Last week, I went over the basics of DIY robot bird-watching. In the video, I demonstrated the use of a Robot Bird Rescue Electronic Indicator Device (RBREID), a wireless receiver which can decode robot bird distress signals and estimate the bird's proximity. As you might imagine, the professional version of this tool is expensive and has scads of crazy features we don't need. So rather than blowing $15,000 on the real thing, we're going to build our own.
I know what you're thinking, and you're right: it's time to make a trip to your local Army or Navy surplus store. Don't worry though. If you know what to look for, you can get everything you need for under $50.
Here's what you need, and where you'll find it:
As you can see, most of the components can be harvested from the MS-R32 Mine Sweeper. Depended upon heavily during the first Gulf War, these analog explosive detection devices are just plain obsolete with the advent of digital signal processing (DSP). But that doesn't mean they don't work! You can pick one up cheap at any good surplus store.
The rest you can grab at any hobby shop. Expect to pay $5 - $10 for the radiologists dish, (sometimes called a ferrite loopstick antenna
). The radiologists dish is commonly used in conjunction with a directional antenna to compensate for ambient noise (this is similar to the concept of a twisted pair
). In this design, we use the radiophillic nature of the dish to point us in the direction of our feathered robot pal.
Once you have obtained the components, simply assemble them as shown in the video. The radiologists dish will be attached in series with the capacitance inductor coil and the MR712 chipset. While you can get away with using hot glue on this project, it's best if you have some proficiency with a soldering iron.
Labels: experiment, radio, robot birds