Category Archives: oscillator

ESP32 Makes for World’s Worst Radio Station

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We can say one thing for [bitluni]: the BOMs for his projects, like this ESP32 AM radio transmitter, are always on the low side. That’s because he leverages software to do jobs traditionally accomplished with hardware, always with instructive results.

In this case, the job at hand is creating an RF oscillator in the broadcast AM band and modulating some audio onto it. From his previous experience using an ESP32 to watch video on an oscilloscope, [bitluni] knew that the microcontroller’s DACs were up to the task of producing an 800-kHz signal, and he managed to produce a more-or-less sine …read more

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Zenith’s New Watch Oscillator is Making Waves

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Swiss watchmaker Zenith has created what many mechanical watch fanatics are calling the biggest improvement to mechanical watch accuracy since the invention of the balance spring in 1675. The Caliber ZO 342 is a new type of harmonic oscillator that runs at 15 Hz, which is almost four times the speed of most watches. The coolest part? It’s fabricated out of silicon using Deep Reactive Ion Etching (DRIE), and it single-handedly replaces about 30 components.

Before explaining how Zenith’s oscillator works and why this is such exciting news, it’s important to understand why the balance spring and balance wheel were …read more

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Tesla Coil uses Vintage Tube

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We’ve seen a fair amount of Tesla coil builds, but ones using vacuum tubes are few and far between. Maybe it’s the lack of availability of high power tubes, or a lack of experience working with them among the younger crop of hackers. [Radu Motisan] built a vacuum tube Tesla coil several years back, and only just managed to tip us off recently. Considering it was his first rodeo with vacuum tubes, he seems to have done pretty well — not only did he get good results, he also managed to learn a lot in the process.

His design is …read more

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Tesla Coil uses Vintage Tube

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We’ve seen a fair amount of Tesla coil builds, but ones using vacuum tubes are few and far between. Maybe it’s the lack of availability of high power tubes, or a lack of experience working with them among the younger crop of hackers. [Radu Motisan] built a vacuum tube Tesla coil several years back, and only just managed to tip us off recently. Considering it was his first rodeo with vacuum tubes, he seems to have done pretty well — not only did he get good results, he also managed to learn a lot in the process.

His design is …read more

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One Transistor RTL-SDR Upconverter

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Even if you haven’t used one, you’ve probably seen the numerous projects with the inexpensive RTL-SDR USB dongle. Originally designed for TV use, the dongle is a software defined radio that many have repurposed for a variety of radio hacking projects. However, there’s one small issue. By default, the device only works down to about 50 MHz or so. There are some hacks to change that, but the cleanest way to get operation is to add an upconverter to shift the frequency you want higher. Sounds complicated? [Qrp-Gaijin] shows how to do it with a single transistor. You can see …read more

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Flash a Light Bulb, Win a Prize

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How many geeks does it take to flash a lightbulb? Judging from the list of entries in the 2017 Flashing Light Prize, so far only seven. But we suspect Hackaday readers can add to that total.

The goal is almost as simple as possible: build something that can flash an incandescent light bulb for at least five minutes. The system actually has to power the bulb’s filament, so no mechanical shutters are allowed. Other than that, the sky is the limit — any voltage, any wattage, any frequency and duty cycle, and any circuit. Some of the obvious circuits, like …read more

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Model Sputnik Finds its Voice After Decades of Silence

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As we approach the 60th anniversary of the human race becoming a spacefaring species, Sputnik nostalgia will no doubt be on the rise. And rightly so — even though Sputnik was remarkably primitive compared to today’s satellites, its 1957 launch was an inflection point in history and a huge achievement for humanity.

The Soviets, understandably proud of their accomplishment, created a series of commemorative models of Earth’s first artificial moon as gifts to other countries. How one came into possession of the Royal Society isn’t clear, but [Fran Blanche] found out about it through a circuitous route detailed in the …read more

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Ham Goes Nuts for Tiny Transmitter

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What’s the minimal BOM for a working amateur radio transmitter? Looks like you can get away with seven parts, or eight if you include the walnut. You’ve got to have a walnut.

Some hams really love the challenge of QRP, or the deliberate use of low-power transmitters to provide a challenge to making long-distance contacts. We’ve covered the world of QRP before and noted that while QRP rigs don’t throw a lot of power, it doesn’t mean that they need to be simple. Some get quite complex and support many different modulation schemes, even digital modes. With only a single …read more

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Using a Lecher Line To Measure High Frequency

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How do you test the oscillator circuit you just made that runs between 200MHz and 380MHz if all you have is a 100MHz oscilloscope, a few multimeters and a DC power supply? One answer is to put away the oscilloscope and use the rest along with a length of wire instead. Form the wire into a Lecher line.

That’s just what I did when I wanted to test my oscillator circuit based around the Mini-Circuits POS-400+ voltage controlled oscillator chip (PDF). I wasn’t going for precision, just verification that the chip works and that my circuit can adjust the frequency. …read more

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Understanding The Quartz Crystal Resonator

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Accurate timing is one of the most basic requirements for so much of the technology we take for granted, yet how many of us pause to consider the component that enables us to have it? The quartz crystal is our go-to standard when we need an affordable, known, and stable clock frequency for our microprocessors and other digital circuits. Perhaps it’s time we took a closer look at it.

The first electronic oscillators at radio frequencies relied on the electrical properties of tuned circuits featuring inductors and capacitors to keep them on-frequency. Tuned circuits are cheap and easy to produce, …read more

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