Automatic Position Reporting Over HF Radio

March 27, 2024 by Bryan Cockfield 13 Comments

While most of us carry cell phones that have GPS and other location services, they require a significant amount of infrastructure to be useful. Drive from Washington to Alaska like [Lonney] did a while back, where that infrastructure is essentially nonexistent, and you’ll need to come up with some other solutions to let friends and family know where you are.

A tool called the Automatic Packet Reporting System (APRS) is fairly robust in the very high frequency (VHF) part of the amateur radio spectrum, but this solution still relies on a not-insignificant amount of infrastructure for the limited distances involved with VHF. [Lonney] adapted a few other tools to get APRS up and running in the HF range, letting his friends keep tabs on him even from the most remote locations.

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The Hunt For Alien Radio Signals Began Sooner Than You Think

March 20, 2024 by Lewin Day 20 Comments

Every 26 months, Earth and Mars come tantalizingly close by virtue of their relative orbits. The closest they’ve been in recent memory was a mere 55.7 million kilometers, a proximity not seen in 60,000 years when it happened in 2003.

However, we’ve been playing close attention to Mars for longer than that. All the way back in 1924, astronomers and scientists were contemplating another close fly by from the red planet. With radio then being the hot new technology on the block, the question was raised—should we be listening for transmissions from fellows over on Mars?

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Super-Portable, Tunable VHF Antenna

March 16, 2024 by Bryan Cockfield 6 Comments

Ham radio is having a bit of a resurgence these days, likely due to awards programs like Parks on the Air (POTA) and Summits on the Air (SOTA), which encourage amateur radio operators to head outside and “activate” at various parks and mountaintops. For semi-mobile operations like this, a low-power radio is often used, as well as other portable gear including antennas. In the VHF/UHF world, the J-pole is a commonly used antenna as well, and this roll-up tunable J-pole antenna is among the most versatile we’ve seen.

The antenna uses mostly common household parts which keeps the cost down tremendously. The structure of the antenna is replacement webbing for old lawn chairs, and the conductive elements for the antenna are made out of metallic HVAC tape which is fixed onto the chair webbing after being cut to shape. The only specialized parts needed for this is a 3D printed bracket which not only holds the hookup for the coax cable feeding the antenna, but is also capable of sliding up and down the lower section of the “J” to allow the antenna to be easily tuned.

As long as you have access to a 3D printer, this antenna is exceptionally portable and pretty easy to make as well. Although VHF and UHF aren’t too popular for POTA and SOTA, portable equipment like this for the higher frequency bands is still handy to have around when traveling or operating remotely. With the antenna situation sorted out, a DIY radio that can make use of it might be in order as well.

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Stressless Shortwave Reviewed

March 12, 2024 by Al Williams 17 Comments

[Dan Robinson] picked up a shortwave receiver known as the “stressless” receiver kit. We aren’t sure if the stress is from building a more complicated kit or operating a more complicated receiver. Either way, it is an attractive kit that looks easy to build.

Presumably to reduce stress, the VFO and receiver boards are already built, so assembly is just a few hours connecting large components and boards. As kits go, this is a fairly simple one. We were surprised to read that the supplier says you can’t upgrade the firmware. We, of course, wonder if that’s true.

For technical specs, the receiver is AM only and can operate from 100 kHz to 30 MHz. It uses a double conversion with intermediate frequencies of 21.4 MHz and 455 kHz. There’s a BNC connector on the back, and the radio requires 11 to 15V on the input. Apparently, the frequency generator inside is an SI5351. The sensitivity and selectivity numbers look very good for an AM radio.

We were surprised to see the radio didn’t have provisions for SSB since AM-only makes it not as useful for hams or others interested in non-broadcast transmissions. If we are doing our conversions correctly, the kit is fairly pricey, too, especially considering that it is AM only.

Still, we like that you could easily assemble a nice-looking radio kit. We were interested in hearing it perform, and [Dan’s] video lets us virtually try it out without the effort. We’ve seen the SI5351 on a carrier if you want to roll your own. Come to think of it, we’ve seen several.

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Inside America’s Last Morse Code Station

March 8, 2024 by Al Williams 40 Comments

The Titanic famously (or infamously) used Morse code to call out in distress at the end of its final voyage. Ships at sea and the land-based stations that supported them used Morse code for decades, but with the growing use of satellites, maritime Morse code ended in 1999. With one notable exception. [Saahil Desai] writing in the Atlantic tells the story of America’s last Morse code station, KPH just north of San Francisco.

In fact, KPH did shut down in 1997 as part of the wind down of Morse code in ocean vessels. But some radio enthusiasts, including [Tom Horsfall] and [Richard Dillman], have brought the venerable station back to life. The radio squirrels, as they call themselves, dutifully send news and weather every Saturday to anyone interested in listening. They also exchange radio traffic, primarily with the SS Jeremiah O’Brien, a World War II-era ship parked nearby. N2FQ visited the station and operated the station on video, which you can see below. Or, check out the tour in the second video, below.

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Internet Radio Built In Charming Cassette-Like Form Factor

February 25, 2024 by Lewin Day 20 Comments

You can listen to plenty of broadcast radio these days. There’s a lot of choice too, with stations on AM, FM, and digital broadcasts to boot. However, if you want the broadest possible choice, you want an internet radio. If that’s your bag, why not build a fun one like [indoorgeek’s] latest design?

The build is based around a PCB and 3D-printed components that roughly ape the design of a cassette tape. It even replicates the typical center window of a cassette tape by using a transparent OLED screen, which displays the user interface. In a neat way, the graphics on the display are designed to line up with those on the PCB, which looks excellent.

An ESP32 is the heart of the operation, which is responsible for streaming audio over the Internet via its WiFi connection. It’s powered by a small lithium-polymer battery, and hooked up with a MAX98357 Class D amplifier driven via the chip’s I2S hardware. Audio is played out over a small speaker salvaged from an old smartphone.

While it’s obviously possible to play whatever you like on a smartphone these days, sometimes it’s fun to have simple devices that just do a single job. Plus, we can’t deny this project looks really neat. Video after the break.

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Hackaday Links: February 11, 2024

February 11, 2024 by Dan Maloney 4 Comments

Apple’s Vision Pro augmented reality goggles made a big splash in the news this week, and try as we might to resist the urge to dunk on them, early adopters spotted in the wild are making it way too easy. Granted, we’re not sure how many of these people are actually early adopters as opposed to paid influencers, but there was still quite a bit of silliness to be had, most of it on X/Twitter. We’d love to say that peak idiocy was achieved by those who showed themselves behind the wheels of their Teslas while wearing their goggles, with one aiming for an early adopter perfecta, but alas, most of these stories appear to be at least partially contrived. Some people were spotted doing their best to get themselves killed, others were content to just look foolish, especially since we’ve heard that the virtual keyboard is currently too slow for anything but hunt-and-peck typing, which Casey Niestat seemed to confirm with his field testing. After seeing all this, we’re still unsure why someone would strap $4,000 worth of peripheral-vision-restricting and easily fenced hardware to their heads, but hey — different strokes. And for those of you wondering why these things are so expensive, we’ve got you covered.

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