The Philestine wrote:
The unit was a Sangean WR-2 which was designed for table-top usage in the
home. It is a robust device, that includes PLL tuning, memory present,
external AMand FM antenna connections. What was most novel about the unit
was it's inclusion of RDS - Radio Data System - for stations in the FM band.
I had never heard of RDS before, and was fascinated to learn about this
intriguing option which provides analogue (and Digital) radio signals with a
complementary data stream which will display text information about the
station your listening to on a digital display dial for radios.
Don't feel too alone; RDS is not widely deployed in the USA either. I'd
say maybe 10% of American FM stations use it, and well under 1% of
receivers. It does make DXing a LOT easier, as here we have a scheme to
map a specific transmitter directly to a code transmitted in the RDS
stream. (though one major broadcaster has stopped observing that mapping)
AMSS is totally unheardof here. American stations have used a similar
modulation scheme in the past for closed-circuit signaling, for example
to remotely shut down consumers' water heaters during peak load periods.
I haven't heard anything about such use in a LONG time. I would
suppose AMSS would be mutually incompatible with AM stereo, not that
that would be a big problem with AM stereo pretty much obsolete.
designed for Analogue AM radio, although AM digital radio, such as is
available in Europe on the Digital Radio Mondiale (DRM) system, appears to
have AMSS and RDS functions as standard.
I'm sure Europe's Eureka 147 system (used on VHF/UHF) also has data
functions. In both cases it's not technically RDS but serves a similar
purpose.
Here in the States, we have (unfortunately) a digital radio system
called "IBOC", alternately "HD Radio". It contains provisions for
"Program Associated Data" which is the digital equivalent of AMSS/RDS.
A limited amount of data is available for MW IBOC stations - so far all
I've seen is display of the station name. (call letters)
Ironically, while only maybe 1% of analog receivers sold in the US can
receive the RDS transmissions of analog stations, in my experience 100%
of the new IBOC receivers can!
--
Doug Smith W9WI
Pleasant View (Nashville), TN EM66
http://www.w9wi.com