Abstract: A TV decoder low loss switching system includes relay operated switch contacts for directly connecting an input signal without loss to a decoder tuner in the normal or enabled mode or bypassing the input signal to a TV in the bypass mode. The switch is parallelled by an impedance to permit a small amount signal singal to be applied to the tuner (in the bypass mode) for data purposes. In one embodiment, a second set of simultaneously actuated contacts connects the output of the decoder to the output terminal. In another embodiment, a channel 3/4 modulator is supplied by the decoder and its output connected via a PIN diode to the output terminal. The PIN diode is biased into conduction by actuation of a transistor switch responsive to the microprocessor enabling the decoder. The conduction of the PIN diode permits the channel 3/4 modulator signal to pass to the output terminal.