When using a Futaba and Hitec together, you must use the Hitec trainer cord and make sure that the master and slave side is correctly connected, i.e. master being the one controling the aircraft (receiver and transmitter on same frequency) and the slave being the other transmitter. Keep the power switch off on the slave and antenna down on the slave. If you were to try to use a Futaba trainer cord, both transmitters would be on even if you had the switch off on the Hitec trainer box. I'm assuming that you are using the Futaba as master and the Hiteck as slave.