Dodgy Hotel, Beer and A WWII Era Tube Receiver

bc-22e ww2 reciever operating in a hotel

In the luxurious accommodations provided by Motel 8 and armed only with a few tools and a six pack – a pair of amateur radio enthusiasts attempted the repair of an old WWII era BC-224E receiver. They picked up the boat anchor antique receiver, which was in unknown condition, from a flea market while in town for the Dayton Hamvention, brought it back to their hotel and got to work.

The BC-224E came in two parts – the receiver and the power supply. The speaker for the system, which is actually located in the power supply, is driven by a large inductor.  Apparently when the receiver was constructed, the permanent magnets of the day were not powerful enough to drive a speaker.

Fortunately, the receiver also came with some schematics, allowing [Gregory] and his fellow radio enthusiast to reverse engineer the power supply. After a few tweaks and cap swaps, they crossed their fingers and plugged it in. Stay tuned to see what happened next.

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Discovering a Wifi Enabled 10MHz Oscilloscope

 

As most of our readers know, [Mike] was visiting Bay Area Maker Faire  last weekend with a big Jolly Wrencher on his back. During his tour he encountered the neat oscilloscope shown in the video above, made by the Belgian company Velleman. Even though it only has a 10MS/s sampling rate and a 10MHz bandwidth, our guess is that it may still be useful for some hobbyists out there as it can communicate with any PC/smartphone/tablet using its Wifi interface.

Inside the black box is a 3.7V 1800mAh Li-ion battery with a USB port to recharge it or update the oscilloscope’s firmware. As seen in the video, the tablet’s touchscreens may enable more natural interaction with the user interface. The protocol used to export the acquired samples is open, which may allow users to create their own analysis program. The oscilloscope uses an 8 bit analog to digital converter and a 4K samples buffer.

Electromagnetic Boots For All Your Upside Down Needs!

magnet boots

X-Men: Days of Future Past is making its way to theaters around the world, and [Mr. Furze] has released his second X-Men related hack — Magneto Boots.

In case you missed it, [Colin Furze] has made three projects to celebrate geekdom and a mastery of fabrication for all the comic book fans out there. He started with the fully functional pneumatic Wolverine Claws, and now he’s tackling Magneto’s powers. The third project isn’t out quite yet, but we can’t wait to see the final installment!

Now the problem with Magneto is his powers are a wee bit too… magical? Without special effects, you can’t really replicate his mutant abilities (please prove us wrong if you can!), so [Colin] decided to do the next best thing. Magnetize himself — well, his shoes.

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Repairing a Nikon D3

headless

There are few products out there as electronically and mechanically complex as a modern DSLR. Between the sensor, shutter, various LCD screens, and Flexible Printed Circuit boards (FPC) running everywhere, it’s enough to make even the most organized DIY repair person quake in fear. [TiN] over at the EEVblog forums wasn’t scared off though, as he bought a broken Nikon D3 on eBay in hopes of repairing it.

The D3 was Nikon’s top of the line professional camera in 2008. With a 12 Megapixel Full frame sensor and a host of other features, used models still command a good portion of the original $5000 USD price. [TiN's] camera was described as having been dropped, and was dead on arrival, exactly as it had been described on eBay. The battery door was destroyed, so [TiN] connected an external supply. The camera was still dead, so it was time to dig in. Thanks to the internet, [TiN] was able to find a service manual for the camera. He decided to check the power supply board next. A TO225 package transistor with an obvious hole blown in the front was a good starting point.

[TiN] replaced the transistor and the camera sprang to life. The main LCD showed the live sensor view, and it would take pictures. All was not perfect though, as the two auxiliary LCDs were still dead, and the D3′s mirror would get stuck every other shot, leading to an error display.

Click past the break for the rest of [TiN's] story.

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[Ben Krasnow] and His 8 kJ Ruby Laser

 

We were again pleased to find another person who attended Maker Faire just to show off the awesome and not to hawk some goods. In our mind [Ben Krasnow] represents the highest echelon of hardware hacking (apparently Google[x] agrees because they just snatched him up) . But [Ben] always makes a point to explain how he does what he does so that others may learn and someday achieve a similar type of greatness. This time around it’s a functional ruby laser which is backed by a capacitor bank that stores a whopping 8 kilojoules of energy. This is what allows the laser to cut through steel plate. He sure has come a long way since he first showed off the project in January.

Unfortunately we didn’t get to [Ben's] booth until late on Sunday. His previous demonstrations burned through some seals and left him with a non-functional laser. But he’s a trustworthy guy so we believe him and look forward to him posting a video about the laser and hopefully about the failure. He also mentions that he may make an attempt at lunar laser ranging with this device; bouncing the laser off of reflectors on the moon and measuring the delay. This can then be used to calculate the distance to the moon.

By the way, it was super difficult not to crack a joke when he says the words “Ruby Rod“.

Homemade Liquid Nitrogen

n

As far as DIY cryogenics are concerned, dry ice is easy mode. You can get frozen carbon dioxide at WalMart, or from a nozzle that screws onto a CO2 tank. It’s all very ordinary, and not really special at all. Want to know what’s cool? Making liquid nitrogen at home.

[imsmooth] is getting his nitrogen from a standard tank, sending the gas through a CO2 and H2O scrubber, compressing it, putting the compressed gas in an ice bath, and slowly diffusing the compressed, cooled gas into a vacuum reservoir. When the cold compressed gas is released into the reservoir, Boyle’s law happens and liquid nitrogen condenses in a flask.

As far as materials and equipment are concerned, [imsmooth] is using a PVC tower filled with zeolite to filter out the CO2 and H2O, a SCUBA compressor (no oil), and an almost absurd amount of stainless steel tubing for the precooler and regenerative cooling tower. Except for a few expensive valves, dewar, and the SCUBA compressor, it’s all stuff you could easily scrounge up from the usual home improvement stores.

[imsmooth] is producing about 350cc/hr of liquid nitrogen,  or more than enough for anyone who isn’t running an industrial process in their garage. Check out the video of the build below.

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The Pi CNC Controller

pi

Back in the olden days, the latest and greatest CNC machines had minicomputers bolted onto their frames, replete with paper tape readers and seven segment displays. For the home CNC machinist of today, these hulking electronic brains are replaced with something a little more modern – desktop computers with parallel ports. Having a box filled with computers and motor drivers is just too cool though, and this tiny Raspberry Pi CNC controller fits the bill quite nicely.

The controller uses a Raspberry Pi as the brains of the device, but there aren’t too many options out there for stepper motor control in Pi land. There are, however, dozens of CNC shields or the Arduino. The Pi AlaMode board is able to provide voltage level conversion between the CNC shield and the pi, and also has the nice bonus of a battery-backed real time clock.

With some proper connectors, lighted buttons, and a beautiful cable sleeving job, this Pi CNC controller would be well suited for any of the desktop CNC  or engraving builds we see from time to time.