I’m considering building a directional FM antenna for an FM station that has almost no signal in most of the house. Otherwise I must put the receiver near the window and put the antenna in a specific position. So now I wonder if I should also build a omni-directional FM antenna, and whether that would also suit DAB frequencies. Since I would prefer to only run one coax cable throughout the house I guess I need to know if the directional and omni-directional antennas can simply be spliced together to share the same coax.

It seems like when a station has both a DAB and FM signal, a smart receiver could theoretically compare a short sample of the digital sound to the same clip of the FM signal and work out what part of the analog signal is noise and use that to cancel out the static from the analog signal. Would that be science fiction or does that sound feasible?