ham radio

248 Articles

Communicating With Satellites Like It’s 1957

February 3, 2025 by 14 Comments

When the first artificial satellite, Sputnik, was put into orbit around Earth, anyone in the path of the satellite could receive the beeps transmitted by the satellite provided they had some simple radio equipment. Of course, there was no two-way communication with this satellite, and it only lasted a few weeks before its batteries died. Here in the future, though, there are many more satellites in orbit and a few are specifically meant for ham radio operators. And, like the ’50s, it doesn’t take too much specialized equipment to communicate with them, although now that communication can be two-way.

The first step in this guide by [W2PAK] is to know where these satellites are in the sky. The simplest way to do that is to use a smartphone app called GoSatWatch and, when configured for a specific location, shows the satellites currently overhead. After that it’s time to break out the radio gear, which can be surprisingly inexpensive. A dual-band handheld is required since satellite uplink and downlink can be on different bands, and the antenna can be made from simple parts as well as [W2PAK] demonstrates in a separate video. Combined, this can easily be done for less than $100. [W2PAK] also goes over the proper format and etiquette for a satellite contact as well, so a new operator can pick it up quickly.

Using satellites as repeaters opens up a lot of capabilities when compared to terrestrial communications. Especially for operators with entry-level licenses who are restricted to mostly VHF and UHF, it adds a challenge as well as significantly increased range compared to ground-based repeaters and line-of-sight communications. There are plenty of activities around satellites that don’t require a license at all, too, like this project which downloads weather imagery from weather satellites.

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Bouncing Signals Off Of Satellites Other Than The Moon

January 24, 2025 by 8 Comments

The moon is a popular target for ham radio operators to bounce signals since it’s fairly large and follows a predictable path. There are some downsides, though; it’s not always visible from the same point on Earth and is a relatively long way away. Thinking they could trade some distance for size, an amateur radio group from the Netherlands was recently able to use a radio telescope pointed at a geostationary satellite to reflect a signal back down to Earth, using this man-made satellite to complete the path instead of the more common natural one.

While there are plenty of satellites in orbit meant for amateur radio communication (including the International Space Station, although it occasionally does other things too), these all have built-in radio transmitters or repeaters specifically meant for re-transmitting received signals. They’re also generally not in geostationary orbit. So, with a retired radio telescope with a 20-meter dish aimed directly at one of the ones already there, they sent out a signal which bounced off of the physical body of the satellite and then back down where it was received by a station in Switzerland. Of course, the path loss here is fairly extreme as well since the satellite is small compared to the moon and geostationary orbit is a significant distance away, so they used the Q65 mode in WSJT-X which is specifically designed for recovering weak signals.

Don’t break out the tape measure Yagi antenna to try this yourself just yet, though. This path is not quite as reliable as Earth-Moon-Earth for a few reasons the group is not quite sure about yet. Not every satellite they aimed their dish at worked, although they theorize that this might be because of different shapes and sizes of the satellites or that the solar panels were not pointing the correct direction. But they were able to make a few contacts using this method nonetheless, a remarkable achievement they can add to their list which includes receiving a signal from one of the Voyager spacecraft.

No Ham License? Listen Anyway In Your Browser

January 15, 2025 by 53 Comments

Full disclosure: ham radio isn’t for everyone, and there are many different facets to it. What appeals to one person might bore another to death. One area of ham radio that has changed a lot in the last few years is more or less local and typically mobile operation on VHF or UHF. Not long ago, hams used HTs (walky-talkies or handi-talkies) or mobile radios via repeaters to talk to each other and — the golden prize back then — make phone calls from their cars. Cell phones have made that much less interesting, but there is still an active community of operators talking on repeaters. However, the traffic has gone digital, the Internet is involved, and people with inexpensive, low-powered radios can talk to each other across the globe. This is nothing new, of course. However, having digital services means that operators with special interests can congregate in what amounts to radio chat rooms organized by region or topic.

There’s a long history of people listening to ham radio conversations with shortwave radios, SDRs, and scanners. But with so much activity now carried on the Internet, you can listen in using nothing more than your web browser or a phone app. I’ll show you how. If you get interested enough, it is easy enough to get your license. You don’t need any Morse code anymore, and a simple Technician class license in the United States is all you need to get going.

A Quick DMR Primer

There are several digital ham networks around and like real networks, you can have different physical transport layers and then build on top of that. For the purposes of this post, I’m going to focus on DMR (digital mobile radio) on the Brandmeister network which is very large and popular ham network. You won’t need a license nor will you need to sign up for anything as long as you are content to just listen.

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Custom Firmware Adds Capabilities To Handie Talkie

January 3, 2025 by 58 Comments

Although ham radio can be an engaging, rewarding hobby, it does have a certain reputation for being popular among those who would fit in well at gated Florida communities where the preferred mode of transportation is the golf cart. For radio manufacturers this can be a boon, as this group tends to have a lot of money and not demand many new features in their technology. But for those of us who skew a bit younger, there are a few radios with custom firmware available that can add a lot of extra capabilities.

The new firmware is developed by [NicSure] for the Tidradio TD-H3 and TD-H8 models and also includes a browser-based utility for flashing it to the radio without having to install any other utilities. Once installed, users of these handheld radios will get extras like an improved S-meter and detection and display of CTCSS tones for repeater usage. There’s also a programmer available that allows the radio’s memory channels to be programmed easily from a computer and a remote terminal of sorts that allows the radio to be operated from the computer.

One of the latest firmware upgrades also includes a feature called Ultra Graph which is a live display of the activity on a selected frequency viewable on a computer screen. With a radio like this and its upgraded firmware, a lot of the capabilities of radios that sell for hundreds of dollars more can be used on a much more inexpensive handheld. All of this is possible thanks to an on-board USB-C interface which is another feature surprisingly resisted by other manufacturers even just for charging the batteries.

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The World Morse Code Championship

December 17, 2024 by 54 Comments

If you were in Tunisia in October, you might have caught some of the Morse Code championships this year. If you didn’t make it, you could catch the BBC’s documentary about the event, and you might be surprised at some of the details. For example, you probably think sending and receiving Morse code is only for the elderly. Yet the defending champion is 13 years old.

Teams from around the world participated. There was stiff competition from Russia, Japan, Kuwait, and Romania. However, for some reason, Belarus wins “almost every time.” Many Eastern European countries have children’s clubs that teach code. Russia and Belarus have government-sponsored teams.

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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