Emergency Broadcasts

Except FM can sometimes be a fuzzy, muffled mess. I find the constant changes in sound quality in FM more distracting in a vehicle than the constant quality of DAB (99.9% of the time).

Yep - RDS may have offered similar functionality, but it never really arrived or was implemented well on portable sets (it was really a car thing - as I suspect few people bought separate FM tuners for their HiFi with RDS, and how many people connect the aerials to their AVRs when the same stations are on DSat or DTT?)

Kitchen DAB radios have nice alphanumeric displays showing the station name, making it easy to find the station you want, the equivalent FM sets usually just had an analogue dial or digital frequency readout with no station name, radio text etc.


Yep - all my listening locations are well covered by DAB. Sure the sound quality isn't great - but for kitchen radio listening on a mono speaker it's good enough. If I listen in quality on my decent amp in the living room, then the 320k AAC stuff is better than FM IMO.


Yep - FM has never been brilliant in London - DAB is less prone to break up and interference in my experience (and no major pirate issues yet...)



Yep - snap.

The other big advantage of DAB is the SFNs - so that you don't have to retune national services wherever you are in the UK, as they are on single frequency networks - no need to retune (even in the background)

For the first time I now have DAB in my car and its frankly a revelation. I rarely suffer loss of signal, even driving from LoNdon to rural Gloucestershire on a regular basis. Not the Highlands or North Wales I grant you, but I was expecting the thing to switch to FM a darn sight more than it does. Sound quality for listening in the car is fine, better than FM IMO, as there's no fading or hissing. The one thing I find awkward is the station sorting, where (on my set at least) it's listed by multiplex, rather than alphabetically, so cycling through stations involves going back up through 'folders' from national to local mux.

At home, while I had a DAB portable set for a while, and even a DAB tuner for my separates HiFi, now all my radio listening is done through IP via a home streaming set up. Now that it supports the BBC HLS streams it's fine (though for about a year it was dreadful when the BBC switched from WMA streams to HLS, which a lot of streaming products like Sonos, Logitech and Naim couldn't receive, leaving a lousy MP3 stream as the only temporary stream available, which was unreliable to say the least.)

Back on topic, I happened upon a Panorama from 1980 which asks some questions about how prepared the UK was in terms of Civil Defence. It shows clips from Protect and Survive ("secret films that we've managed to get hold of") and mentions how four days before an expected attack these would be instructed to be shown on all television channels. Presented by a very youthful Jeremy Paxman, it's worth a watch.

Thing is that they're only in mono because there is an advantage to being in mono on DAB. Im sure that had there been on FM then stations could well have used it then.

In fact in a few instances there are/were mono FM transmissions, mainly in remote areas, though one London FM station was in mono for a while fairly recently when it's frequency was compromised

I got a plug in DAB receiver in the car a couple of years ago and once I got the aerial on a good location it's pretty good in most of my regular journeys. Mine does the same with the stations and has no presets which is annoying.

The big problem with mobile DAB is that sone/most sets don't rescan for new multiplexes automatically when they ever a new area.

I recently got a new phone/contract with 4G and tried in-car Internet radio and it surprised me how well it worked. Managed my very long, mostly rural commute with it only dropping out once. This was a low bit rate stream of TalkRadio though, how well it does with something meatier I keep meaning to try

Stereo on VHF / FM was pretty hissy when you didn't have a strong signal. Switching to mono almost always made the sound cleaner (if not rather defeating the point!)

For me the problem with DAB is the idea that it brings huge consumer choice - which was only possible by reducing bitrates and making some stations mono in order to cram more into the bandwidth available. Many very early adopters of DAB via HiFi separate Tuners were the sort of people who bought VHF HiFi tuners and had proper external aerials for them - so bought DAB ones too when they became available. Initially BBC Research and Development papers suggested that:
"A value of 256 kbit/s has been judged to provide a high quality stereo broadcast signal. However, a small reduction, to 224 kbit/s is often adequate, and in some cases it may be possible to accept a further reduction to 192 kbit/s, especially if redundancy in the stereo signal is exploited by a process of 'joint stereo' encoding (i.e. some sounds appearing at the centre of the stereo image need not be sent twice). At 192 kbit/s, it is relatively easy to hear imperfections in critical audio material."

I don't know whether Radio 3 was ever transmitted at 256k (I've a feeling it was at first), but it was 192 kbit/s until 2006, then reduced to 160 kbit/s prompting many complaints. While this decision was reversed, there are still times when it's reduced when extra stations are on the air.

Love Paxman's little line after the credits 'Well that'll send everyone to bed happy won't it?' Very interesting, A few bits from Threads seem to be lifted directly from this.


On the oft-quoted 'secret' nature of Protect & Survive, how secret actually was it? Many clips are shown on this documentary, many more were on threads, were there other examples of it being shown before being declassified? Also, although mass publication of the book never happened, it was available to order specially throughout wasn't it? ISTR that the inside cover of copies that do exist all state that 'it would be distributed free in the event of a real emergency but is being placed on sale now for interested parties' in order to justify that it had a price tag on the back!

How long did P&S last in the end? The films I think were all made around 1975, but were still current 10 years later during threads. Did it actually survive right up to 1991 when the cold war ended? Even later than that? And I wonder if anything newer (but likely just as useless) replaced it?

I think it was too.

You'll never get any DAB station using 256k, simply because the chipsets used in the vast majority of DAB receivers cannot support anything above 192k. I remember taking my 2003 model DAB receiver to Germany
that year, and all the 256k stations being silent on it

DAB+ is extremely robust for reception. The new national SDL service has a few DAB+ stations
on the mux, and in weak signal areas (of which there are many because SDL only have 45 transmitters, compared with the 400+ the BBC national mux uses) the DAB+ stations still hold together, where as you lose the vanilla DAB channels

I think Radio 3 is the last to have their bitrate cut in the event of extra programming. Radio 4 is regularly cut to 80kbps mono and Radio's 1, 2 and 6 Music have had it cut to 112kbps stereo. Radio 5 Live also has their bitrate cut from 80kbps to 64kbps mono. However the BBC's codecs are pretty good with low bitrates when they have to reduce them from 128.

For those interested, there is a licence requirement in broadcast licences to comply with any direction given by the Secretary of State. This applies under section 336 of the Communications Act, where the Secretary of State directs Ofcom to service a notice directing the licensees to broadcast something specific. There is not record of this being used to date.

In The Netherlands, the country I live in, the government can ‘seize’ airtime on radio and television channels. Of course, this power is in a democracy only used in case of events of high importance. As far as I know, it has been used at least one time: for a speech by the Prime Minister in the 1970s on the oil crisis (when NL was cut off Arab oil). It may have been used as well for the abdication speech by Queen Juliana in 1980 and Queen Beatrix in 2013, but I’m not sure.

In case of emergency, the emergency broadcasts are carried out by one (or more) of the 13 regional broadcasters, in case of a fire or flooding for instance. In an official contract between the broadcasters and the emergency services, rules are set out. For instance, when the broadcaster receives a call from the authorities, the broadcaster has to verify the command with the authorities. A verification fax will be send by the authorities before emergency broadcasts start. The authorities can issue a statement which will have to be broadcast on radio, television and online.

During the Cold War, three emergency studios existed: one in Hilversum (the seat of Dutch radio and television), one in Lopik (just under the biggest FM transmitter) and one in the government’s emergency seat in The Hague. As far as I could find, only the Hilversum studios are fully operational.

That it is important to spread the venues, became clear in 2015, when an “armed man” (later he turned out to bear a fake gun) entered the buildings of the national broadcaster NOS to read a message on the main evening news. Since the entire building, including the MCR, was evacuated, no broadcasts could be made from there. One man hided from the police services and went on working in the MCR, so the television services could resume from the parliamentary studio in The Hague. (Side note: a press conference from the mayor of Hilversum, just a few kilometers outside the Mediapark, was transmitted on Dutch tv via the VRT in Belgium and the little parliament studio in The Hague).

For the local broadcaster I work for, we only have a scenario ready in case of the decease of a member of the royal family, an emergency scenario named ‘Dossier Orange’

Was there one sort of emergency broadcast when there was that big firework factory fire in the Netherlands a few years ago? I remember they pulled out of the Eurovision Song Contest that night to cover it.