if I am listening to an FRS channel and I hear my neighbors talking, but they are using a "tone" so that they dont hear me, is that a Transmit tone, or a Receiving tone that is blocking them from hearing me? So.. if I am listening to them and I want to use my radio to scan for their tone to program it into my radio so they can hear me, what am i scanning for? R-CTSS or T-CTSS ?