The Easy Trainer v2 I believe uses a Spektrum DSMX based receiver, and the TX12 does not support the DSM/DSMX protocols as it is delivered (you can add an external module if you really want the smaller TX12).
The TX16 does support the DSM/DSMX with its internal module, so it can be set up to work with the Spektrum based stuff out of the box. Peronally I run several DSMX models with my TX16s.