RDS-FM versus AM-SS - Data steam systems for radio
The Philestine
Last week I visited a major electrical department store that was staging a
closing-down sale.
I admit I was searching for a bargain, but I had left it too late since all
the good stuff I wanted was sold out - TVs, computers, 5.1 Surround Sound
systems etc.
Fortunately I did manage to find a nice china cabinet that was on sale at
half price. I knew my wife was keen to get a new piece of furniture, and
after sending her some pictures of it from my mobile phone camera, we
decided to buy it. So the trip to the store proved to be a good move.
I also came across a radio set that I had never seen before. It too was on
sale at half price and I very nearly bought it. The only thing that stopped
me was the fact that it appeared to not tune across the whole AM frequency
spectrum, which in Australia ranges from 522 Khz to 1602 Khz for the
commercial broadcast stations, and 1611 Khz to 1710 Khz for the mostly
narrowcast stations. Being an avid narrowcaster, I needed it to tune as high
as 1710 so that I could listen to the few narrowcast stations that operate
in the Extended AM band.
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.
I hesitated to buy the Sangean, but finding it has lead me to investigate a
whole new area of possibilities in radio. A little research on the internet
and at various electrical goods stores around town has revealed that RDS is
not widely implemented by commercial radio operators in Australia. Very few
stores that I visited had devices capable of decoding RDS information. I
guess it's a bit of a catch-22 situation - the big Australian commercial FM
stations hardly use RDS and therefore why should Hi-Fi and car audio shops
stock units that receive RDS signals?
Then I asked myself, is there an AM-Band equivalent for RDS? The answer I
found is YES, but it has a very limited deployment, being only used as far
as I know by the BBC. This AM system is simply called the AM Signalling
System or AMSS for short, and it is capable of providing a similar type and
quantity of data streams as RDS does for FM. You can click the links for
more techncial information on these topics, but I understand that AMSS is
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.
It is sad to me that these data systems for FM and even AM radio have not
been given the attention they should in Australia. I mention this because I
believe these systems add value to radio broadcasting that makes radio
listening much more user friendly for people operating in a TV saturated
age. But much needs to change in our regulatory environment before such
options become viable for church radio stations to implement. Narrowcast
radio stations in Australia are not likely to get permissions to migrate to
a digital platform for some time after the Commercial and Community stations
make their transition.
The Philistine
ausWY
> which in Australia ranges from 522 Khz to 1602 Khz for the
> commercial broadcast stations
I think the AM broadcast band starts at 531 in Australia, not 522.
> I hesitated to buy the Sangean, but finding it has lead me to investigate a
> whole new area of possibilities in radio. A little research on the internet
> and at various electrical goods stores around town has revealed that RDS is
> not widely implemented by commercial radio operators in Australia. Very few
> stores that I visited had devices capable of decoding RDS information. I
> guess it's a bit of a catch-22 situation - the big Australian commercial FM
> stations hardly use RDS and therefore why should Hi-Fi and car audio shops
> stock units that receive RDS signals?
I'm in Sydney and all of the Sydney commercial radio stations broadcast
RDS, from my location, I can receive the following RDS enabled frequencies:
088.3 - WSFM
095.3 - VEGA 953
096.1 - THE EDGE
096.5 - WAVE FM
096.9 - NOVA 969
099.1 - WSFM
101.7 - WSFM
104.1 - 2DAY FM
104.5 - STAR1045
104.9 - TRIPLE M
106.5 - MIX106.5
Additionally, with WSFM's three frequencies, they make use of the
alternate frequency (AF) feature of RDS, my car radio will automatically
choose the best received frequency. WSFM also broadcast with the traffic
programme (TP) tag. Some of the stations also broadcast artist/track
name, weather information, news, time, etc.
Triple J used to broadcast RDS but have since stopped.
I've seen various cars with RDS enabled systems, such as the Ford Focus,
my friend's Peugeot, the VW Golf, etc. My car's aftermarket Sony tuner
also has RDS capabilities.
Doug Smith W9WI
> 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
Larry Weil
news:45CB3BF...@invalid.invalid:
>
> 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!
>
In my experience with rental cars I have found that most GM cars have RDS
radios.
matt cook
> I've seen various cars with RDS enabled systems, such as the Ford Focus,
> my friend's Peugeot, the VW Golf, etc. My car's aftermarket Sony tuner
> also has RDS capabilities.
Pretty much all car radios from recent years are RDS compatible. It's
uncommon on home receivers though. LW reception is now also fairly
common on car stereos.
restore24-7
Stephan Grossklass
receive it came out 20 years ago (in 1987 - in terms of FM tuners, the
Grundig T9000 comes to mind), with first field tests having been carried
out starting in 1983 or so. By 1993 even the Japanese offered some RDS
equipped tuners, and that was about the time when it became pretty much
standard in car radios here.
In terms of shortwave portables, I can think of two models with RDS
decoding on FM - the Grundig Satellit 700 (1991-1997) and the Sangean
ATS-909 (1996-). One used to be able to buy aftermarket RDS decoding
units some time in the late '90s, but these have long been discontinued
and are now highly sought after.
Here in Germany, it would probably be fairly difficult to find an FM
station broadcasting without RDS, even our local noncommercial station
is transmitted with a station ID now. That it caught on here while the
US system RBDS still isn't very common probably has a lot to do with a
much more powerful and more centralized public broadcasting system at
the time (there weren't even any private radio stations until the
mid-'80s here). I know too little about the situation in Australia to
comment on that.
BTW, in the '90s a yet more fancy FM data broadcasting system was
developed (the SWIFT Eureka 1197 project), but apparently that never got
very far, although a matching Sony SRF-DR2000 receiver occasionally
makes an appearance on the 'bay.
While I'm reading this AMSS paper, I'm reminded of the time signal
information modulated onto some strong Frech LW broadcasting station.
That never really caught on, plain CW does allow much simpler receivers
and DCF77 seems to do plenty well enough here.
Stephan
--
Home: http://stephan.win31.de/
So if it receives like a handbag, does it sound good at least?
The Philestine
I too noticed when I played with the Sangean WR-2 that B105 in Brisbane uses
the Station ID function of RDS, but that is about it. It seems a pity that
it isn't more widely promoted and implemented, but when most car radios
don't have the functionality to decode RDS, why should stations do anything
more than broadcast a station ID? I just think it is a radio resource whose
time has come, and it is a pity that it is not more widely used in creative
ways. I would love to see the full RDS implementation working in Europe,
just to open my eyes to how it can really work.
I also have a Sangean ATS606 that I bought in Singapore in the 90s. Still
goes well enough. The more recent (and more expensive) models do include
RDS functions, and of course they tune up to 1710 Khz on AM.
I have been searching high and low for receivers that tune to the Extended
AM band, and it is very hard to find any that go all the way, and harder
still to find one that will tune to 1710 Khz in 9 KHz steps. JVC tuners
seem to go all the way up more often than most, and many Sony car radios
have a switch that will allow tuning in 10Khz steps. Portables with HF
tuning functionality normally will, and it seems the car stereos installed
by the manufacturer are often quite robust systems which seem to tune to
1710 (my radio in my Toyota Echo does), while the over the counter models
generally don't. For portables, you just have to go hunting at various
electonic shops for a model that will tune all the way - some do some don't.
Radio Brisvaani is a station I have tuned to many times (my wife is
Pakistani) and for this reason, among others, I want to tune all the way up
the AM dial. Being a narrowcast specialist, having convenient access to the
entire AM and FM band is important.
I haven't tried tuning to radio with a set-top box - that's also
interesting. But I have found a few DVD 5.1 sound amplifiers which include
a nice tuner that can tune across the whole AM and FM radio spectrum.
Someone needs to tell the gov't regulator ACMA to encourage manufacturers to
supply the market with devices that uses clever technological addtions (RDS)
and cover the higher frequencies on the AM band. If people could tune to
these Extended AM stations on their regular everyday radios, then operators
with NAS licences might start using their assets to provide interesting
services, and thereby enhance diversity in the marketplace. Radio Brisvaani
is a shining example of what can be done with a little effort, but any
Indian or Fijian who want to tune in more often than not has to go and buy a
new radio from DSE! We won't talk about World Audio!
Phil
"Stephan Grossklass" <sgrokla-n...@yahoo.de> wrote in message
news:eqn8qg$l02$00$1...@news.t-online.com...
The Philestine
I too noticed when I played with the Sangean WR-2 that B105 uses the Station
ID function of RDS, but that is about it. It seems a pity that it isn't
more widely promoted and implemented, but when most car radios don't have
the functionality to decode RDS, why should stations do anything more than
broadcast a station ID? I just think it is a radio resource whose time has
come, and it is a pity that it is not more widely used in creative ways.
I also have a Sangean ATS606 that I bought in Singapore in the 90s. Still
Phil
"Doug Smith W9WI" <w9...@invalid.invalid> wrote in message
news:45CB3BF...@invalid.invalid...
Shaun
If your in the Brisbane area tune into 94.9MHz. River has song title
streaming, and weather updates. If your Sangean WR-2 has RT (RadioText)
there is also latest news updates.
IT Admin is also working on some future software updates, so there is more
to come very soon.
Shaun.
"The Philestine" <phil...@tpg.com.au> wrote in message
news:45d1...@dnews.tpgi.com.au...
Rock in Stereo
RDS transmission?
I could be cynical but is this to confuse/mislead GC listeners into
believing that they are listening to Triple J?
Triple J in Brisbane also has the "alternate frequency" option enabled
like 2WS in Sydney has. Since AusWY has explained what the hell "AF"
is, the consequential scan that happens when I select Triple J all
makes sense now.
Leigh
matt cook
> Someone needs to tell the gov't regulator ACMA to encourage manufacturers to
> supply the market with devices that uses clever technological addtions (RDS)
> and cover the higher frequencies on the AM band. If people could tune to
> these Extended AM stations on their regular everyday radios, then operators
> with NAS licences might start using their assets to provide interesting
> services, and thereby enhance diversity in the marketplace. Radio Brisvaani
> is a shining example of what can be done with a little effort, but any
> Indian or Fijian who want to tune in more often than not has to go and buy a
> new radio from DSE! We won't talk about World Audio!
I've heard some minor players don't use RDS because allocating it
energy lessens the amount that can legally be used for the audio. The
power usage is the same, but the audio is a tiny bit quieter.
RDS decoding is pretty standard for car audio units from the last few
years at least.
As for what freqs a particular radio can receive, it's all down to the
market. If shops thought they could sell everyone a new radio or two
to listen to all the great new stations on the x-band, they would.
I've noticed an increased number of radios that can receive the audio
from the bottom of the TV band in Asian shops recently.