A Soviet Cassette Recorder Receiving Some Love

July 29, 2024 by Jenny List 40 Comments

For those of us who lived in the capitalist west during the Cold War, there remains a fascination to this day about the Other Side. The propaganda we were fed as kids matched theirs in describing the awful things on the other side of the wall, something that wasn’t borne out when a decade or so later in the 1990s we met people from the former communist side and found them unsurprisingly to be just like us. It’s thus still of interest to have a little peek into Eastern Bloc consumer electronics, something we have the chance of courtesy of [DiodeGoneWild], who’s fixing a 1980s Soviet cassette recorder.

The model in question is a Vesna 309, and it has some audio issues and doesn’t turn the tape. It gets a teardown, the motor is cleaned up inside, and a few capacitor and pot cleanups later it’s working again. But the interest lies as much in the machine itself as it does in the repair, as it’s instructive to compare with a Western machine of the same period.

We’re told it would have been an extremely expensive purchase for a Soviet citizen, and in some ways such as the adjustable level control it’s better-specified than many of our equivalents. It’s based upon up-to-date components for its era, but the surprise comes in how comparatively well engineered it is. A Western cassette deck mechanism would have been a much more sketchy affair than the substantial Soviet one, and its motor would have been a DC part with a simple analogue speed controller rather than the brushless 3-phase unit in the Vesna. Either we’re looking at the cassette deck for senior comrades only, or the propaganda was wrong — at least about their cassette decks. The full video is below, and if you’re hungry for more it’s not the first time we’ve peered into electronics from the eastern side of the Iron Curtain.

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An Antenna To Throw You For A Loop

July 29, 2024 by Al Williams 27 Comments

It is one of Murphy’s laws, we think, that you can’t get great things when you need them. Back in the heyday of shortwave broadcasting, any of us would have given a week’s pay for even a low-end receiver today. Digital display? Memory? Digital filtering? These days, you have radios, and they aren’t terribly expensive, but there isn’t much to listen to. Making matters worse, it isn’t easy these days to string wires around in your neighborhood for a variety of reasons. Maybe you don’t have a yard, or you have deed restrictions, or your yard lacks suitable space or locations. This problem is so common that there are a crop of indoor antennas that seem attractive. Since I don’t often tune in shortwave and I don’t want to have to reset my antenna after every storm, I decided to look at the Tecsun AN-48X along with a YouLoop clone from China. Let’s start with the Tecsun. Continue reading “An Antenna To Throw You For A Loop” →

A Look At The Intel N100 Radxa X4 SBC

July 29, 2024 by Maya Posch 19 Comments

Recently Radxa released the X4, which is an SBC containing not only an N100 x86_64 SoC but also an RP2040 MCU connected to a Raspberry Pi-style double pin header. The Intel N100 is one of a range of Alder Lake-N SoCs which are based on a highly optimized version of the Skylake core, first released in 2015. These cores are also used as ‘efficiency’ cores in Intel’s desktop CPUs. Being x86-based, this means that the Radxa X4 can run any Linux, Windows and other OS from either NVMe (PCIe 3.0 x4) or eMMC storage. After getting his hands on one of these SBCs, [Bret] couldn’t wait to take a gander at what it can do.

Installing Windows 11 and Debian 12 on a 500 GB NVMe (2230) SSD installed on the X4 board worked pretty much as expected on an x86 system, with just some missing drivers for the onboard Intel 2.5 Gbit Ethernet and WiFi, depending on the OS, but these were easily obtained via the Intel site and installed. The board comes with an installed RTC battery and a full-featured AMI BIOS, as well as up to 16 GB of LPPDR5 RAM.

Using the system with the Radxa PoE+ HAT via the 2.5 Gbit Ethernet port also worked a treat once using a quality PoE switch, even with the N100’s power level set to 15 Watt from the default 6. The RP2040 MCU on the mainboard is connected to the SoC using both USB 2.0 and UART, according to the board schematic. This means that from the N100 all of the Raspberry Pi-style pins can be accessed, making it in many ways a more functional SBC than the Raspberry Pi 5, with a similar power envelope and cost picture.

At $80 USD before shipping for the 8 GB (no eMMC) version that [Bret] looked at one might ask whether an N100-based MiniPC could be competitive, albeit that features like PoE+ and integrated RPi-compatible header are definite selling points.

Making USB Blaster Clones Work For Linux

July 29, 2024 by Al Williams 4 Comments

The last time we checked in with [Downtown Doug Brown], he had some cheap Altera USB Blaster clones that didn’t want to work under Linux. The trick at that time was to change the device’s 24 MHz clock to 12 MHz. This month, he’s found some different ones that don’t work, but now the clock change doesn’t work. What’s the problem?

He also picked up a Terasic clone, which does work on Linux and is considered, according to [Doug], the best of the clones. The units were superficially similar. So what follows is a lot of USB tracing and dumping of the CPLD chip’s configuration.

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The BiVACOR Total Artificial Heart: A Maglev Bridge To Life

July 28, 2024 by Maya Posch 28 Comments

The BiVACOR THA hooked up with the CTO Dianiel Timms in the background. (Credit: BiVACOR)

Outside of the brain, the heart is probably the organ that you miss the most when it ceases to function correctly. Unfortunately, as we cannot grow custom replacement hearts yet, we have to keep heart patients alive long enough for them to receive a donor heart. Yet despite the heart being essentially a blood pump, engineering even a short-term artificial replacement has been a struggle for many decades. A new contender has now arrived in the BiVACOR TAH (total artificial heart), which just had the first prototype implanted in a human patient.

Unlike the typical membrane-based pumps, the BiVACOR TAH is a rotary pump that uses an impeller-based design with magnetic levitation replacing bearings and theoretically minimizing damage to the blood. This design should also mean a significant flowrate, enough even for an exercising adult. Naturally, this TAH is only being tested as a bridge-to-transplant solution, for patients with a failing heart who do not qualify for a ventricular assist device. This may give more heart patients a chance to that donor heart transplant, even if a TAH as a destination therapy could save so many more lives.

The harsh reality is that the number of donor hearts decreases each year while demand increases, leading to unconventional approaches like xenotransplantation using specially bred pigs as donor, as well as therapeutic cloning to grow a new heart from the patient’s own cells. Having a universal TAH that could be left in-place (destination therapy) for decades would offer a solid option next to the latter, but remains elusive. As shown by e.g. the lack of progress with a TAH like the ReinHeart despite a promising 2014 paper in a bovine model.

Hopefully before long we’ll figure out a reliable way to fix this ‘just a blood pump’ in our bodies, regardless of whether it’s a biological or mechanical solution.

You’ve Got The Portable Radio, Now What About The Antenna?

July 28, 2024 by Jenny List 10 Comments

There’s an old saying in the amateur radio community that when it comes to antennas all you need is a piece of wet string. This may be a little fanciful, but it’s certainly true that an effective antenna can be made with surprisingly little in the way of conductor. It’s something [Evan Pratten VZ3ZZA] demonstrates amply with a description of the antenna he took camping in a Canadian provincial park.

Most of us would try some form of dipole on our adventures, but the antenna he’s using caught our eye as it’s described as an end-fed half-wave, but it has both a half-wave and quarter-wave element. Made from speaker cable or in this case thin mains cable for lamps, it’s obviously far from a perfect match and requires an ATU, but it generates an impressive array of FT4 contacts on a pretty meagre power level. We particularly like his in-plain-sight test run in the parking lot of a supermarket.

We frequently talk about the diversity of pursuits in amateur radio aside from that of the chequebook ham, and this project shows one of those. The world of QRP, operating at extreme low power, is not expensive to enter and can be extremely rewarding.

Hackaday Links: July 28, 2024

July 28, 2024 by Dan Maloney 14 Comments

What is this dystopia coming to when one of the world’s largest tech companies can’t find a way to sufficiently monetize a nearly endless stream of personal data coming from its army of high-tech privacy-invading robots? To the surprise of almost nobody, Amazon is rolling out a paid tier to their Alexa service in an attempt to backfill the $25 billion hole the smart devices helped dig over the last few years. The business model was supposed to be simple: insinuate an always-on listening device into customers’ lives to make it as easy as possible for them to instantly gratify their need for the widgets and whatsits that Amazon is uniquely poised to deliver, collecting as much metadata along the way as possible; multiple revenue streams — what could go wrong? Apparently a lot, because the only thing people didn’t do with Alexa was order stuff. Now Amazon is reportedly seeking an additional $10 a month for the improved AI version of Alexa, which will be on top of the ever-expanding Amazon Prime membership fee, currently at an eye-watering $139 per year. Whether customers bite or not remains to be seen, but we think there might be a glut of Echo devices on the second-hand market in the near future. We hate to say we told you so, but — ah, who are we kidding? We love to say we told you so.

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