RE: Spektrum/JR CF receivers?
With DSMX, fades are no longer valid indicators of good or bad receiver placement. This is due to the addition of frequency hopping to the DSM architecture. If you have moved from DSM and are seeing higher frame losses using the same receiver placement, you could benefit using a carbon "satellite" or two to place the antennas further from carbon or metal components.
I did this with a Powerbox Royal Spektrum setup in my flite metaled BVM F-100. Although it is a DSM system I saw very high fade numbers and higher than normal frame losses. Replacing two of the original receivers with the carbon receivers and placing the antennas outside the fuse, brought frame losses to more acceptable levels.