Radio Hacks

1376 Articles

Wago Terminals Make This Ham Radio Dipole Light And Packable

December 15, 2024 by 13 Comments

For the amateur radio operator with that on-the-go lifestyle, nothing is more important than having your gear as light and packable as possible. If you’re lugging even a modest setup out into the woods, every ounce counts, which is why we love projects like this packable dipole antenna feedpoint.

At its simplest, a dipole antenna is just two pieces of wire cut to a specific, frequency-dependent length connected to a feedline. In practical terms, though, complications arise, such as keeping common-mode currents off the feedline and providing sturdy mechanical support for the antenna to suspend it safely. [Ham Radio Dude]’s design handles both those requirements while staying as small and packable as possible. The design starts with a bifilar 1:1 current balun, which is wound on an FT82-43 ferrite toroid with 22 AWG magnet wire. One side of the balun is connected to a BNC connector while the other is connected to a pair of Wago splice connectors that are glued together. A loop of paracord for mechanical strain relief is added, and the whole thing gets covered in heat-shrink tubing. The antenna is deployed by attaching a feedline to the BNC, clipping quarter-wave wires into the Wago terminals, and hoisting the whole thing aloft. Full build details are in the video below.

People will no doubt be quick to point out that these Wago terminals are rated for a minimum of 18 AWG wire, making them inappropriate for use with fine magnet wire. True enough, but [Dude] was able to get continuity through the Wagos, so the minimum gauge is probably more of an electrical code thing. Still, you’ll want to be careful that the connections stay solid, and it might pay to look at alternatives to the Wago brand, too. Continue reading “Wago Terminals Make This Ham Radio Dipole Light And Packable” →

Might Morphin’ Antenna

December 14, 2024 by 9 Comments

The shape of an antenna can make a big difference in its performance. Researchers at the Johns Hopkins Applied Physics Laboratory have used shape memory alloy to construct an antenna that changes shape depending on the signals it is receiving. Nitinol, a common shape memory alloy made from nickel and titanium, is an obvious choice, but it’s not obvious how you’d make a shape-changing antenna out of nitinol wire. That changed when a mechanical engineer found a way to 3D print the substance. You can find a paper about the research online from Applied Engineering Materials.

In practice, the antenna is a double spiral made of nitinol. A channel contains a copper wire that can heat the antenna and, therefore, change its shape. Having a powered wire in the antenna can cause problems, so special designs route the signal away from the heating element. It looks like the antenna can assume a flat configuration or a spiral conic configuration.

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Use Your RTL, In The Browser

December 13, 2024 by 14 Comments

The web browser started life as a relatively simple hypertext reading application, but over the 30+ years since the first one displayed a simple CERN web page it has been extended to become the universal platform. It’s now powerful enough to run demanding applications, for example a full software-defined radio. [Jtarrio] proves this, with an application to use an RTL-SDR, in HTML5.

It’s a fork of a previous Google-Chrome-only FM receiver, using the HTML5 WebUSB API, and converted to TypeScript. You can try it out for yourself if you have a handy RTL dongle lying around, it provides an interface similar to the RTL apps you may be used to.

The Realtek digital TV chipset has been used as an SDR for well over a decade now, so we’re guessing most of you with an interest in radio will have one somewhere. The cheap ones are noisy and full of spurious peaks, but even so, they’re a bucket of fun. Now all that’s needed is the transmit equivalent using a cheap VGA adapter, and the whole radio equation could move into the browser.

It’s Remotely Ham Radio

December 11, 2024 by 32 Comments

Have you ever considered running your ham radio remotely? It has been feasible for years but not always easy. Recently, I realized that most of the pieces you need to get on the air remotely are commonplace, so I decided to take the plunge. I won’t give step-by-step instructions because your radio, computer setup, and goals are probably different from mine. But I will give you a general outline of what you can do.

I’m fortunate enough to have a sizeable freestanding shop in my backyard. When I had it built, I thought it was huge. Now, not so much. The little space is crammed with test equipment, soldering gear, laser cutters, drill presses, and 3D printers. I’ve been a ham for decades, but I didn’t have room for the radios, nor did I have an antenna up. But a few months ago, I made space, set some radios up, strung out a piece of wire, and got back on the air. I had so much fun I decided it was time to buy a new radio. But I didn’t want to have to go out to the shop (or the lab, as I like to call it) just to relax with some radio time.

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Amateur Radio Operators Detect Signals From Voyager 1

December 11, 2024 by 41 Comments

At the time of its construction in the 1950s, the Dwingeloo Radio Observatory was the largest rotatable telescope in the world with a dish diameter of 25 meters. It was quickly overtaken in the rankings but was used by astronomers for decades until it slowly fell into disuse in the early 2000s. After a restoration project the telescope is now a national heritage site in the Netherlands where it is also available for use by radio amateurs. Recently this group was able to receive signals from Voyager 1.

Famously, Voyager 1 is the furthest manmade object from Earth, having been launched on a trajectory out of the solar system in 1977. As a result of distance and age, the signals it sends out are incredibly faint. The team first had to mount a new antenna to the dish, which was not originally designed for signals in this frequency which added to the challenge. They then needed to use orbital predictions of the spacecraft in order to target the telescope and also make the correct adjustments to the received signal given that there is significant Doppler shift now as well. But with that all out of the way, the team was successfully able to receive the Voyager 1 signal on this telescope.

Only a few telescopes in the world have ever been able to accomplish this feat, making it all the more impressive. Normally Voyager 1 is received using the Deep Space Network, a fleet of much larger dishes stationed around the world and designed for these frequencies. But this team is used to taking on unique challenges. They also decoded the first ham radio station on the moon and made a radar image of the moon using LoRa.

Dwingeloo telescope receives signals from Voyager 1

Antenna Measurement In Theory And Practice

December 6, 2024 by 9 Comments

If you want to analyze an antenna, you can use simulation software or you can build an antenna and make measurements. [All Electroncs Channel] does both and show you how you can do it, too, in the video below.

The antenna in question is a loop antenna. He uses a professional VNA (Vector Network Analyzer) but you could get away with a hobby-grade VNA, too. The software for simulation is 4NEC2.

The VNA shows the electrical characteristics of the antenna, which is one of the things you can pull from the simulation software. You can also get a lot of other information. You’d need to use a field strength meter or something similar to get some of the other information in the real world.

The antenna simulation software is a powerful engine and 4NEC2 gives you an easy way to use it with a GUI. You can see all the graphs and plots easily, too. Unfortunately, it is Windows software, but we hear it will run under Wine.

The practical measurement is a little different from the simulation, often because the simulation is perfect and the real antenna has non-ideal elements. [Grégory] points out that changing simulation parameters is a great way to develop intuition about — in this case — antennas.

Want to dive into antennas? We can help with that. Or, you can start with a simple explanation.

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LongChat For Ham Radio

December 4, 2024 by 38 Comments

There was a time when ham radio operators were known for having long conversations over the radio — rag chewing, as they called it. A new program, LongChat, is a new entry into the ham radio software world that could bring chatting back to ham radio. [Tech Minds] has a video covering it (and using it), which you can see below.

While some people do talk using microphones or Morse code keys, there are a lot of digital modes now. Some, like RTTY or PSK31, can support conversations, but the more popular ones, like FT-8, are very stripped down. Your computer exchanges basic information with the other station’s computer, and that’s it.

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