Hi ringolong is right range check, if its a futaba or spektrum the range is normal 1km , these transmitter have a program call range check what it does is cuts out put to 1/2 then you walk 90 paces from the quad and then arm it , if it does your good for full range , for other quads do what Ringolong said remove props get a friend to walk across the park till they are long away then try and arm it if it wont get them to slowly walk back till you can arm this is then the max range , its important if you dont have return home , or flying FPV as the FPV signal may not drop till after the quad is out of range of its transmitter