Hacking an Escape From East Germany

Some hacks are just for fun. Some make your job or your life easier. Once in a great while, a hack will save your family from an oppressive government. This is the kind of hack that [Günter] pulled off when he and [Peter] built a homemade hot air balloon to escape East Germany and the oppression of the Stasi in 1979.

Like many East Germans who weren’t in line with the Party, [Günter] found life unsatisfactory on his side of the Berlin Wall. Travel, job options, and freedom of expression were all severely limited. Aside from joining the Communist Party, the only option seemed to be escape to West Germany.

[Günter] and his wife [Petra] were inspired when [Petra]‘s sister, who had escaped in 1958, came to visit. She brought with her a newspaper that covered the International Balloon Fiesta in Albuquerque, New Mexico. [Günter] and [Peter], whom he worked with, decided that they would conspire to build a hot air balloon capable of transporting them, their wives, and their four children across the border.

Theirs is an incredible story fraught with adversity. They ended up constructing three different balloons, all the while traveling further and further from home to avoid suspicion when buying large quantities of fabric. They had a lot of trouble finding the right propulsion method and ended up using pure oxygen. During the narrow window they had before [Günter] was due to report for military duty, the weather was unfavorable except for a short period after a front had passed through. They had no time for testing and just went for it.

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Decoding News Helicopter Signals on YouTube

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A serendipitous YouTube video recommendation led [Oona] to a raw copy of a news helicopter car chase video. While watching the video she noticed an odd sound playing from her left speaker. That was all it took to put [Oona] on the hunt. Decoding mystery signals is a bit of an obsession for her. We last saw [Oona] decoding radio signals for bus stop displays. She isolated the left audio channel and sent it through baudline software, which helped her determine it was a binary frequency shift keyed (BFSK) signal. A bit more work with SoX, and she had a 1200 baud bit stream.

Opening up the decoded file in a hex editor revealed the data. Packets were 47 bytes each. Most of the data packets was static. However, thee groups of bytes continuously changed. [Oona] decoded these numbers as latitude and longitude, and plotted the resulting data on Google Earth. Plotting her data against the position of the car in the video revealed a match. [Oona] had a complete track of the news helicopter as it followed the car. The telemetry data is in 7-bit Bell 202 ASCII, and is most likely part of an Interruptible Foldback (IFB) system used by the helicopter news crew and the studio producers. Click past the break for the YouTube video that started this all.

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Iowa Forensics Opts for a CSI Style Hack to Save their Budget

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There’s a very effective way of lifting dusty fingerprints from the field, or in a lab. It’s called an Electrostatic Dust Print Lifter — but as you can imagine, it is rather expensive from a forensic supply store. [Bradley VanZee] — from the Iowa Division for International Association for Identification — realized how simple a tool it was, and made his own for just over $50.

But first, how does it work? Electrostatic print lifting is a non-destructive process where you develop an electrostatic field on a sheet of “lifting film” which attracts the dust particles to stick to the film. It’s capable of recovering impressions from both porous and non-porous surfaces — even ones not visible to the naked eye.

Commercial versions of the tool cost upwards of $600-$800 + lift film. The first hack they realized is that instead of using proprietary lift film, it is just as effective to use car window tint instead! The second hack is even more clever — using a 80,000V tazor, some electrical leads, and some tinfoil you can create your own version of the tool. The aluminum foil acts as a ground, and the object you are inspecting is sandwiched between it and the lifting film. Holding the tazor with one electrode to the foil, you can trace the film using the other electrode at a distance, which induces an electrostatic charge in the film, attracting and capturing the dusty fingerprints. Allow the static to discharge, and store the film in a safe place to be digitized later!

Now obviously this is only really effective for flat objects, but it’s still a brilliant hack — especially to save your budget!

[Thanks John!]

Heatsink Tester Shows Thermal Resistance Isn’t Futile

[Bogdan] knows that it’s hard to model the cooling needs of any given project. It’s important to know how much heat a system can dissipate given the housing material, airflow opportunity, and the proximity of neighboring components. Inspired by an aluminium-walled enclosure that allows for mounted transistors, he devised and built a heatsink tester.

He’s using an ATXMEGA32A4U, a temperature sensor, and a IRF540 MOSFET. A specific power is dissipated across the transistor, and the temperature sensor measures the heatsink as close as possible to the transistor. Through the serial connection, he gets back the supply voltage, current, calculated power, DAC set, temperature, and calculated thermal resistance in the terminal.

[Bogdan]‘s tester assumes that it is reading the ambient temperature, so the circuit needs to warm up first. He found that an hour is generally long enough to reach this point. He also found that the system exhibits high thermal inertia, so it regulates the DAC output based on the dissipated power.

Tesla Coil Auto-Winder

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Tesla coils are awesome. But if you’ve ever built one, you know how tedious winding the secondary coil is. So [Krux] decided to build a machine to do it for him.

He’s currently working on his first Tesla coil — code-named Project Icarus — he doesn’t have all the logistics ironed out quite yet, but he’s been slowly collecting the components. What he does know is that he wants to use a 4.5″ secondary coil, using 22AWG magnet wire, meaning that’s a lot of turns! Since he’s also a member of a local hackerspace, he decided to make it a modular machine that can wind different sized coils for different sized projects.

Essentially, he’s built his own CNC lathe to accomplish this, well, missing one axis. There’s the main rotary axis, and a wire-guide that moves along it ensuring the coils are wrapped tightly without gaps. It’s an impressive build and you can tell he’s put a lot of thought into the design – He’s even got a semi-flexible 3D printed motor coupler on the wire-guide axis, to help mitigate quick acceleration! The main rotary axis is also driven by a 3D printed herringbone style gear — similar to the style used on Printrbot extruders. The rest of the build is made of plywood and pegboard — allowing for even larger coils to be wound by shuffling around the components. He’s even got a full featured command console with manual/automatic controls and an LCD giving feedback on the coil being wound!

Stick around after the break to see [Krux] explain the fascinating build, and to see a fun time-lapse of an 814-turn Tesla coil winding!

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12V Ammo Power Box Keeps it Retro

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[Brandon Fiquett] does a lot of amateur radio communications and needed a rugged portable power supply that he could take with him on the road. He decided to make a 12V power supply out of an antique ammo can he found at an army surplus store.

The .50 cal ammo box wasn’t in the greatest condition when he picked it up, so he completely sanded it, re-painted it, and lubricated the rubber seal. Inside, he loaded it with four 7.1Ah sealed lead acid batteries, complete with 12V cigarette fused sockets, banana plug jacks, a 5V USB charger and an integrated 12V lead-acid battery charger. The lid also features an LED strip light, and everything is laid out very nicely inside of the box. It looks great, but [Brandon] has a long list of improvements to add, including a solar charge controller, volt and amp meters, and an LED power switch.

Ammo cans make solid project boxes. We’ve seen countless ammo can speaker setups, and even a more intricate ammo can PSU – though we prefer [Brandon's] method since all the connections are under the lid, keeping it completely weather proof.

Bringing WiFi into a Mobile Hackerspace

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[Philipp Protschka] has a pretty awesome mobile hackerspace (MHS) trailer. The only problem? How do you get WiFi when you’re inside what is basically a Faraday’s cage?

He didn’t think he’d have a problem, since he has a fairly powerful router (Netgear R7000 Nighthawk), not more than 20m from the trailer. But as soon as he shuts the door, he loses all connectivity — he can’t even see his SSID. Leaving the door open a crack results in a signal with a speed of about 54Mbits — not bad, but when it’s cold outside this really isn’t an option.

The solution? Install a WiFi repeater with an external antenna. He’s using a TP link station with two antennas — he’s removed one and hooked it up to a rugged outdoor antenna that gives the MHS a bit of an FBI van look — awesome. With the repeater in place he’s suddenly got access to over 24 SSID’s in the neighborhood from inside! It’ll also be extra handy when travelling because with the extra range it means he’ll be able to hook into local WiFi networks with ease.

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