OK, turns out I don't have FMS on my PC anylonger, but the USB to Futaba TX calibration program was.

Here is what happed with my 10C which I put the 2.4 module into before starting.

When I plugged the sim cable into the TX, the tx powered on but without RF showing, The screen show PCMmode. When I started the calibration program, stuff was flashing and blinking, just like it does in PCMmode. I went to Pramaters and changed to PPMmode, pulled the cable and the put it back in. Istarted the calibration program again and this time I could calibrate the sticks, knobs and switches.

I then pulled the cable and powered on again and this time It came up in 2.4 mode. I powered off an pluged the cable back in and it powered on to PPMmode again, even with the 2.4 module in, still the RFwas off.

SO, for my 10C, Ican use it eithere with a 72 module or a 2.4 module, or no module at all. It will be curious to see what happens when you plug the USB cable into the buddy box port on your TX as it is a 2.4 only TX. See if it shows the mode on the screen then, Best way to tell though is to start the calibradion program and see if you can move the stick on the screen,and see if the display isis jumping/flickering around.

I'm not going to be able to test in your environment.

Don