FLOSS Weekly Episode 779: Errata Prevention Specialist

This week Jonathan Bennett and Dan Lynch sit down with Andy Stewart to talk about Andy’s Ham Radio Linux (AHRL)! It’s the Linux distro designed to give hams the tools they need to work with their radios. What’s it like to run a niche Linux distro? How has Andy managed to keep up with this for over a decade? And what’s the big announcement about the project breaking today?

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M17 Digital Communications Go From Strength To Strength

The world of amateur radio is like many other fields in that there has been a move underway from analogue to digital modes. In fact, amateur radio has often led the way in digital innovation.  There’s a snag, though: many of the digital speech modes are proprietary. To address this along comes the M17 project, an effort to create an open digital communication protocol for radio amateurs. We’ve looked at them more than once in the past few years, and as they’ve come up with several pieces of new hardware it’s time for another peek.

First up is the Remote Radio Unit, described as “a comprehensive, UHF FM/M17 “repeater in a box,” optimally designed for close antenna placement, enhancing signal strength and reliability.” The repeater forms the “other half” of the UHF handheld radio chain and will be crucial to the uptake of the protocol.

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FLOSS Weekly Episode 778: OctoPrint — People Are Amazing At Breaking Things

This week Jonathan Bennett and Katherine Druckman sit down with Gina Häußge to talk OctoPrint! It’s one of our favorite ways to babysit our 3D printers, and the project has come a long way in the last 12 years! It’s a labor of love, primarily led by Gina, who has managed to turn it into a full time job. Listen in to hear that story and more, including how to run an Open Source project without losing your sanity, why plugins are great, and how to avoid adding a special services employee as a co-maintainer!

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Hackaday Links: April 7, 2024

Folks with a bit of knowledge about network security commonly use virtual private networks (VPNs) when out and about. Whether you’re connecting to public WiFi or somebody passes you a questionable Ethernet cable at a hacker con, it’s nice to have a secure endpoint to tunnel all of your traffic. As a secondary bonus, connecting through a VPN can obscure your physical location. It’s that second feature that has a bunch of people jumping on the VPN bandwagon as they try to dodge the recent porn age checks that have gone into effect in a number of states. According to a recent article in PopSci, one particular VPN provider saw a 275% jump in demand on the same day that PornHub cut off access to users in Texas. While the debate over underage users accessing adult content is far outside of our wheelhouse, anything that gets more users connecting to the Internet via encrypted means is arguably a net positive.

If you wanted somebody from the Geek Squad to set up that VPN so you can get back on PornHub to work securely from the local coffee shop, you might be out of luck. Reports have been coming in that Best Buy’s mobile nerd division is seeing sweeping layoffs. Geeks were told to stay home on Tuesday and await a call from corporate, at which point many got the surprising news that they no longer had a job. The /r/GeekSquad subreddit has been a rallying point for staff who got the axe, with the user [jaym026] posting what we assume is an AI-generated inspirational speech from Optimus Prime. Of course, it sucks for anyone to lose their job, especially with the way things are these days. Still, we’re willing to bet almost none of those affected will look back on the day they were let go from an increasingly irrelevant brick-and-mortar electronics store as a low point in their professional careers.

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Hackaday Podcast Episode 265: Behind The Epic SSH Hack, 1980s Cyber Butler, The Story Of Season 7

This week, Editor-in-Chief Elliot Williams and Kristina Panos convened once again to give the lowdown on this week’s best hacks. First up in the news — it’s giga-sunset time for Gigaset IoT devices, which simultaneously became paperweights on March 29th. And all that Flipper Zero panic? It has spread to Australia, but still remains exactly that: panic.

Then it’s on to What’s That Sound. Kristina failed again, although she was in the right neighborhood. Can you get it? Can you figure it out? Can you guess what’s making that sound? If you can, and your number comes up, you get a special Hackaday Podcast t-shirt.

Then it’s on to the hacks, beginning with the terrifying news of an xz backdoor. From there, we marvel at a 1980s ‘butler in a box’ — a voice-activated home automation system — and at the idea of LoRa transmissions without a radio. Finally, we discuss why you don’t want to piss off Trekkies, and whether AI has any place in tech support.

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Download and savor at your leisure.

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FLOSS Weekly Episode 777: Asterisk — Wait, Faxes?

This week Jonathan Bennett and David Ruggles sit down with Joshua Colp to talk about Asterisk! That’s the Open Source phone system software you already interact with without realizing it. It started as a side project to run the phones for Linux Support Services, and it turned out working on phone systems was more fun than supporting Linux. The project grew, and in the years since has landed at Sangoma, where Joshua holds the title of Asterisk Project Lead.

Asterisk is used in call centers, business phone systems, and telecom appliances around the world. But how does it handle faxes, WebRTC, and stopping spam calls? Just kidding on that last one, still an unsolved problem.

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Why Is My 470uF Electrolytic Cap More Like 20uF?

The simple capacitor equivalent circuit taught in school

Inductors are more like a resistor in series with an ideal inductor, resistors can be inductors as well, and well, capacitors aren’t just simply a capacitance in a package. Little with electronics is as plain and simple in reality as basic theory would have you believe. [Tahmid Mahbub] was measuring an electrolytic capacitor with an LCR and noticed it measuring 19 uF despite the device being rated at 470 uF. This was because such parts are usually specified at low frequencies, and at a mere 100 kHz, it was measuring way out of the specification they were expecting. [Tahmid] goes into a fair bit of detail regarding how to model the equivalent circuit of a typical electrolytic capacitor and how to determine with a bit more accuracy what to expect.

An aluminium electrolytic capacitor is more like this

The basic equivalent circuit for a capacitor has a series resistance and inductance, which covers the connecting leads and any internal tabs on the plates. A large-valued parallel resistor models the leakage through the dielectric in series with the ideal capacitance, which is responsible for the capacitor’s self-discharge property. However, this model is still too simple for some use cases. A more interesting model, shown to the left, comprises a ladder of distributed capacitances and associated resistances that result in a progressively longer time-constant component as you move from C1 to C5. This resembles more closely the linear structure of the capacitor, with its rolled-up construction. This model is hard to use in any practical sense due to the need to determine values for the components from a physical part. Still, it is useful to understand why such capacitors perform far worse than you would expect from just a simple equivalent model that looks at the connecting leads and little else.

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