Category: Hackaday

via HACKADAY: Antennas That You Install With A Spray-Can

With the explosion in cell phones, WiFi, Bluetooth, and other radio technologies, the demand for antennas is increasing. Everything is getting smaller and even wearable, so traditional antennas are less practical than ever. You’ve probably seen PCB antennas on things like ESP8266s, but Drexel University researchers are now studying using titanium carbide — known as […]

via HACKADAY: Direction Finding And Passive Radar With RTL-SDR

To say that the RTL-SDR project revolutionized hacker’s capabilities in the RF spectrum would be something of an understatement. It used to be that the bar, in terms of both knowledge and hardware, was so high that only those truly dedicated were able to explore the radio spectrum. But today anyone with $20 can pick […]

via HACKADAY: The Pre-CRT Oscilloscope

Oscilloscopes are especially magical because they translate the abstract world of electronics into something you can visualize. These days, a scope is likely to use an LCD or another kind of flat electronic display, but the gold standard for many years was the ubiquitous CRT (cathode ray tube). Historically, though, CRTs were not very common […]

via HACKADAY: AI Finds More Space Chatter

Scientists don’t know exactly what fast radio bursts (FRBs) are. What they do know is that they come from a long way away. In fact, one that occurs regularly comes from a galaxy 3 billion light years away. They could form from neutron stars or they could be extraterrestrials phoning home. The other thing is […]

via HACKADAY: Custom Split-Flap Display Is a Unique Way to Show the Weather

There’s little doubt about the charms of a split-flap display. Watching a display build up a clear, legible message by flipping cards can be mesmerizing, whether on a retro clock radio from the 70s or as part of a big arrival and departure display at an airport or train station. But a weather station with a […]

via HACKADAY: 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 […]

via HACKADAY: Op Amps Before Transistors: A 600V Vacuum Tube Monster

Op amps. Often the first thing that many learn about when beginning the journey into analog electronics, they’re used in countless ways in an overwhelmingly large array of circuits. When we think about op amps, images of DIPs and SOICs spring to mind, with an incredibly tiny price tag to boot. We take their abundance […]

via HACKADAY: Memories Of A Mis-Spent Youth: Learnabout Simple Electronics

Early last spring, we featured a book review, as part of our occasional Books You Should Read series. Usually these are seminal tomes, those really useful books that stay with you for life and become well-thumbed, but in this case it was a children’s book. Making a Transistor Radio, by [George Dobbs, G3RJV], was a part of the […]

via HACKADAY: Getting An RF Low-Pass Filter Right

If you are in any way connected with radio, you will have encountered the low pass filter as a means to remove unwanted harmonics from the output of your transmitters. It’s a network of capacitors and inductors usually referred to as a pi-network after the rough resemblance of the schematic to a capital Greek letter […]

via HACKADAY: Radio Antenna Mismatching: VSWR Explained

If you have ever operated any sort of transmitting equipment, you’ve probably heard about matching an antenna to the transmitter and using the right co-ax cable. Having everything match — for example, at 50 or 75 ohms — allows the most power to get to the antenna and out into the airwaves. Even for receiving […]

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