All Handheld Antennas Are Not Born The Same

November 30, 2025 by No comments

If you own a handheld transceiver of any type then the chances are it will come with a “rubber duck” style antenna. These flexible rubber-coated antennas are a compromise in performance, being significantly smaller than a wavelength at their frequency of operation. [OM40ET] has an interesting video in which he investigates this by tearing down a cheap rubber duck antenna and an even cheaper fake.

These antennas usually have a flexible upper section and a bulge at the bottom over the connector. The fake one has nothing in the bulge except the antenna wire and thus has a very high SWR, while the “real” one has a loading coil. This coil is an interesting design, because it’s designed such that the antenna has two resonant points at the 2 metre and 70 centimetre amateur bands. On paper it’s a tapped coil fed at the tap through a capacitor for matching, but a more detailed appraisal will tell you that the two halves of the coil are designed to return those two resonances. It’s still a not-very-good antenna, but the fact that it works at all is something.

If you want something better at VHF and haven’t got much space, all is not lost. We recently featured a VHF magnetic loop.

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[Piers] explains his code

A Deep Dive Into Using PIO And DMA On The RP2350

November 30, 2025 by No comments

Here’s a fun rabbit hole to run down if you don’t already have the RP2040/RP2350 PIO feather in your cap: how to serve data without CPU intervention using PIO and DMA on the RP2350.

If you don’t know much about the RP2040 or RP2350 here’s the basic run down: the original Raspberry Pi Pico was released in 2021 with the RP2040 at its heart, with the RP2350 making its debut in 2024 with the Pico 2. Both microcontrollers include a feature known as Programmed I/O (PIO), which lets you configure tiny state machines and other facilities (shift registers, scratch registers, FIFO buffers, etc) to process simple I/O logic, freeing up the CPU to do other tasks.

The bottom line is that you can write very simple programs to do very fast and efficient I/O and these programs can run separately to the other code running on your micro. In the video below, [piers] explains how it works and how he’s used it in his One ROM project.

This is the latest installment from [piers rocks] whose One ROM project we’ve been tracking since July this year when we first heard about it. Since then we’ve been watching this project grow up and we were there when it was only implemented on the STM32F4, when it was renamed to One ROM, and when it got its USB stack. Along the way [piers rocks] was on FLOSS Weekly Episode 850: One ROM To Rule Them All too.

Have you seen PIO being put to good use in other projects? Let us know in the comments, or on the tips line!

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Jerry Seinfeld dressed up as a honey bee promoting his film Bee Movie.

Retrotechtacular: The $550K Video Conferencing System Used To Make Bee Movie

November 30, 2025 by 4 Comments

The modern office environment has shifted in recent years. Employees are routinely asked to collaborate with co-workers half way around the globe and be camera ready, or whatever passes for webcam ready, in order to telecommute when they are out of office. Every office laptop, tablet, or cell phone these days comes equipped with some sort of camera sensor capable of recording at HD resolution. Twenty years ago, that was not the case. Though tech conglomerates like HP had a different idea of teleconferencing to sell back in 2005 dubbed the Halo Collaboration Studio.

The Halo Studio was a collaboration between HP and Dreamworks that was used during the production of Bee Movie. Studio heads at Dreamworks thought it necessary to install the HP teleconferencing solution inside the New York office of Jerry Seinfeld, the writer of the film, as to allow him to avoid long trips to Dreamworks production offices in Los Angeles. According to the HP Halo Collaboration Studio brochure, “Halo actually pays for itself, not only by reducing travel costs, but also by encouraging higher productivity and stronger employee loyalty.” Certainly Dreamworks believed in that sales pitch for Bee Movie, because the upfront asking price left a bit of a sting.

Less of a singular machine, more of an entire dedicated room, the Halo Studio had a $550,000 asking price. It utilized three 1280×960 resolution plasma screens each fitted with a 720p broadcast camera and even included an “executive” table for six. The room lighting solution was also part of the package as the intent was to have all participants appear true to life size on the monitors. The system ran on a dedicated T3 fiber optic connection rated at 45 Mbps that connected to the proprietary Halo Video Exchange Network that gave customers access to 24×7 tech support for the small sum of $30,000 a month.

For more Retrotechtacular stories, check out Dan’s post on the Surveyor 1 documentary. It’s out of this world.

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Tiny Little TV Runs On ESP32

November 30, 2025 by 8 Comments

Few of us keep big old cathode ray tubes in the house anymore, but we can still appreciate the form factor of the classic TV. Indeed, the Tinytron from [t0mg] is a neat little tchotchke in this vein — a miniature TV that you could just about fit on a keyring.

[t0mg] wanted this project to be quick and easy to put together. It starts with an ESP32-S3-LCD-1.69 from Waveshare. It’s an all-in-one dev module which combines the microcontroller with a small screen right out of the box. You just have to solder a single six pin header to hook it up with an SD card reader and battery, and you’re done with the electronics. Even the case is a cinch to build, with four 3D printed components that can be spat out of a Prusa MK4S in just half an hour. Programming it can be done via a web browser. Just about the only thing it’s missing is a speaker — this TV is video only.

To watch things on the Tinytron, you just have to prepare them properly and drop them on the SD card. [t0mg] provides a web page for transcoding the video files, although you can do it yourself locally with ffmpeg if you prefer.

If you’re looking for a silly gift for a TV-obsessed friend, you could probably whip up a Tinytron in a couple hours or less. It reminds us of another great project, the tiny Simpsons replica TV that endlessly plays the greatest cartoon on Earth.

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bikes are shown raised from the floor from the garage opener lift

Raise Bikes To The Heavens With Humble Garage Door Opener

November 30, 2025 by 9 Comments

Biking can be an incredibly rewarding hobby, but what do you do with all of your expensive pieces of metal and composite when you aren’t hitting the trails? They take up space that you could use for more bikes! [Chaz] figured there had to be a better way and discovered the unlikely solution of the humble garage opener.

Garage doors are made to lift high with moderate weight, exactly what one would expect from a bike lift. If you have high ceilings in your garage or wherever else you store your bikes there can’t be much easier than pushing a button to get your bike out of the way.

To assemble the unusual bike rack, [Chaz] mounted the motor to the wall with a few scraps of wood, and built a wooden platform that rides along the rail. This additional board allows you to use a traditional bike wheel rack to gently raise the bike. While initially [Chaz] had some questionable results, this was quickly resolved with removing the rotational elements of the mount and allowing a slight slant in the bike.

While not everyone may need to raise their bikes to the heavens, this type of simple hacking is always rewarding to see come together. If you want to see how some more bike specific tech works, check out the insides of this expensive bike seat!

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How To Make Big Cabinets On A Small CNC Router

November 30, 2025 by 13 Comments

It’s easy to build big wooden furniture if you have a massive industrial CNC router, but few of us are so lucky. However, you can still build sizable stuff with a smaller router if you know what you’re doing. [Aribabox] shares some useful tricks and techniques for building large workshop cabinets on smaller machines.

The key to doing this well is modularity. [Aribabox] shows off how to build excellent workshop drawers in pieces using a stackable design. Rather than having to cut out one huge side panel to cover the whole stack of drawers, each drawer can have its own side panel that easily fits on a smaller router. They can then be stacked into a stout assembly that still does its job perfectly well. Assuming your CNC router is trued up properly, you can whip up a lot of furniture quickly, just assembling everything with screws.  You’ll still be able to work faster and make bigger things easier on a big machine, but a small machine can do a lot more than you think.

[Aribabox] supplies design files for a cost if you’re eager to replicate their work. If that doesn’t suit you, you can always just use the video as inspiration to work on your own modular furniture designs instead. We’ve featured other modular furniture designs before, too, that rely on 3D printed and lasercut components.

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Magnus Effect Drone Flies, Looks Impossible

November 30, 2025 by 13 Comments

By now we’re all familiar with the quad-rotor design most popular among modern drones, and of course there are many variants using more or less propellers and even fixed-wing drones that can fly autonomously. We’ve even seen drones that convert from rotorcraft to fixed-wing mid flight. But there are even more esoteric drones out there that are far more experimental and use even more bizarre wing designs that look like they shouldn’t be able to fly at all. Take [Starsistor]’s latest design, which uses a single motor and an unconventional single off-center wing to generate lift.

This wing, though, is not a traditional foil shape typically found on aircraft. It uses the Magnus effect to generate lift. Briefly, the Magnus effect is when lift is generated from a spinning object in a fluid. Unlike other Magnus effect designs which use a motor to spin a cylinder, this one uses a design inspired by Savonius wind turbines where a wing is free to rotate around a shaft. A single propeller provides a rotational force to the craft, allowing this off-center wing to begin spinning and generating lift. The small craft was able to sustain several flights but was limited due to its lack of active control.

[Starsistor] went through a number of iterations before finally getting this unusual craft to fly. His first designs did not have enough rotational inertia and would flip over at speed, which was fixed by moving the propeller further away from the center of the craft. Eventually he was able to get a working design to prove his conceptual aircraft, and we hope to see others from him in the future.

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