If you have not, then the mark is not active. Because Transistor fm has used their mark in commerce, then they will hold rights to it already even if they have not officially trademarked (not sure if this is so). So a useful way to handle this is to quickly make your first sale if you're trademarking something new (and issue an invoice).

They can also contest your mark during the trademarking process.

The above is the way it works in the US; not sure about other countries.