A receiver and associated methods are described. The receiver comprises a first oscillator 14, a second oscillator 16, a controller 18 operable to control frequencies to which the first and second oscillators are tuned, and a discrimination circuit 24 operable to receive and monitor transmitted signals; wherein the discrimination circuit is configured to receive a signal at a first transmission frequency determined based on a first tuned frequency to which the first oscillator is tuned, and to determine, in a capture time period, whether data is being transmitted at the first transmission frequency; wherein the controller is configured to tune, in a tuning time period, the second oscillator to a second tuned frequency; and wherein the tuning time period is shorter than the capture time period.