I have the TH 9X channel transmitter, and the biggest problem I have with this remote is the most accurate way to change flight modes is by flicking one switch so whenever I want to change a flight mode I have to change flight mode 6 because flight mode 1 is always stabilize and simple mode, now this gets a bit irritating so one day someone posted a blog here of a potentiometer with 6 clicks and some variable resistors to each click on the potentiometer so you can define the PWM. I bought this for about $15 here and it was at my door in about 4 days, it was crazy. I bought the unsoldered version so I had to do some fine soldering.
Now the variable resistors has 3 legs (+) (Feedback) (-) it does not matter which way is the plus and minus. I took an old parallel cable from an old hard drive mounting and cut 6 strips from it about 10cm long and cleaned the plastic from it and soldered the two most outer wires from the bunch to the (+) and (-) and then Is soldered to all of the pins a piece of wire.
Once all that was done, I soldered the 4 inner wires to a number on the potentiometer, and the previous potentiometers brown wire where it said brown and the black to the black and red to the red. I then soldered the 2 most outer wires to the black and the red.
I then broke of the previous potentiometers plastic housing and drilled a bigger hole in the cover so that the new potentiometer can fit. Please note the extra smaller hole on the left hand side of the big one that I made, it is so that the new potentiometer fits snug into the hole.
I then fitted the nozzle thru the whole tightened it with a nut on the outside.
I then found a nice place to hot glue the variable resistors to the back of the cover so it is easy to come by with a screw driver because you have to adjust the variable resistors so that the signal is set to the correct PWM for the specific flight mode.
And then I started tuning the inner flight modes because the most outer two knob settings is always flight mode 1 and six and knob area 4 is also always flight mode 1. First set your aux-ch option to the following. Please note channel 5 is set to Pit trim.
I opened flight planner and started turning the variable resistors on each unit until the green on the dropdowns showed on the correct place.
An now I have 5 accurate flight modes to choose from without any hassle.
Hope it was help full and happy flying.