Patent ID: 7206558
Filing Date: 2007-04-17
Classification: H03J

Abstract:
1. A method of employing an audio subsystem for determining a tuning frequency of an audio receiver, wherein the audio subsystem comprises an audio signal generator for providing an audio signal, a detector for detecting a demodulated audio signal provided at an output of the audio receiver, a modulator coupled to the audio signal generator, the modulator providing a modulated audio signal that corresponds to the audio signal provided by the audio signal generator, and a processor coupled to the audio signal generator, the detector and the modulator, said method comprising the steps of: interrupting received radio frequency (RF) signals at an input of an audio receiver; injecting a modulated audio signal at the input of the audio receiver; determining whether a demodulated audio signal that corresponds to the modulated audio signal is present at an output of the audio receiver; and changing a frequency of the modulated audio signal when the demodulated audio signal is not present at the output of the audio receiver.