RE: Just bought a DX7! First timer 2.4
its a solid TX... no complaints from my side... just to program you will have to scroll through step by step the manual unless you have someone with the same TX and could show you... I haven't touched my manual since I got mine in FEB this year... my friend did that for me and showed me... just from checking how he does things you can learn how to within a day... no issues... as a safety measure I always use full range receivers as I have lost park flyers using the short range receivers... AR6200, 7000, 7600 I use with the SE version...
receiver batteries will depend on the servos... but 6V 2200mah nimh is plenty... I do 10hours of flight time and there is still left... but then I charge them for good measure...