Operation London Bridge: the death of the Queen

The Radio Kent travel bulletins come in nice and clear when you're on the North Circular flyover going past Wembley!


That's what the AF switch is for, though as well as not getting the wrong programme, it will also stop you from changing to the right one when needed too

A very fascinating discussion. There's nothing like that here in the US except for satellite radio. If there's a song you like you can bookmark it and you get an alert allowing you to move to the channel before the song plays.

As for AM and FM stations the extent you get is maybe a station name and the song / program name. There are HD subchannels as a "multiplex" esqe offering different genres in digital quality.

Might be unrelated, but this is a pre-made report of footballer's Pele's obituary in case he is dead (a screenshot from a website of a Brazilian TV station):

Would be far from the first time an obituary's been posted in error!

Annoyingly, the radio I had a few years ago used to swap between Metro and TFM depending on signal strength. Back then, the schedules were different, so I could be listening to the TFM programme at 10pm, turn a corner and suddenly Alan Robson's Night Owls from Metro would kick in.

EDIT: Any idea why this happened?

There is an American standard for RDS: http://www.nrscstandards.org/SG/nrsc-4-B.pdf wonder why it never caught on

Wikipedia has a fairly comprehensive list.

Bringing the RDS chat back on topic, the spec has a Programme Type of Alarm, which would presumably interrupt CD play in the same way asa traffic report - though I doubt many stations have the ability to change PTY on the fly.

I guess because there are no national radio networks in the US, and the vast majority of stations only have a single transmitter, so really no use beyond station names and PTY ?

Yes. For example Wrotham (the main FM Tx that serves the South East), has a large coverage area,

http://tx.mb21.co.uk/gallery/wrotham/wrotham-map.jpg

So, in its EON TA table, it has to list:-

London, Surrey, Sussex, Kent, Essex, 3CR, Oxford, Berkshire.

Your radio doesn't know where you are, all it knows is when it receives an EON travel flag for a particular station, it attempts to tune to it, and if it's receivable, it switches over. Therefore if you're on top of a hill etc, you are likely to receive irrelevant travel news. Some radios have a sensitivity setting for travel news, that obviously eases this problem

There's switched PI, which Classic FM and some local stations with opt out transmitters use.

The PI code is switched during commercial breaks and opt outs, which effectively inhibits the AF function from working.
Classic FM have macro advertising regions, take a look at this spreadsheet, and you can see how the various macro regions are arranged. You can also see the same principle for some local stations.

https://www.ofcom.org.uk/__data/assets/excel_doc/0017/91304/TxParams.xls

I believe switched PI is not proper use of the RDS spec, so you'll never in a million years find the BBC using it, but it would have solved the Radio 1 nations issue mentioned by Steve.

One thing that I didn't know about for years was that RDS has RadioText (scrolling display that says what show is on or what is the current song). I always thought that this was a DAB feature until I got a car with a radio that had the ability to display it.

Am I right in saying that scrolling station names are banned as they could be distracting to drivers, but RadioText seemingly isn't. I know I've tuned into at least one pirate station that's used a scrolling station name.

Scrolling station names (PS Code) are not allowed for just that reason. (Didn't stop RTÉ doing it for a while) Radio Text is not supposed to be enabled (or enablable) on car radios, but my Peugeot audio system gloriously allows the text to be displayed, although many characters are not supported, and I get loads of hash tags and other randomness !