Haven't tried it, but it should be fine. Different frequencies, both screened. Neither is high power. I'd say you were very unlucky if it doesn't work.
I can assure you that there will be no interference between the signals.
I have terrestrial input, satellite input, two RF outputs (to other tv's), a phone line, and mains supply power lead all bundled together leading to the tv/sat system in our lounge.
Until we got a new TV, there were also speaker outputs to a stereo system in the same bundle.