Automatic sensing RF combiner

An automatic RF combiner receives signals from an over-the-air antenna, a cable television signal source and at least one satellite antenna, and combines the signals for output to one or more television receivers. The combiner includes a first signal combiner connected to the input for the over-the-air antenna and the cable television signal source and providing an output signal. The output from the first signal combiner is supplied to a second signal combiner together with signal at the input for the at least one satellite antenna. A switch or filter is connected between the input for the over-the-air antenna and the first signal combiner, and a logic controller is connected between the input for the cable television signal source and the switch or filter that is configured and operable to open the switch or activate the filter when a signal is detected at the input for the cable television signal source, and to close the switch or deactivate the filter when no signal is detected, thereby controlling whether the over-the-air signal passes to the first signal combiner.