Does anyone know of a way to test the tx module's on these? I have one that will only work (or so it seems) with a spectrum 2.4ghx module, but not with the standard FM module they come with. I bought a new FM module on ebay and that one didn't work either. I guess it's possible I have two bad modules but it seems unlikely. Has anyone run into this before? I bought this M11 online as well so I never knew if it worked in the first place with the FM transmitter module. Anyone have a known working one they could sell me? Thanks!