If you haven't read this thread:
http://www.ausrocketry.com/forum/viewtopic.php?f=32&t=1590
Then you really need to before you continue.
Assuming you won't read it, here's a summary:
This little board installs into a UHF CB or FRS (or any other type of) radio and takes the data from a GPS, encodes it into beeps and squeaks, and transmits it.
Big deal? Well yes. Using UHF CB or FRS (both in the 400MHz range) you get double the range for the same power as a 900MHz system. The data is transmitted as an
APRS packet, so there's lots of free software to look at the data.
You'll need to be handy with a soldering iron to install this in your radio, but it's not that hard.
Again, read the thread and get in touch if you have any questions.
PK