Alternative frequency (or AF) is an option that allows a receiver to re-tune to a different
frequency that provides the same station, when the first
signal becomes too weak (e.g. when moving out of range). This is often used in car
stereo systems, enabled by
Radio Data System (RDS), or the
U.S.
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territo ...
-based
Radio Broadcast Data System
Radio Data System (RDS) is a communications protocol standard for embedding small amounts of digital information in conventional FM broadcasting, FM radio broadcasts. RDS standardizes several types of information transmitted, including time, stat ...
(
RBDS
Radio Data System (RDS) is a communications protocol standard for embedding small amounts of digital information in conventional FM radio broadcasts. RDS standardizes several types of information transmitted, including time, station identificati ...
).
Radio technology
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