Walkera Devo 7/RX701 Transmitter Range Test

Length of road is about 230 meters. Walked the length with a wifi scanner app, none found. Dropped the heli at one end, pointed a keychain cam at it, walked to the other with my phone camera pointed at the Devo7. When i got home, i played both videos simultaneously and by looking it up on google earth, i was able to work out the distances. Moving away from the heli, servos became erratic just before 80meters (2:02) On the way back to the heli, the TX started responding again at 140 meters (4:57)