There is no decent answer to an ill framed question, and the question you have asked is ill framed. There are a whole bunch of factors that affect this. If we put a million watt beam antenna on the near side of moon and focus it on your town, and it is in your scanner's frequency range and uses a type of modulation your scanner can decipher then your scanner will certainly receive it. If we put the same transmitter on the far side of the moon it won't. Geography, power, type of antenna, location, receiver sensitivity, transmitter output power, the current state of the atmosphere including the weather will, all affect this (and I've probably omitted some other perfectly obvious factor). There are no "straight" shots anyway except over short distances because the earth itself is curved, and so forms it's own "mountain".
You want a simple answer to a question to a matter that is complex. As someone once said, "To every complex question there is an answer that is simple, elegant, persuasive, and wrong".