On Sun, Jul 20, 2008 at 4:22 PM, Wes Johnston, AI4PX <wes at ai4px.com> wrote: > Why not use those little 433mhz data transmitters? I hooked an early prototype SMT OpenTracker to one of these (audio model, not the typical data units). Frequency drifted a bit with temperature extremes, but it was standard APRS decoded with a 70cm rig. -Jason kg4wsv