An RF modulator/switch selectably couples a locally generated and conducted RF
signal or an antenna RF signal to a broadcast radio receiver. A local RF input
receives the conducted RF signal. An antenna RF input receives the antenna RF signal
in response to a radiated RF broadcast in a broadcast band. A resonant network
has a first node coupled to the antenna RF input and has a resonant frequency corresponding
to the broadcast band. A first relay has a first output selectably coupled to either
the antenna RF input or a second node of the resonant network. A second relay has
a second output selectably coupled to either the local RF input or the first output
of the first relay. When the second relay selects the local RF input then the first
relay selects the second node of the resonant network and when the second relay
selects the first output of the first relay then the first relay selects the antenna
RF input.
