If you want to try and get ALL your surrounding channels having an antenna that gets you 360 like the chart below would good beginning. You could experiment with an attic install but you will have positioning / rotating limitations not to mention some signal loss.
Directly connect the cable / internet to the coax that has the modem, not splitter needed.
HOA might hassle you, make a good effort to place the antenna not near the front of you home. Yes there is an FCC Law that will guide an HOA.
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