CPU As A Heat Sink

May 1, 2010 by Mike Szczys 51 Comments

We’ve noticed that wireless routers pump out a bunch of heat. [Jernej Kranjec] wanted to make sure that he didn’t fry it once he started adding more load to his router using OpenWRT. What he came up with is the idea of using an old CPU as a passive heat sink. He applied a bit of thermal paste to the center and some super glue to the corners. You can see the finished product is an old AMD chip adhered “dead bug” style to the stock processor. We’d bet it’s not very efficient compared to an aluminum or copper heat sink, but it normally would have no help in shedding those extra degrees.

Chumby One Becomes A 3g Router

April 29, 2010 by Caleb Kraft 19 Comments

[bunnie] has taken a few moments to show us how to turn our Chumby One into a 3g router. As it turns out, there is an easter egg that allows it to communicate with certain models of 3g dongles. There’s no GUI for this trick, so you’ll be doing most of your configuration via SSH. That shouldn’t be a problem for this crowd though. The Chumby One just got a lot more appealing.

RF Transmission In The 9 KHz Band

April 25, 2010 by Mike Szczys 31 Comments

[W1VLF] is on a quest to communicate over long distances with a 9 kilohertz transmitter. He built this giant coil with that in mind. A round concrete form was used as a base and wound with magnet wire by hand. We’d recommend building an automated winding device, but this method seems to have worked. Operating at 50 Watts on the air-core coil at 8.97 KHz he was able to pick up the signal at a distance of 5 kilometers. It’s not breaking any overall distance or portability records, but on a project like this the quest is where the fun is at.

[Thanks Drone]

WiFi And Bluetooth Sniffing Rifle

April 23, 2010 by Mike Szczys 52 Comments

[.ronin] built an all-in-one WiFi and Bluetooth sniffer. He used a Nerf rifle as a base and added two Pringles cantennas, a tablet PC, and other various bits to tie it all together. Now he wanders the streets, explaining the device to bewildered passersby. After showing the device at CarolinaCon 2010 (here’s a PDF of his presentation) he stopped by the mall nibbled about 250 Bluetooth devices using SpoofTooph. The software is running on a Fujitsu u810 tablet and he’s making good use of Backtrack 4 during his wireless adventures.

Infrared Transmission Decoding

April 21, 2010 by Mike Szczys 12 Comments

Alright class, quiet down and open your books to the chapter on Manchester Encoding. [Brian J Hoskins] did just that when building this RC5 decoder. This protocol is commonly used in television remote controls. You use them on a daily basis, don’t you think it’s time you understood what’s going on? Check out his writeup and learn the dark art of invisible light communication. Or just skip the learning and follow our how-to.

[Thanks Tim]

All About VLF Radio

April 14, 2010 by Mike Szczys 20 Comments

If you’re interested in learning about Very Low Frequency communications take a look at what Larry has to offer on his site. He’s put together a guide to VLF receivers that is short enough to read and clear enough to understand with rudimentary knowledge of circuits. He builds a simple receiver as a working example and a high-powered transmitter that can put out over 2600 watts. Let’s face it, radio operators were the original electronic hackers. Get back to our roots and learn the ways of the transistor.

[Thanks Buddy]

Building A Window Mounted Antenna For Your Car

April 12, 2010 by Mike Szczys 16 Comments

If you’re into ham radio and want it when you’re on the go give this antenna mount a try. [Cirictech] started with a design from the November 2009 issue of QST and added his own fabrication touches. Everything except the antenna itself is available from the hardware store for just a few bucks, and you should be able to complete this project in a flash. This makes us wonder what the antenna for the 47 GHz band radio setup would look like.