"Ed_G" wrote in message
You might do a bit of research on the equipment that various animal
tracking organizations use. They tend to use the 215 - 218 MHz band for
tracking various animal species, and the equipment should suit your needs
also.

Thanks Ed. That's a good idea, and you're exactly right... what we're doing
looks just like what you'd see on a television nature show where someone had
a radio collar on a lion or something like that. We're applying the same
technology to Alzheimer's patients who are at risk of wandering.