I just purchased a receiver and two radio collars from Communications Specialists for cats. I have had some cats disappearing lately and am exploring the concept of tracking them to keep tabs. I had looked at the regular wildlife trackers but they are definitely much more expensive. The receiver with built in antenna costs 250$ and the collars are 49$ each. Uses CR 2032 batteries and those are sold for like 6 bucks a dozen. So far so good, I can keep track of the cats easily. Works well, the collars transmit pulses one second apart, and the batteries are claimed to last a month. The receiver is channelised, as are the collars, but the range of the receiver is stated as 218.25-223.29Mhz. The collars are Part 15 devices. The receiver is apparently working with a BFO, besides channel selection, there is a "tuning" control that adjusts the beep tone over a certain range. Has selectable attenuation and volume, and a meter. Runs on a 9 volt battery. Alum. case. Has a two element fold up antenna that is maybe moxon configured? element ends are bent towards each other. Has a pistol grip and with the ant. folded, fits in a pouch that goes on a belt. BNC connector would allow antenna options too. Well check out the device on the CSI website. This is the PR-100 receiver, and they make collars for cats, dogs, and a hanging loop type that you can attach to children or senile old hams. Fun but a useful device for me. That is why I bought it and am happy so far with the functioning.
www.thecatlocator.com