I just downloaded the manual for the 2100T, holy *&(^ what a useless piece of paper. I wish these chinese, japanese, korean (I am asian so there's no racism going on)... etc companies would pay the extra $100 to get somebody who actually speaks english to write these things. It might as well be in egyptian.

If that is actually the case you might be screwed, and based on what I could see of the manual it only supports Futaba and JR radios (you can probably use the JR setting for Spektrum). Anyway, if you can't get it to work you might have to ebay it and get a gy240 or gy401.

I'm assuming here that you replaced the standard tail servo with a digital one? the 2100T and GY240/401 work better with digital.