Collaborate Disseminate
That big grandfather clock in the library might be an impressive piece of mechanical ingenuity, and an even better example of fine cabinetry, but we’d expect that the accuracy of …read more Continue reading An Atomic Pendulum Clock Accurate Enough for CERN
The Si5351 is an extremely useful device, containing multiple clock generators with many versatile programming options that go well beyond its original purpose of providing a clock for digital circuitry. …read more Continue reading Finally, Tame The Si5351!
Software defined radio and widespread software-controlled PLL synthesis for RF has been a game changer. Things like the RTL-SDR can be any kind of radio you like on almost any …read more Continue reading Hacking a PIC to Redefine a Microphone’s Transmit Frequency
Here at Hackaday HQ we’re no strangers to vintage game emulation. New versions of old consoles and arcade cabinets frequently make excellent fodder for clever hacks to cram as much functionality as possible into tiny modern microcontrollers. We’ve covered [rossumur]’s hacks before, but the ESP_8-bit is a milestone in comprehensive …read more
At the heart of many amateur radio and other projects lies the VFO, or Variable Frequency Oscillator. Decades ago this would have been a free-running LC tuned circuit, then as technology advanced it was replaced by a digital phase-locked-loop frequency synthesiser and most recently a DDS, or Direct Digital Synthesis …read more
Why would anyone put as much effort into resurrecting a 1970s split-flap clock as [mitxela] did when he built this custom PLL frequency converter? We’re not sure, but we do like the results.
The clock is a recreation of the prop from the classic 1993 film, Groundhog Day, rigged …read more
Continue reading Split Flap Clock Keeps Time Thanks to Custom Frequency Converter
We usually reserve the honor of Fail of the Week for one of us – someone laboring at the bench who just couldn’t get it together, or perhaps someone who came perilously close to winning a Darwin Award. We generally don’t highlight commercial products in FotW, but in the case of this substandard RF signal generator, we’ll make an exception.
We suppose the fail-badge could be pinned on [electronupdate] for this one in a way; after all, he did shell out $200 for the RF Explorer signal generator, which touts coverage from 24 MHz to 6 GHz. But in true …read more
Continue reading Fail of the Week: How Not to Design an RF Signal Generator
The phase locked loop, or PLL, is a real workhorse of circuit design. It is a classic feedback loop where the phase of an oscillator is locked to the phase of a reference signal using an error signal in the same basic way that perhaps a controller would hold a temperature or flow rate in a physical system. That is, a big error will induce a big change and little errors induce little changes until the output is just right. [The Offset Volt] has a few videos on PLLs that will help you understand their basic operation, how they can …read more
In the first part of our series on in-band signaling, we discussed one of the most common and easily recognizable forms of audio control, familiar to anyone who has dialed a phone in the last fifty years – dual-tone multifrequency (DTMF) dialing. Our second installment will look at an in-band signaling method that far fewer people have heard, precisely because it was designed to be sub-audible — coded squelch systems for public service and other radio services.
To review, an in-band signaling system is loosely defined as any system that sends control information along with the main content …read more
There are some things that you think you know quite well because you learned them in your youth and you understand their principles of operation. Then along comes a link in your morning feed that reminds you of the limits of your knowledge, and you realize that there is a whole new level of understanding to be reached.
Take Phase Locked Loops (PLLs) for example. You learn how they work, you use them for frequency synthesis, and you know they can do other things like recover noisy clock lines and do FM demodulation. But then you read [Paul Lutus’] Understanding …read more
