Zenith’s New Watch Oscillator is Making Waves

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

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

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

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

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

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

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

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

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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A Vintage Single Transistor LED Blinker

[Eric Wasatonic] had a box of SWB2433 transistors that he had very little information about. In order to discover their properties, he fired up his curve tracer to compare these transistors with more common ones. He noticed the SWB2433 exhibited negative resistance while the similar curves of a 2n3904 didn’t. Then he reverse-biased the two transistors: the negative resistance region on the 2n3904 was less than that of the SWB2433, but it was there, and a 2n2222 had a bigger region. Using this knowledge, he developed a relaxation oscillator circuit which uses a negatively biased transistor.

Using one transistor, one …read more

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