A wireless transmit-only apparatus (20) can be comprised of a controller (21) that selectively controls which of a plurality of resonant devices (24 and 25) are utilized to influence the transmission carrier frequency of a transmitter (26). In a preferred embodiment at least one of the resonant devices comprises a mechanically resonant device (24) such as a surface acoustic wave device, a crystal resonator, or a ceramic resonator. In a preferred embodiment, a user interface (22) includes a plurality of independently assertable inputs. The controller responds to assertion of one of this inputs by selecting a particular set of characterizing transmission parameters (as are stored, for example, in a memory (23) and using those characterizing transmission parameters to transmit a message using a transmission carrier frequency as corresponds to use of a co-selected resonant device.