Patent ID: 7043211

Claim:
A modulator for combining a plurality of received signals and outputting a desired output signal, the modulator comprising: (a) a summing amplifier having a first input for receiving a video signal, a second input for receiving a first audio signal, a third input for receiving a second audio signal, and an output for outputting a modulated summed signal; (b) a first frequency synthesizer for generating a first frequency for mixing with the modulated summed signal to generate a high intermediate frequency (HI-IF) signal; (c) a second frequency synthesizer for generating a second frequency for mixing with the HI-IF signal to generate the desired output signal; (d) an audio mixer for receiving a baseband audio input signal and outputting the first audio signal to the second input of the summing amplifier; (e) a third frequency synthesizer electrically coupled to the audio mixer for generating a third frequency for mixing with the baseband audio input signal to generate the first audio signal; (f) a common communication bus, electrically coupled to the first, second and third synthesizers, for programming the first, second and third frequencies; and (g) a switch, electrically coupled to the common communication bus, for selectively providing the second audio signal to the third input of the summing amplifier.