What wireless transmitter?
Wixels work only for certain types of data transmissions and only for a limited number of radio frequencies in the 2.4 GHz band, usually those used by another Wixel.
The only difference between the unassembled Wixel and the fully-assembled Wixel is that the fully-assembled version comes with the header pins pre-soldered whereas the unassembled version comes with loose headers. Are you planning on using another Wixel as a wireless transmitter? If not, I am also curious what kind of wireless transmitter are you trying to use with the Wixel.