The AR7000 combines an internal and remote receiver, offering superior path diversity.  The radio system simultaneously transmits on two frequencies, creating dual RF paths.  This dual path redundancy, plus the fact each of the two receivers is located in a slightly different location, exposes each to a different RF environment and creates a bulletproof RF link in all conditions. The AR7000 is now Flight Log compatible (SPM9540 sold separately).

Spektrum Flight Log 

Key Features 
Real-time voltage digital display 
Records individual antenna fades 
Records frame losses 
Records failsafes (holds) 
Overview 
Spektrums optional Flight Log is a unique tool that allows you to view the performance of your radio system like never before. With the revolutionary Flight Log, you can now quickly and easily view the real-time voltage supplied to your receiver, how many fades each internal receiver and remote receiver gets each flight, and if the system received any frame losses or failsafes (holds). 

The Flight Log is an optional component that was originally designed for testing, but now it is offered as a handy device that gives you a clear digital readout of your radio performance. The Flight Log is not required, but for complex aircraft, it provides an intuitive analysis of the overall performance of the radio installation. Some of todays models can be very demanding. The Flight Log ensures confidence that your system is working properly and you have optimized the radio installation. 

The Flight Log provides the following information: 

System voltage - receiver pack voltage 

Antenna fades represent the loss of a bit of information on that specific antenna. Typically its normal to have as many as 50 100 antenna fades on any one of the antennas during a flight. If any single antenna experiences over 500 fades in a single flight, the antenna should be repositioned in the aircraft to optimize the RF link. 

Frame Loss represents simultaneous antenna fades on all attached receivers. If the RF link is performing optimally, frame losses per flight should be less than 20. 

Hold a hold occurs when 45 contiguous (one right after the other) frame losses occur. This takes about one second. If a hold occurs during flight, it�s important to re-evaluate the system, moving the antennas to different locations and/or checking to be sure the transmitter and receivers are working correctly.