I had similar range test concerns with my SD-10 purchased in May. Range testing was done in two places, at the field during a contest and in my small back yard. Both were close to other 2.4 ghz transmitters (radios, internet and telephone). Range for my RX500 and RX600 receivers was roughly 40 feet. The RX700 range tested at 65 feet. This is the distance when dropout (twitching of servo) was noted.

I sent my SD-10 and RX500 and RX600 to Airtronics service to be checked out. Airtronics reported that everything was fine with the radio and receivers. They checked internal connections for broken wires and checked the range and function. The technician I talked to said he would expect this type of performance range checking in a noisy area.

I neglected to say that my Futaba 9CAP with Futaba 2.4ghz module had full performance in low power mode well beyond this distance.

Nathan King, can you report back with your range test after repair.