Methods and apparatus for selecting one or more suitable antennas for use during power-up/initial acquisition and out of service modes are disclosed. In some examples, initial system acquisition may be performed for a particular receive circuit utilizing a selected one of a first antenna or a second antenna, based on a channel characteristic, such as an automatic gain control (AGC) value corresponding to a received signal energy utilizing either of the antennas. In another example, initial system acquisition utilizing either a receive diversity determination algorithm or an antenna switching determination algorithm may be performed based on a channel characteristic, such as an AGC value corresponding to a received signal energy utilizing one of the antennas coupled to one of the receive circuits.