Always wanted one of those wickedly-cool spectrum analysers to find the best channel for your wireless router, but don't have the readies to ever afford such a device? How's about a relatively simple home-made unit costing around £15?
In a project posted to his 2.4GHz radio website
, Jason Hecker shows how someone with moderate skill in holding a soldering iron by the cold end can turn $20 worth of parts into a fully-working 2.4GHz spectrum analyser.
The schematic is available here
, and the good news is that it's not particularly complicated. All you need is a wireless transceiver chip – Jason recommends the Cypress Semiconductor CYM6935
– a few resistors and diodes, a DB-25 connector and the ever-handy prototyping board.
The observant readers will have noticed from the parts list, this is a parallel-port unit: owners of PCs that have lost their legacy port will have the fun of getting a USB-to-Parallel adaptor working in order to use their creation. Once completed, however, the software Jason provides will give you a neat-o graphical display of noise levels on the full range of channels used by 802.11 wireless networks.
It's not a project for everyone, but I can certainly see the device coming in handy for doing site surveys before configuring a new wireless device or for discovering the cause of poor performance of an existing device. And for the investment, you can't really go wrong.
If you're handy with a soldering iron and are looking for something fun to do this weekend, give it a go and let us know how you get on over in the forums