I've got a friend who lives on a farm and is wanting me to make 3 wireless relay switches that can work up to 500 meters. Can anyone tell me how to go about it so that their frequencies don't get muddled up? I also need them able to change around the transmitter they receive from (or vice-vesa).
Also, can someone please tell me what is legal and what isn't with wireless devices?
Australia and NZ are fairly free (have more licence free freq's then the rest of us around the globe)... but local shops are sure to know what is "locally licence free"