The Peak Of Vacuum Tube Radio Design

One of the more popular trends in the ham radio community right now is operating away from the shack. Parks on the Air (POTA) is an excellent way to take a mobile radio off-grid and operate in the beauty of nature, but for those who want to take their rig to more extreme locations there’s another operating award program called Summits on the Air (SOTA) that requires the radio operator to set up a station on a mountaintop instead. This often requires lightweight, low-power radios to keep weight down for the hike, and [Dan] aka [AI6XG] has created a radio from scratch to do just that.

[Dan] is also a vacuum tube and CW (continuous wave/Morse code) operator on top of his interest in summiting various mountains, so this build incorporates all of his interests. Most vacuum tubes take a lot of energy to operate, but he dug up a circuit from 1967 that uses a single tube which can operate from a 12 volt battery instead of needing mains power, thanks to some help from a more modern switch-mode power supply (SMPS). The SMPS took a bit of research, though, in order to find one that wouldn’t interfere with the radio’s operation. That plus a few other modern tweaks like a QCX interface and a switch to toggle between receive to transmit easily allows this radio to be quite versatile when operating while maintaining its portability and durability when summiting.

For those looking to replicate a tube-based radio like this one, [Dan] has made all of the schematics available on his GitHub page. The only other limitation to keep in mind with a build like this is that it tends to only work on a very narrow range of frequencies without adding further complexity to the design, in this case within the CW portion of the 40-meter band. But that’s not really a bad thing as most radios with these design principles tend to work this way. For some other examples, take a look at these antique QRP radios for operating using an absolute minimum of power.

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Hackaday Links: March 7, 2021

It’s March, which means Keysight is back in the business of giving away a ton of test gear. Keysight University Live starts on March 15, with daily events the first week followed by a string of weekly live events through April. We always enjoy these Keysight events; sure, they’re clearly intended to sell more gear, but the demos and tutorials are great, and we always learn a lot. There’s also a feeling of community that feels similar to the Hackaday community; just a bunch of electronics nerds getting together to learn and share. If you’re interested in that community, or even if you’re just looking for a chance to win something from the $300,000 pile of goodies, you’ll need to register.

There’s another event coming up that you’ll want to know about: the 2021 Open Hardware Summit. Because 2021 is the new 2020, the summit is being held virtually again, this year on April 9. Tickets are on sale now, and we’re told there are still plenty of Ada Lovelace Fellowships available to those who consider themselves to be a minority in tech. The Fellowship covers the full cost of a ticket; it usually covers travels costs too, but sadly we’re still not there yet.

Once we do start traveling again, you might need to plan more carefully if cities start following the lead of Petaluma, California and start banning the construction of gas stations. The city, about 40 miles (64 km) north of San Francisco, is believed to be the first city in the United States to ban new gas station construction. The city council’s decision also prevents gas station owners from expanding, reconstructing, or relocating existing gas stations. The idea is to create incentives to move toward non-fossil fuel stations, like electric vehicle charging stations and hydrogen fueling. Time will tell how well that works out.

Go home Roomba — you’re drunk. That could be what Roomba owners are saying after an update semi-bricked certain models of the robotic vacuum cleaners. Owners noted a variety of behaviors, like wandering around in circles, bumping into furniture, and inability to make its way back to base for charging. There’s even a timelapse on reddit of a Roomba flailing about pathetically in a suspiciously large and empty room. The drunken analogy only goes so far, though, since we haven’t seen any reports of a Roomba barfing up the contents of its dust bin. But we’re still holding out hope.

And finally, if you’re not exactly astronaut material but still covet a trip to space, you might luck out courtesy of Japanese billionaire Yusaku Maezawa. He’s offering to pay the way for eight people from around the world on a planned flight to the Moon and back in 2023. Apparently, Maezawa bought up all the seats for the flight back in 2018 with the intention of flying a group of artists to space. His thinking has changed, though, and now he’s opening up the chance to serve as ballast join the crew to pretty much any rando on the planet. Giving away rides on Starship might be a harder sell after this week’s test, but we’re sure he’ll find plenty of takers. And to be honest, we wish the effort well — the age of routine civilian space travel can’t come soon enough for us.

Hackaday Links: March 5, 2017

Statistically, more celebrities died in 2016 than would be expected. 2017 is turning out to be a little better, but we did recently lose the great [Bill Paxton]. Game over, man. Game over. A few years ago, [Benheck] built his own pinball machine. It’s Bill Paxton Pinball. A great build, and worth revisiting, just like another viewing of Aliens and Apollo 13.

Some of the most popular 3D-printable objects are [flowalistik]’s low-poly Pokemon series. They’re great models, even though he missed the most obvious Pokemon. Of [flowalistik]’s low-poly Pokemon models, the Bulbasaur is a crowd favorite. Because this model is constructed from flat planes joined at an angle, it’s possible to make a huge low-poly Bulbasaur on a laser cutter or a CNC router. Go home Bulbasaur, you’re drunk. We are eagerly awaiting details on how this grass and poison-type tank was made.

For the last few months, [Matthew Cremona] has been building a huge bandsaw mill in his backyard. It’s built for cutting logs into lumber, and this thing is massive. He’s been posting build log videos for the last few months, but this week he’s finally gotten to where we want him to be: he’s cutting gigantic logs. In the coming weeks, he’s going to be cutting a maple crotch that’s 60 inches (1.5 meters) across.

It’s still a bit early, but here are the details for the 2017 Open Hardware Summit. It’s October 5th in Downtown Denver. If you want to speak at OHS, here you go. If you want to sponsor OHS, here you go. Tickets are over on Eventbrite.

What happens when you give away a new Raspberry Pi Zero W to the fifth caller? This. In other news, Adafruit somehow acquired a real New York City payphone. I’ve heard they were replacing these with WiFi hotspots, which means there are a ton of payphones in a warehouse somewhere? Can anyone hook us up?