A receiving device in a trunked radio communications system requests a voice channel for a communication and receives an outbound signaling message on a control channel comprising a voice channel number for the receiving device to utilize for the communication. The receiving device tunes to about a transmit frequency, wherein the transmit frequency is determined by multiplying the voice channel number by a channel spacing and adding a base frequency to yield the transmit frequency, if the voice channel number is between 0 and 119. The receiving device modulates the communication to about the transmit frequency and transmits the modulated communication with a transmit deviation that relates to a maximum of 4 kHz.