"Paul Vina" wrote in message
news:hmjVb.2329$QA2.12340@attbi_s52...
RDS is nothing but a second radio signal piggybacked onto the regular
signal
and contains whatever info the radio station sees fit to put out.

Well yes, that's partly true. But I think the major advantage of RDS is so
called AF flag which helps car radio to find the best channel frequency all
the time automatically. So basically you can drive 1000 miles and listen the
same (nation wide) radio station all the time without need to manually
adjust right MHz's. Also always correct time and date and radio station's
name is nice information on radio's screen. Sometimes you can see also the
name of artist and song currently playing. Facts about RDS you can find for
example he
http://www.radioandtelly.co.uk/rds.html
http://www.rds.org.uk/rds98/mainintroduction.htm

Pekka