Let me pose this question as a hypothetical.
Your ship warps/jumps to a planet 50 light years away. You set up a radio signal receiver. Theoretically, the radio is going to receive radio-waves from Earth from 50 years ago.
My question is even with a powerful receiver, would the signal be clear enough that I could listen to 1968 radio stations without problems or would the signal have degraded to an almost undecipherable static? if so, what factors would be the cause of the degradation? Can gravitational or other interstellar phenomena (radiation?) degrade a radio signal?