A $40 software-defined radio [Resources_Hands On]

The last time I ventured into the waters of software-defined radio (SDR) was seven years ago, when I reviewed Matt Ettus's Universal Software Radio Peripheral. While it's an excellent product, the basic motherboard at the time cost US $550; daughterboards for different frequency ranges cost $75 to $275 [see "Hardware for Your Software Radio," IEEE Spectrum, October 2006]. And I spent more than a few frustrating hours compiling the needed software on my MacBook Pro. This time I was able to get my feet wet for about $40–and the software took about 2 minutes to download, install, and run.