I should have knows because of the tread....I used to do primary RX into B out 6 into RX1, secondary into A out 5 into RX2, and lately R3 900 into CB EXT set Receiver......and I never in a few year of using the CP had any problems...
But I was told by 2 different sources that it might not be the optimal solution because how the CP could fail and the way it operate....and understand that they are right...
So the way I’m hooking my latest plane is, Primary RX (RexR12) into B out 6 into RX 1 of the CB2***, Secondary RX (R3) into E2 of the Primary RX, R3 900 into the RX2 of the CB2***....
I have decided that I will not to change all the planes because some don’t have a R3 900, but if I need to redo some wiring at the same time I might do some of the change.