A Spectrum Analyzer for $100!
How would you like a spectrum analyzer you can carry in your shirt pocket that costs only $99? A notebook or other Windows, Linux or Mac OS X based computer is required to communicate and power the device.
The Wi-Spy, offered by MetaGeek LLC
covers the 2.400 GHz to 2.483 GHz band, currently used by 802.11b/g/n Wi-Fi systems, microwave ovens, cordless phones, Zigbee systems and Bluetooth devices. The spectrum display should be useful when tracking down interference to wireless systems in this range.
of the Wi-Spy on TomsNetworking.com has full specifications and pictures of the inside of the device. The receive sensitivity of the device is -90 dBm.
It is not apparent in the photos that there is a place to connect an external antenna to the device. This doesn't necessarily prevent use of a high gain antenna. Large, inexpensive wok strainers (or even shallow woks themselves!) can be used as reflectors with the miniature USB thumb-drive size analyzer at the feed point. A USB extension cable will provide a connection to the computer.
I haven't had a chance to test the device. If any readers purchase it, I'd be interested in their comments. It would also be interesting to see if someone finds a way to reprogram the device to work over a wider frequency range.