We were looking for something to help secure the driveway and notify us when someone shows up even if we are out in the back corner of the property, I stumbled across the murs radio system from Dakota alert
These devices are battery powered and sense motion up to 80 ft away and then trigger a radio that broadcasts a message like “alert zone 1” and can transmit up to 6 miles away to a hand held unit depending on the terrain. Murs is a group of channels that the fcc has allowed people to use without a licence much like the CB radio band. Instead of buying the receiver to go with it I used a existing hand held scanner that I had.
The murs band uses these 5 freqs
If you are a ham radio guy you can program the murs freqs into your handheld
Here is some shots from the inside of the radio.
It appears that the motion sensor part just relays power out to the radio board so i’d assume you could use the radio board as a stand alone for many things, you could hook it to a dry contact for a door sensor, you could hook it to a float switch for monitoring water in a tank or a basement that floods, you could hook it to literally anything that you want to monitor. I haven’t played with it much yet but I could see the possibilities to be endless with some creativity. Thinking of adding a solar panel to mine first so I don’t have to change batteries every 6 months. I could see it being handy for a remote watering station and all sorts of security applications.