Adjacent channel interference

[kq6qv]

When the station you want is not receivable because of a much more powerful station in the next channel above or below, you have adjacent channel interference.

Before 1998, the FCC would never allow stations in the same city to occupy adjacent channels. (There were exceptions for channels 4-5, 6-7, and 13-14 because gaps exist between those channel pairs.) But due to improved receiver technology, the FCC now allows any channel assignment.

When a signal is 10 to 15 times more powerful than that of an adjacent channel station, most receivers become unable to receive the weaker station. To receive a far away station, you might need to use a directional antenna to reduce the strength of a nearby adjacent channel station. See