I have the Spektrum DX7s with the AR8000 reciever and i am flying a 3DR APM 2.6 that has ArduCopter V3.1 installed. When i do a radio calibration the lower limit for channel 3 when i have the radio turned on is 1134. When i turn the radio off it drops to 1127. So what i would like to do is to set my FS_THR_VALUE to 1130 so that my copter will fly home if my radio dies. But when i set this value i get a never ending PreArm: Check FS_THR_VALUE error and my copter will never arm. In doing a little digging around (and looking at the source code) it appears that the upper range for this value is set to 1100.So of course my question is: what can i do about this? How can i get my copter to fly home if my transmitter dies?