Retrotechtacular: The Last Main Line

March 9, 2017 by Jenny List 14 Comments

If you were to nominate a technology from the 19th century that most defined it and which had the greatest effect in shaping it, you might well settle upon the railway. Over the century what had started as horse-drawn mining tramways evolved into a global network of high-speed transport that meant travel times to almost anywhere in the world on land shrank from months or weeks to days or hours.

For Brits, by the end of the century a comprehensive network connected almost all but the very smallest towns and villages. There had been many railway companies formed over the years to build railways of all sizes, but these had largely conglomerated into a series of competing companies with a regional focus. Each one had its own main line, all of which radiated out from London to the regions like the spokes of a wheel.

A Ruston steam navvy excavating near Wembley, London. S.W.A.Newton/Leicestershire County Council (Fair use)

By the 1890s there was only one large and ambitious railway company left that had not built a London main line. The Great Central Railway’s heartlands lay in the North Midlands and the North of England, yet had never extended southwards. In the 1890s they launched their ambitious scheme to build their London connection, an entirely new line from their existing Nottingham station to a new terminus at Marylebone, in London.

Since this was the last of the great British main lines, and built many decades after its rivals, it saw the benefit of the century’s technological advancement. Gone were the thousands of navvies (construction workers, from “Navigational”) digging and moving soil and rock by hand, and in their place the excavation was performed using the latest steam shovels. The latest standards were used in its design, too, with shallow curves and gradients, no level crossings, and a wider Continental loading gauge in anticipation of a future channel tunnel to France This was a high-speed railway built sixty years before modern high-speed trains, and nearly ninety years before the Channel Tunnel was opened.

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Das Fix

March 9, 2017 by Jenny List 35 Comments

There was a time when the desktop peripherals such as your keyboard and mouse were expensive items that you hung on to and cared for. But several decades of PC commoditization and ever-cheaper manufacturing have rendered each of them to an almost throwaway level, they are so cheap that when one breaks you can simply reach for another without thought.

This is not to say that there is no longer a space for a more costly specialist keyboard. You’ll find enthusiasts still clinging to their treasured vintage IBM Model Ms and Model Fs, or typing on a range of competing high end ‘boards. You might say that a cheap keyboard is pretty high quality these days, but for some people only the feel of a quality switch will do.

[Mac2612] was given a particularly nice example of this class of peripheral, a Das Keyboard 4C complete with trademark missing key decals. There was a snag though, it has suffered a spill at some time in its life, and would issue random keypresses which rendered it useless. His marathon investigation and repair of the fault makes for an interesting read, and gives us some insight into why these keyboards cost the extra money.

“To my dismay, I quickly realized that this was probably an unnecessary endeavor…”

At first it seemed as though corrosion on the board might be the issue, so he gave it a clean with IPA. All to no avail, and so began a succession of further dismantlings and cleanups which culminated in the desoldering of all the key switches. This lengthy task shows us in detail the construction of a high-end ‘board, but sadly it didn’t reveal the fault, and phantom keypresses kept appearing.

Following the board traces back to the microcontroller, he eventually found that moisture had corroded the end of a 10K surface mount resistor, leaving it with a resistance in the MOhms. Since it was a pulldown for one of the keyboard rows, he’d found the source of the problem. Having spent a long time fault-finding a board with an SMD part with a mechanical failure, we feel his pain.

Replacing the SMD parts and reassembly gave him a rather sweet keyboard, albeit for a lot of work.

This is the first Das Keyboard teardown we’ve brought you, but not the first keyboard hack. There are the people remanufacturing the Model F, for example, or the most minimalist keyboard possible.

[Thanks Graham Heath, via /r/MechanicalKeyboards]

Move Over Baofeng, Xiaomi Want To Steal Your Thunder

March 8, 2017 by Jenny List 56 Comments

To a radio amateur who received their licence decades ago there is a slightly surreal nature to today’s handheld radios. A handheld radio should cost a few hundred dollars, or such was the situation until the arrival of very cheap Chinese radios in the last few years.

The $20 Baofeng or similar dual-bander has become a staple of amateur radio. They’re so cheap, you just buy one because you can, you may rarely use it but for $20 it doesn’t matter. Most radio amateurs will have one lying around, and many newly licensed amateurs will make their first contacts on one. They’re not even the cheapest option either, if you don’t mind the absence of an LCD being limited to UHF only, then the going rate drops to about $10.

The Baofengs and their ilk are great radios for the price, but they’re not great radios. The transmitter side can radiate a few too many harmonics, and the receivers aren’t the narrowest bandwidth or the sharpest of hearing. Perhaps some competition in the market will cause an upping of the ante, and that looks to be coming from Xiaomi, the Chinese smartphone manufacturer. Their Mijia dual-band walkie-talkie product aims straight for the Baofeng’s jugular at only $35, and comes in a much sleeker and more contemporary package as you might expect from a company with a consumer mobile phone heritage. Many radio amateurs are not known for being dedicated followers of fashion, but for some operators the sleek casing of the Mijia will be a lot more convenient than the slightly more chunky Baofeng.

This class of radio offers more to the hardware hacker than just an off-the-shelf radio product, at only a few tens of dollars they become almost a throwaway development system for the radio hacker. We’ve seen interesting things done with the Baofengs, and we look forward to seeing inside the Xiaomi.

We brought you a look at the spurious emissions of this class of radio last year, and an interesting project with a Baofeng using GNU Radio in a slightly different sense to its usual SDR function.

[via Southgate ARC]

Do You Know Oleg Losev? An Engineer Tragically Ahead Of His Time

March 8, 2017 by Jenny List 73 Comments

It is so often the case with a particular technological advance, that it will be invented almost simultaneously by more than one engineer or scientist. People seem to like a convenient tale of a single inventor, so one such person is remembered while the work of all the others who trod the same path is more obscure. Sometimes the name we are familiar with simply managed to reach a patent office first, maybe they were the inventor whose side won their war, or even they could have been a better self-publicist.

When there are close competitors for the crown of inventor then you might just have heard of them, after all they will often feature in the story that grows up around the invention. But what about someone whose work happened decades before the unrelated engineer who replicated it and who the world knows as the inventor? They are simply forgotten, waiting in an archive for someone to perhaps discover them and set the record straight.

Oleg Losev (Public domain) — [Oleg Losev] (Public domain)

Meet [Oleg Losev]. He created the first practical light-emitting diodes and the first semiconductor amplifiers in 1920s Russia, and published his results. Yet the world has never heard of him and knows the work of unrelated American scientists in the period after the Second World War as the inventors of those technologies. His misfortune was to born in the wrong time and place, and to be the victim of some of the early twentieth century’s more turbulent history.

[Oleg Losev] was born in 1903, the son of a retired Russian Imperial Army officer. After the Russian Revolution he was denied the chance of a university education, so worked as a technician first at the Nizhny Novgorod Radio laboratory, and later at the Central Radio Laboratory in Leningrad. There despite his relatively lowly position he was able to pursue his research interest in semiconductors, and to make his discoveries.

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Hull Pixel Bot, A Mobile Pixel

March 6, 2017 by Jenny List 3 Comments

There are many designs for little two-wheeled robots available to download for constructors with an interest in simple robotics. You might even think there are so many that there could not possibly be room for another, but that has not deterred [Rob Miles]. He’s created HullPixelBot, a platform for a mobile pixel as well as for simple robotic experimentation.

So what makes HullPixelBot more than just Yet Another Arduino Powered Robot? For a start, it’s extremely well designed, and has a budget of less than £10 ($12.50). But the real reason to take notice lies in the comprehensive software, which packs in a language interpreter and MQTT endpoint for talking to an Azure IoT hub. This is much more than a simple Arduino bot on which you must craft your own sketches, instead, it is a platform for which the Arduino bot is merely the carrier.

The project has had quite a while to mature since its initial release, and now has the option of a single pixel or a ring of pixels. The eventual aim is to use swarms of networked HullPixelBots to create large autonomous moving pixel displays, containing more than a hundred individual pixels.

There is an early video of some PixelBots in action which we’ve placed below the break, but it serves more as eye candy than anything else. If you have a spare ten quid, download and print yourself a chassis, install Arduino and motors, and have a go yourself!

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From 1950s Multimeter To Internet Connected Clock

March 4, 2017 by Jenny List 6 Comments

We’ve seen many clocks here over the years. Some of them are conventional, some esoteric. So it’s not often that we see something novel in the world of timekeeping.

Strictly speaking, [Giulio Pons]’s clock project isn’t new at all. He’s taken a broken multimeter from the 1950s, and with the help of an Arduino Nano and an ESP8266 module, converted it into a clock that indicates the time on the multimeter’s moving-coil meter. He’s wired the multimeter’s front panel controls to the Arduino to operate the thing, and given it a speaker to play alarm sounds. A PIR motion detector activates the clock. In the hours of darkness, a photoresistor brings up a light. Time setting is automatic via the internet. [Giulio] previously experimented with an RTC module but found the network connection made changing time settings easier.

It’s by no means the perfect timepiece. For instance, [Giulio] found that driving the meter from a PWM pin gave different readings depending on the PSU load from other parts such as the light. But the clock does work, and has breathed new life into what might otherwise have remained a piece of junk.

Those of you with long memories might remember a similar project from a few years ago that used unmodified multimeters to display time as voltage. And of course, there are always frequency counter clocks.

Record Players Explained For The Streaming Generation

March 3, 2017 by Jenny List 68 Comments

How do you consume your music, these days? Aside from on the radio, that is. Do you play MP3 or other files on your phone and computer, or perhaps do you stream from an online service? If you’re really at the cutting edge though you’ll do none of those things, because you’ll be playing it on vinyl.

The legendary Technics SL1200 direct-drive turntable, as used by countless DJs. Dydric [CC BY-SA 2.5)], via Wikimedia Commons. — The legendary Technics SL1200 direct-drive turntable, as used by countless DJs. Photo by Dydric CC-BY-SA 2.5

A few years ago reporting on a resurgence of sales of vinyl records was something you would never have expected to see, but consumer tastes are unpredictable. Our red-trousered and extravagantly bearded hipster friends have rediscovered the glories of the format, and as a result it’s popping up everywhere. For those of us who are old enough to have genuinely been into the format before it was cool again, the sight of Sergeant Pepper and Led Zeppelin II on 12″ at outrageous prices on a stand at the local supermarket is a source of amusement. It’s good to see your first love back in vogue again, but is it really the £20($25) per album kind of good?

With the turntable having disappeared as an integral part of the typical hi-fi setup the new vinyl enthusiast is faced with a poor choice of equipment. Often the best available without spending serious money at an audiophile store is a USB device with the cheapest possible manufacture, from which the playback will be mediocre at best. We’ve lost the body of collective knowledge about what makes a good turntable to almost thirty years of CDs and MP3s, so perhaps it’s time for a quick primer.

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