Spy Tech: Unshredding Documents

June 12, 2023 by Al Williams 38 Comments

Bureaucracies generate paper, usually lots of paper. Anything you consider private — especially anything that could get you in trouble — should go in a “burn box” which is usually a locked trash can that is periodically emptied into an incinerator. However, what about a paper shredder? Who hasn’t seen a movie or TV show where the office furiously shreds papers as the FBI, SEC, or some other three-letter-agency is trying to crash the door down?

That might have been the scene in the late 1980s when Germany reunified. The East German Ministry of State Security — known as the Stasi — had records of unlawful activity and, probably, information about people of interest. The staff made a best effort to destroy these records, but they did not quite complete their task.

The collapsing East German government ordered documents destroyed, and many were pulped or burned. However, many of the documents were shredded by hand, stuffed into bags, and were awaiting final destruction. There were also some documents destroyed by the interim government in 1990. Today there are about 16,000 of these bags remaining, each with 2,500 to 3,000 pieces of pages in them.

Machine-shredded documents were too small to recover, but the hand-shredded documents should be possible to reconstruct. After all, they do it all the time in spy movies, right? With modern computers and vision systems, it should be a snap.

You’d think so, anyway.

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Own More Than One ‘Scope? You’ve Got Nothing On This Guy!

May 24, 2023 by Jenny List 18 Comments

We’re guessing that quite a few of our readers have a surprising amount of redundant test gear, and we ourselves have to admit that more than one instrument adorns our benches. But we are mere dilettantes, amateurs if you will, compared to [Volke Kloke]. He’s got 350 of them in his average American home, and we have to say, among them are some beauties.

The linked newspaper article is sometimes frustratingly light on the details, but fortunately he has a website all of his own where we can all get immersed in the details. Of particular interest is an instrument which doesn’t even have a CRT, the General Radio 338 string oscillograph used a mirror drum to catch a standing wave in a tungsten wire, but there are plenty more. Is your first ‘scope among them?

As we now live in the age of cheap digital ‘scopes, at any surplus sale you’ll see plenty of CRT-based instruments going for relative pennies. Of those, the more recent and high-end ones are still extremely useful instruments, and it’s not just misty-eyed reminiscing to say that they remain a worthy addition to any bench.

Want to know about early ‘scope tech? We’ve taken a look before.

Space Shuttle Atlantis connected to Russia's Mir Space Station as photographed by the Mir-19 crew on July 4, 1995. (Credit: NASA)

The Soviet Space Station Program: From Military Satellites To The ISS

May 15, 2023 by Maya Posch 7 Comments

When the Space Race kicked off in earnest in the 1950s, in some ways it was hard to pin down where sci-fi began and reality ended. As the first artificial satellites began zipping around the Earth, this was soon followed by manned spaceflight, first in low Earth orbit, then to the Moon with manned spaceflights to Mars and Venus already in the planning. The first space stations were being launched following or alongside Kubrick’s 2001: A Space Odyssey, and countless other books and movies during the 1960s and 1970s such as Moonraker which portrayed people living (and fighting) out in space.

Perhaps ironically, considering the portrayal of space stations in Western media, virtually all of the space stations launched during the 20th century were Soviet, leaving Skylab as the sole US space station to this day. The Soviet Union established a near-permanent presence of cosmonauts in Earth orbit since the 1970s as part of the Salyut program. These Salyut space stations also served as cover for the military Almaz space stations that were intended to be used for reconnaissance as well as weapon platforms.

Although the US unquestionably won out on racing the USSR to the Moon, the latter nation’s achievements granted us invaluable knowledge on how to make space stations work, which benefits us all to this very day.

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Retro Gadgets: I Swear Officer, I Was Listening To 45

May 9, 2023 by Al Williams 15 Comments

Audio in cars has a long history. Car radios in the 1920s were bulky and expensive. In the 1930s, there was the Motorola radio. They were still expensive — a $540 car with a $130 radio — but much more compact and usable. There were also 8-tracks, cassettes, CDs, and lately digital audio on storage media or streamed over the phone network. There were also record players. For a brief period between 1955 and 1961, you could get a car with a record player. As you might expect, though, they weren’t just any record players. After all, the first thing to break on a car from that era was the mechanical clock. Record players would need to be rugged to work and continue to work in a moving vehicle. As you might also expect, it didn’t work out very well.

It all started with Peter Goldmark, the head of CBS Laboratories. He knew a lot about record players and had been behind the LP — microgroove records that played for 22 minutes on a side at 33.3 RPM instead of 5 minutes on a side at 78 RPM. He knew that a car record player needed to be smaller and shock-resistant. Of course, in those days, it would have tubes, but that could hardly be helped.

The problem turned into one of size. A standard 10- or 12-inch disk is too big to easily fit in the car. A 45 RPM record would be more manageable, but who wants to change the record every three or four minutes while driving?

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A History Of NASA Supercomputers, Among Others

May 5, 2023 by Dave Rowntree 8 Comments

The History Guy on YouTube has posted an interesting video on the history of the supercomputer, with a specific focus on their use by NASA for the implementation of computational fluid dynamics (CFD) models of aeronautical assemblies.

The aero designers of the day were quickly finding out the limitations of the wind tunnel testing approach, especially for so-called transonic flow conditions. This occurs when an object moving through a fluid (like air can be modeled) produces regions of supersonic flow mixed in with subsonic flow and makes for additional drag scenarios. This severely impacts aircraft performance. Not accounting for these effects is not an option, hence the great industry interest in CFD modeling. But the equations for which (usually based around the Navier-Stokes system) are non-linear, and extremely computationally intensive.

Obviously, a certain Mr. Cray is a prominent player in this story, who, as the story goes, exhausted the financial tolerance of his employer, CDC, and subsequently formed Cray Research Inc, and the rest is (an interesting) history. Many Cray machines were instrumental in the development of the space program, and now adorn computing museums the world over. You simply haven’t lived until you’ve sipped your weak lemon drink whilst sitting on the ‘bench’ around an early Cray machine.

You see, supercomputers are a different beast from those machines mere mortals have access to, or at least the earlier ones were. The focus is on pure performance, ideally for floating-point computation, with cost far less of a concern, than getting to the next computational milestone. The Cray-1 for example, is a 64-bit machine capable of 80 MIPS scalar performance (whilst eating over 100 kW of juice), and some very limited parallel processing ability.

While this was immensely faster than anything else available at the time, the modern approach to supercomputing is less about fancy processor design and more about the massive use of parallelism of existing chips with lots of local fast storage mixed in. Every hacker out there should experience these old machines if they can, because the tricks they used and the lengths the designers went to get squeeze out every ounce of processing grunt, can be a real eye-opener.

Want to see what happens when you really push out the boat and use the whole wafer for parallel computation? Checkout the Cerberus. If your needs are somewhat less, but dabbling in parallel computing gets you all pumped, you could build a small array out of Pine64s. Finally, the story wouldn’t be complete without talking about the life and sad early demise of Seymour Cray.
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Add A Little Quindar To Your Comms For That Apollo-Era Sound

April 30, 2023 by Dan Maloney 9 Comments

If there’s one thing that ties together all the media coming out of the Apollo era, it’s probably the iconic Quindar tones. These quarter-second beeps served as control tones for the globe-spanning communications network needed to talk to the Apollo astronauts, and any attempt to recreate the Apollo-era sound would be glaringly wrong without them. And that’s why [CuriousMarc] whipped up this Quindar tone system.

The video below starts with a detailed treatment of what Quindar tones are and why they were used, a topic we’ve covered ourselves in the past. To recap, Quindar tones are a form of in-band signaling, with a 2,525-Hz pure sine wave intro tone that signaled the transmitters connected to Mission Control in Houston over leased telephone lines to key up. The 2,475-Hz outro tone turned off the transmitters and connected the line to the receivers.

To recreate the sound quality of the original circuitry, and to keep in the retro vibe, [Marc]’s Quindar homage avoided digital circuitry as much as possible, opting instead to generate the two tones with an XR-2206 function generator chip. The chip can rapidly switch back and forth between two frequencies, making it perfect for FSK applications or, in this case, reproducing the two slightly different tones. [Marc] added a dual mono-stable multi-vibrator to pulse the tone, giving the 250-ms pulse, and an audio gate, which uses a MOSFET to switch the tone into an audio stream. All this got soldered up to a piece of perf board and stuffed in the base of a cheap intercom microphone, which while not period accurate still has a cool retro look — and now, a retro sound, too.

Hats off to [CuriousMarc] and his merry band for probing the mysteries of Apollo-era comms and keeping the accomplishments of all those engineers alive. The methods they used are still relevant after all these years, and there seems to be no end to what we can learn from them.

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Rising To The Occasion: A Brief History Of Crewed High Altitude Balloons

April 28, 2023 by Al Williams 11 Comments

Piccard inspects an instrument on his balloon (Image: Bundesarchiv, Bild 102-10382 / CC-BY-SA 3.0)

We think of human flight as a relatively modern affair, with a few claims to the first airplane all around the turn of the last century. But people flew much earlier than that by using hot air balloons as well as gas-filled ones. While the Montgolfier brothers get most of the credit for hot air ballooning in 1783, there are some reports that a Brazilian priest may have lifted himself with a balloon as early as 1709.

Regardless, we’ve had balloons a good century earlier than winged flight, if not longer. While the device is deceptively simple, it is possible to get a balloon to very high altitudes without a lot of specialized technology. Airplanes at high altitudes need a way to get enough oxygen to fuel their engines, or they have to rely on rockets. Either way, there are plenty of design and operational challenges.

Balloons, of course, can simply rise to the occasion. Auguste Piccard and an assistant took a gas-filled balloon to 15,781 meters in 1931. Their gondola was pressurized, and they were the first humans to see the curvature of the Earth and the dark sky above. That record wouldn’t stand for long, though.

CCCP-1

The Soviet Union was keenly interested in Piccard’s flight, and the Soviet Air Force set about to build a research vessel, CCCP-1 (in English, USSR-1), that flew in 1933. The envelope was a large amount of thin fabric impregnated with latex and filled with hydrogen. The air-tight gondola presented several challenges in design. Most of the science experiments were outside, of course, and in 1933, you didn’t have an Arduino and RC servos to control things.

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