RE: Spectrum buddy box question
I fly this combination at a school where I run a training class and yes, exactly as Alan says. It depends which system is installed in the plane itself which determins which Tx is Master or Slave. Your DX6 is 2.4Ghz and your JR's etc are probably on 35Mhz.
Be aware also that the DX6 is intended for "park" flying, with limited range.
As I am sure you know, it is also very important to "zero" the slave Tx controls before flying, and also to remove the xtal. This saves on battery drain as the Master Tx also supplys power to the slave Tx.
Happy Flying
CCM (England)