VNAs And Crystals

Oscillators may use crystals as precise tuned circuits. If you have a vector network analyzer (VNA) — or even some basic test equipment — you can use it to learn the parameters of a cry…

Oscillator Needs Fine-Tuning

Since their invention more than a century ago, crystal oscillators have been foundational to electronic design. They allow for precise timekeeping for the clocks in computers as well as on our wris…

Simplest Speaker Oscillator, Now Even Simpler

It never fails. Lay down some kind of superlative — fastest, cheapest, smallest — around this place and someone out there says, “Hold my beer” and gets to work. In this case…

Op-Amp Drag Race Turns Out Poorly For 741

When it was first introduced in 1968, Fairchild’s 741 op-amp made quite a splash. And with good reason; it packed a bunch of components into a compact package, and the applications for it wer…

No Inductors Needed For This Simple, Clean Twin-Tee Oscillator

If there’s one thing that amateur radio operators are passionate about, it’s the search for the perfect sine wave. Oscillators without any harmonics are an important part of spectrum hy…

Back To Basics With A 555 Deep Dive

Many of us could sit down at the bench and whip up a 555 circuit from memory. It’s really not that hard, which is a bit strange considering how flexible the ubiquitous chip is, and how many w…

Altoids Tin Spy Radio Goes Solid State

[Helge Fykse (LA6NCA)] has a type, as they say. At least as far as radios are concerned, he seems to prefer elegant designs that keep the BOM to the minimum needed to get the job done. And Altoids …

Clock Hack Gives DEC Rainbow A New Lease On Life

In retrocomputing circles, it’s often the case that the weirder and rarer the machine, the more likely it is to attract attention. And machines don’t get much weirder than the DEC Rainb…

An LM386 Oscillator Thanks To Tungsten Under Glass

Once ubiquitous, the incandescent light bulb has become something of a lucerna non grata lately. Banned from home lighting, long gone from flashlights, and laughed out of existence by automotive en…

Spy Transceiver Makes Two Tubes Do The Work Of Five

Here at Hackaday, we love following along with projects as they progress. That’s especially true when a project makes a considerable leap in terms of functionality from one version to another…

Two-Tube Spy Transmitter Fits In The Palm Of Your Hand

It’s been a long time since vacuum tubes were cutting-edge technology, but that doesn’t mean they don’t show up around here once in a while. And when they do, we like to feature t…

A Practical Glue Stick Oscillator

A few months ago we brought you some experiments from [Bill Wera, N2CQR], in which he investigated the use of a glue stick as the former for a permeability tuned inductor. His set-up was very much …

Lamp Flashing Module Is Perfect For Automotive Use

Modern cars tend to have quite advanced lighting systems, all integrated under the control of the car’s computer. Back in the day, though, things like brake lights and indicators were all don…

Solar Cells As Art Form

When most of us approach a project, we have a certain problem to solve. 3D printing, microcontrollers, batteries, and all kinds of technologies are usually tools to accomplish some task. This is no…

A No-Calibration Metal Detector

A traditional early project for someone discovering a love for electronics has been for many years a metal detector. This would mean a few transistors back in the day, but today it’s more lik…

Relax And Enjoy This Simple Drone Synthesizer

You’d think that a synthesizer that makes as much noise and sports as many knobs as this one would have more than a dozen transistors on board. Surely the circuit behind the panel is complex,…

DIY Metal Detector Gives You The Mettle To Find Some Medals

Hurricane season is rapidly approaching those of us who live in the northern hemisphere. While that does come with a good deal of stress for any homeowners who live in the potential paths of storms…

The Atari Punk Console, Now With More Vacuum Tubes

Most of us have beheld the sonic glory of an Atari Punk Console, that lo-fi synth whose classic incarnation is a pair of 555 timers set up to warble and bleep in interesting ways. Very few of us, h…