Hackaday Links: May 24, 2020

We’re saddened to learn of the passing of Gershon Kingsley in December 2019 at the age of 97. The composer and electronic music pioneer was not exactly a household name, but the things he did with the Moog synthesizer, especially the surprise hit “Pop Corn”, which he wrote in 1969, are sure to be familiar. The song has been covered dozens of times, in the process of which the spelling of the name changed to “Popcorn.” We’re most familiar with the 1972 cover by Hot Butter, an earworm from our youth that doesn’t hide the Moog as deeply in the backing instruments as Kingsley did in the original. Or, perhaps you prefer the cover done by a robotic glockenspiel, because robotic glockenspiel.

A few months back, we covered the audacious plan to recover the radio gear from the Titanic. At the time, the potential salvors, Atlanta-based RMS Titanic, Inc., were seeking permission to cut into the submerged remains of the Titanic‘s Marconi room to remove as much of the wireless gear as possible. A federal judge granted permission for the salvage operation last Friday, giving the company the green light to prepare an expedition for this summer. The US government, through the National Oceanic and Atmospheric Administration and the National Park Service, argued strenuously to leave the wreck be and treat it as a tomb for the 1,527 victims. For our part, we had a great discussion about the merits in the comments section of the previous article. Now that it’s a done deal, we’d love to hear what you have to say about this again.

Although life appears to be slowly returning to what passes for normal, that doesn’t mean you might not still have some cycles to spare, especially when the time spent can bolster your skillset. And so if you’re looking to adding FPGAs to your resume, check out this remote lab on FPGA vision systems offered by Bonn-Rhein-Sieg University. The setup allows you to watch lectures, download code examples, and build them on your local computer, and then upload the resulting binaries to real hardware running on the lab’s servers in Germany. It sounds like a great way to get access to FPGA hardware that you’d otherwise have a hard time laying hands on. Or, you know, you could have just come to the 2019 Hackaday Superconference.

Speaking of skill-builders, oscilloscope owners who want to sharpen their skills could do worse than to listen to the advice of a real scope jockey like Allen Wolke. He recently posted a helpful video listing the five most common reasons for your scope giving “wrong” voltage readings. Spoiler alert: the instrument is probably doing exactly what you told it to do. As a scope newbie, we found the insights very helpful, and we can imagine even seasoned users could make simple mistakes like using the wrong probe attenuation or forgetting that scope response isn’t flat across its bandwidth.

Safety tip for the gearheads among us: your jack stands might be unsafe to use. Harbor Freight, the stalwart purveyor of cheap tools, has issued a recall of two different models of its jack stands. It seems that the pawls can kick out under the right conditions, sending the supported load crashing to the ground. This qualifies as a Very Bad Day for anyone unlucky enough to be working underneath when it happens. Defective jack stands can be returned to Harbor Freight for store credit, so check your garage and be safe out there in the shop.

And finally, because everyone loves a good flame war, Ars Technica has come up with a pronunciation guide for common tech terms. We have to admit that most of these are not surprising; few among the technology literate would mispronounce “Linux” or “sudo”. We will admit to a non-fanboy level of ignorance on whether the “X” in “iOS X” was a Roman numeral or not, but learning that the “iOS” part is correctly pronounced as three syllables, not two was a bit shocking. It’s all an exercise in pedantry that reminds us of a mildly heated discussion we had around the secret Hackaday writers’ bunker and whether “a LED” or “an LED” is the correct style. If the Internet was made for anything, it was stuff like this.

Raising The Titanic’s Radio Room

For some reason, of all the ships that have sailed the oceans, it’s the unlucky ones that capture our imagination. Few ships have been as unlucky as the RMS Titanic, sinking as she did on the night of April 15, 1912 after raking across an iceberg on her maiden voyage, and no ship has grabbed as much popular attention as she has.

During her brief life, Titanic was not only the most elegant ship afloat but also the most technologically advanced. She boasted the latest in propulsion and navigation technology and an innovation that had only recently available: a Marconi wireless room, used both for ship-to-shore and ship-to-ship communications.

The radio room of the Titanic landed on the ocean floor with the bow section of the great vessel. The 2.5-mile slow-motion free fall destroyed the structure of the room, but the gear survived relatively intact. And now, more than a century later, there’s an effort afoot to salvage that gear, with an eye toward perhaps restoring it to working condition. It’s a controversial plan, of course, but it is technologically intriguing, and it’s worth taking a look at what’s down there and why we should even bother after all these years.

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The Comforting Blue Glow Of Old Time Radio

When you think of an old radio it’s possible you imagine a wooden-cased tube radio receiver as clustered around by a 1940s family anxious for news from the front, or maybe even a hefty 19-inch rack casing for a “boat anchor” ham radio transmitter. But neither of those are really old radios, for that we must go back another few decades to the first radios. Radio as demonstrated by Giulielmo Marconi didn’t use tubes and it certainly didn’t use transistors, instead it used an induction coil and a spark gap. It’s a subject examined in depth by [The Plasma Channel] and [Blueprint], as they come together to build and test a pair of spark gap transmitters.

This is a collaboration between two YouTube channels, so we’ve put videos from both below the break.They both build simple spark gap transmitters and explain the history behind them, as well as running some tests in RF-shielded locations. The transmitters are fairly crude affairs in that while they both use electronic drives for their induction coils they don’t have the resonant tank circuitry that a typical early-20th-century transmitter would have had to improve its efficiency.

They are at pains to remind the viewer that spark gap transmitters have been illegal for nearly a century due to their wideband interference so this is definitely one of those “Don’t do this at home” projects even if it hasn’t stopped others from trying. But it’s still a fascinating introduction to this forgotten technology, and both videos are definitely worth a watch.

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Origin Of Wireless Security: The Marconi Radio Hack Of 1903

The place is the historic lecture theater of the Royal Institution in London. The date is the 4th of June 1903, and the inventor, Guglielmo Marconi, is about to demonstrate his new wireless system, which he claims can securely send messages over a long distance, without interference by tuning the signal.

The inventor himself was over 300 miles away in Cornwall, preparing to send the messages to his colleague Professor Fleming in the theater. Towards the end of Professor Flemings lecture, the receiver sparks into life, and the morse code printer started printing out one word repeatedly: “Rats”. It then spelled out an insulting limerick: “There was a young man from Italy, who diddled the public quite prettily”. Marconi’s supposedly secure system had been hacked.

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History Of The Capacitor – The Modern Era

The pioneering years in the history of capacitors was a time when capacitors were used primarily for gaining an early understanding of electricity, predating the discovery even of the electron. It was also a time for doing parlor demonstrations, such as having a line of people holding hands and discharging a capacitor through them. The modern era of capacitors begins in the late 1800s with the dawning of the age of the practical application of electricity, requiring reliable capacitors with specific properties.

Leyden Jars

Marconi with transmitting apparatus
Marconi with transmitting apparatus, Published on LIFE [Public domain], via Wikimedia Commons
One such practical use was in Marconi’s wireless spark-gap transmitters starting just before 1900 and into the first and second decade. The transmitters built up a high voltage for discharging across a spark gap and so used porcelain capacitors to withstand that voltage. High frequency was also required. These were basically Leyden jars and to get the required capacitances took a lot of space.

Mica

In 1909, William Dubilier invented smaller mica capacitors which were then used on the receiving side for the resonant circuits in wireless hardware.

Early mica capacitors were basically layers of mica and copper foils clamped together as what were called “clamped mica capacitors”. These capacitors weren’t very reliable though. Being just mica sheets pressed against metal foils, there were air gaps between the mica and foils. Those gap allowed for oxidation and corrosion, and meant that the distance between plates was subject to change, altering the capacitance.

In the 1920s silver mica capacitors were developed, ones where the mica is coated on both sides with the metal, eliminating the air gaps. With a thin metal coating instead of thicker foils, the capacitors could also be made smaller. These were very reliable. Of course we didn’t stop there. The modern era of capacitors has been marked by one breakthrough after another for a fascinating story. Let’s take a look.

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J.C. Bose And The Invention Of Radio

The early days of electricity appear to have been a cutthroat time. While academics were busy uncovering the mysteries of electromagnetism, bands of entrepreneurs were waiting to pounce on the pure science and engineer solutions to problems that didn’t even exist yet, but could no doubt turn into profitable ventures. We’ve all heard of the epic battles between Edison and Tesla and Westinghouse, and even with the benefit of more than a century of hindsight it’s hard to tell who did what to whom. But another conflict was brewing at the turn of 19th century, this time between an Indian polymath and an Italian nobleman, and it would determine who got credit for laying the foundations for the key technology of the 20th century – radio.

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