Apple TV/FM Radio System - Manual (Page 68)

Choosing signal strength
By choosing a signal strength, you can set the Apple FM
Radio to seek or to automatically add stations that send
signals of a certain strength. For example, if you set the
signal strength to Strongest Only, the Apple FM Radio will
seek or automatically add fewer stations than if you had set
the signal strength to All Stations.
To choose the signal strength that the Apple FM Radio
application looks for when it seeks or adds stations, follow
these steps:
1 Open the Options menu and choose Signal Strength.
2 Choose the signal strength you want.
The signal strength you choose affects how many stations
come up when you use the Seek or Auto Add features.
61 Customizing the FM Radio Settings