

Evolutionary algorithms are an interesting topic of study. Rather then relying on human ingenuity and investigation to create new designs, instead, an algorithm is given a target to achieve, and creates “offspring”, iterating in an evolutionary manner to create offspring that get closer to the target with each generation.

This method can be applied to the design of electronic circuits, and is sometimes referred to as “hardware evolution”. A team from Duke University attempted exactly this, aiming to produce an oscillator using evolutionary techniques.

The team used a platform called the “evolvable motherboard”, or EM. The EM is a platform …read more

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Posted in classic hacks, evolutionary algorithm, radio | Leave a comment

Short Length of Wire Turns STM32 Microcontroller into Good-enough Wireless UART Blaster

Hackaday regular [befinitiv] wrote into the tip line to let us know about a hack you might enjoy, wireless UART output from a bare STM32 microcontroller. Desiring the full printf debugging experience, but constrained both by available space and expense, [befinitiv] was inspired to improvise by a similar hack that used the STM32 to send Morse code over standard FM frequencies.

In this case, [befinitiv]’s solution is both more useful and slightly more legal, as the software uses the 27 MHz ISM band to blast out ASK modulated serial data through a simple wire antenna attached to one of the …read more

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Posted in arm, gnu radio, Microcontrollers, radio, radio hacks, stm32, wireless | Leave a comment

DIY Tuning Capacitors from Washers and 3D-Printed Parts

The inside of classic radios holds wonders that the sterile chips and SMD components of today’s circuits can’t hold a candle to. Chunky resistors and capacitors, vacuum tubes with cathodes aglow, and seemingly free-form loops of wire forming inductors will all likely make an appearance. But the most fascinating bit of any old radio was connected to the tuning knob: the big variable capacitor with its interdigitating metal plates. Watching one at work, with its plates evenly and finely spaced, is still a joy to behold.

In an attempt to recapture a little of that magic, [Jeremy S. Cook] came …read more

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Posted in capacitor, classic hacks, home brew, plate, radio, tuning capacitor, variable capacitor, washer, wiper, wireless hacks | Leave a comment

Studying Airplane Radio Reflections With SDR

A property of radio waves is that they tend to reflect off things. Metal surfaces in particular act as good reflectors, and by studying how these reflections work, it’s possible to achieve all manner of interesting feats. [destevez] decided to have some fun with reflections from local air traffic, and was kind enough to share the results.

The project centers around receiving 2.3 GHz signals from a local ham beacon that have been reflected by planes taking off from the Madrid-Barajas airport. The beacon was installed by a local ham, and transmits a CW idenfication and tone at 2 W …read more

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Posted in radio, radio hacks, radio reflection, radio reflections, reflection, reflections, sdr | Leave a comment

Help For High-Frequency Hobbyists

Dead-bug circuit building is not a pretty affair, but hey, function over form. We usually make them because we don’t have a copper circuit board available or the duty of making one at home is not worth the efforts and chemical stains.

[Robert Melville and Alaina G. Levine] bring to light a compromise for high-frequency prototypes which uses the typical FR4 blank circuit board, but no etching chemicals. The problem with high-frequency radio is that building a circuit on a breadboard will not work because there is too much added inductance and capacitance from the wiring that will wreak havoc …read more

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Posted in dead bug, deadbug, freq, frequency, high frequency, homemade, radio, radio hacks | Leave a comment

Submarine to Plane: Can You Hear Me Now? The Hydrophone Radar Connection

How does a submarine talk to an airplane? It sounds like a bad joke but it’s actually a difficult engineering challenge.

Traditionally the submarine must surface or get shallow enough to deploy a communication buoy. That communication buoy uses the same type of radio technology as planes. But submarines often rely on acoustic transmissions via hydrophones which is fancy-talk for putting speakers and microphones in the water as transmitters and receivers. This is because water is no friend to radio signals, especially high frequencies. MIT is developing a system which bridges this watery gap and it relies on acoustic transmissions …read more

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Posted in communication, millimeter, radar, radio, radio hacks, sonar, sound, sound wave, translation, waves | Leave a comment

Touch Anything And Everything

Powering IoT devices is often a question of batteries or mains power, but in rare exceptions to this rule there is no power supply (PDF Warning). At the University of Wisconsin-Madison and the University of California, San Diego, researchers have gone the extra mile to make advanced backscatter devices, and these new tags don’t need the discrete components we have seen in previous versions. They are calling it LiveTag, and it doesn’t need anything aside from a layer of foil printed or etched on a flexible ceramic-PTEF laminate. PTEF is mostly seen in the RF sector as a substrate for …read more

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Posted in backscatter, copper, interface, pcb, radio, research, touch, university, wifi, wireless, wireless hacks | Leave a comment

Cross-Correlation Makes Quick Work Of Ads

Once relegated to the proverbial Linux loving Firefox user, ad blocking has moved into public view among increased awareness of privacy and the mechanisms of advertising on the internet. At the annual family gathering, when That Relative asks how to setup their new laptop, we struggle through a dissertation on the value of ad blockers and convince them to install one. But what about mediums besides the internet? Decades ago Tivo gave us one button to jump through recorded TV. How about the radio? If available, satellite radio may be free of The Hated Advertisement. But terrestrial radio and online …read more

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Posted in audio, digital audio hacks, fm radio, home entertainment hacks, radio, Raspberry Pi, receiver | Leave a comment

What Will You Do If WWVB Goes Silent?

Buried on page 25 of the 2019 budget proposal for the National Institute of Standards and Technology (NIST), under the heading “Fundamental Measurement, Quantum Science, and Measurement Dissemination”, there’s a short entry that has caused plenty of debate and even a fair deal of anger among those in the amateur radio scene:

NIST will discontinue the dissemination of the U.S. time and frequency via the NIST radio stations in Hawaii and Ft. Collins, CO. These radio stations transmit signals that are used to synchronize consumer electronic products like wall clocks, clock radios, and wristwatches, and may be used in other

…read more

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Posted in clock hacks, nist, radio, radio hacks, time, wwvb | Leave a comment

Rewinding Live Radio

Even though it’s now a forgotten afterthought in the history of broadcasting technology, we often forget how innovative the TiVo was. All this set-top box did was connect a hard drive to a cable box, but the power was incredible: you could pause live TV. You could record shows. You could rewind TV. It was an incredible capability, that no one had ever seen before. Of course, between Amazon and Netflix and YouTube, no one watches TV anymore, and all those platforms have a pause button, but the TiVO was awesome.

There is one bit of broadcasting that still exists. …read more

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Posted in digital audio hacks, fpga, radio, radio hacks, The Hackaday Prize, TiVo | Leave a comment