Halfords invents radio signals that don't travel at the speed of light Halfords is telling potential DAB radio buyers that the digital radio tech is "super-fast" compared to analogue AM radio, which might come as a surprise to the laws of physics. The car accessories retailer is trying, like all good businesses do, to drum up interest in its DAB digital radio sets. To this end it published a …
As I recall, there's always a noticeable lag between FM and DAB - with the audio arriving on FM before that of DAB - probably due to the processing chain in going from the analog broadcast world to the digital broadcast world. Not entirely sure what causes it beyond a few instants for A to D conversion
probably due to the processing chain in going from the analog broadcast world to the digital broadcast world
I suspect that the delays are more likely to be caused by the acceleration and deceleration of the DAB radio waves as they leave the transmitter and enter the receiver. Either that or the FM radio wave supply chain has introduced efficiencies in an effort to stave off the mooted shutdown
It's affected differently by different devices too.
I have a VQ Christie in the lounge, and a Pure Bug (anyone remember them?? * ) in the kitchen (the rooms are abutting). The Pure Bug outputs it's audio about 3 or 4 seconds later than the Christie. NOt sure if it's purely because the Bug is > 10 years older, or it has more error processing. The sound quality appears to be comparable.
* It was a gift, that's my defense, and I'm sticking to it.
Rock Burner,
I hate you! My Bug died this year, after nearly 20 years of long and happy service. It winked at me every night when I went to bed, and then opened it's eyes every morning (well every time I turned it on actually).
I now have to pick up my stupid bedside radio to work out what the fuck is happening when I try to tune it. Why do all DAB radios have such pisspoor user interfaces? And such tiny screens. They only seem to give you 2 buttons, with each doing 20 different roles, depending on how they feel, or how hard you press them, or whether you're looking at the screen or not when you press it - and if not they'll sneakily come up with a 21st function, to do a complete re-scan of all stations and re-set.
Whereas the Bug has that nice big screen on a flexible metal stand, that you can pull towards you in bed, and lots of buttons so it's not horrible to use. Admittedly I paid about £90 for mine, and the modern ones are more like £20-£30. But that and my Motorola RAZR (also from about 2003) are 2 of the best tech purchases I ever made.
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I've got an original white Bug which I bought soon after they came out in (I think) 2004 and use it every day. The audio outputs at virtually the same time as my other DAB radios - it just sounds like there's a slight echo when you listen to two together.
The only problem I experience is that sometimes when you use the sleep timer it freezes when it turns off meaning the alarm won't come on in the morning. I've got a separate travel alarm clock to save me in case this happens.
I've updated mine with the v2.2 software (Menu > General Setup > Software version) which gives you the EPG function. The way it stops you turning on or off, changing volume or stations while saving EPG data to the SD card is a bit annoying but I found the smaller the SD card, the quicker it completes this so I bought an old 16MB one from eBay. BBC Sounds renders the recording function redundant for me so I haven't needed the SD card capacity for recordings for many years.
Why do all DAB radios have such pisspoor user interfaces?
I hate to break it to you...but it seems to be a growing trend...and it's not restricted to DAB radios :-)
Maybe because the UIs are designed by Chinese who don't give a sh*t as long as they make money?
Sad, but true. The last good UI I saw was on a Nokia phone in the 90s.
Technically it's the lovely Ivana's oven but...
The old oven had two knobs and some push-buttons - easy as pie to use.
The new one has two knobs and a baffling touchscreen that isn't wide enough to display its messages so they scroll by much worse than the messages on a London Overground train.
It's taken her 3 months to get the hang of it and produce reasonably consistent results.
And don't get me started on the controller for the underfloor-heating.
"Maybe because the UIs are designed by Chinese who don't give a sh*t "
It's actually more likely due to at least one generation of UI "designers" (regardless of nationality) that never heard of ergonomics but are convinced they're the most brilliant artistic guys that ever lived.
In a vacuum. Which is likely not the condition of the atmosphere (ok, there is an atmosphere, so it is no vacuum...) over the UK - despite you having a bunch of air thieves that wrote that drivel....
Re: signal quality. Head over to youtube and search for Mat's channel (techmoan) and look up the video he did on DAB (tl;dw; low bitrate to cram more stations into fewer channels -> audio quality is shite).
The speed of light is defined (!) to be exactly 299792458 m/s because the meter and the second are defined quantities.
That said, the British are probably going to enjoy this increased speed in short time, in contrast to the usual slight speed reduction caused by air. The British isles are already known for low pressure coming from the west. Then at brexit time, the EU will turn off the flow of air too, reducing the air pressure considerably and speeding up any radio signals in the process.
BTW, you know what happens, every time a politician creates a pocket of high pressure air? Well, the speed of light through that medium is reduced, which means time slows down! Therefore, politicians can never reach their full potential; the more they try, the slower they get.
The second is defined in relation to a specifix caesium emission isn't it. Then the metre is defined as a number of wavelengths of one of the sodium lines?
So the speed (in a vacuum) is absolutely fixed, because the speed defines the metre.
And radio waves travel at that speed, not near as dammit - actually at.
Of course that speed is modified by the transmission medium.
My radio seldom goes further than 1500m - which is far enough for anyone - so the difference is probably negligible.
Didn't Captain Scarlet have an issue with radios being 1500m from source?
(The only link I can find to anything related to the episode https://www.youtube.com/watch?v=k8RsdDEWAy8 , sorry its not the episode itself).
There's probably a radio joke to be made here about Spectrum, but does that apply to DAB?
Yes, Captain Blue had been bashed on the noggin. He could hear the Big Ben whilst he was still groggy, but heard thirteen chimes. They worked out that he was hearing the chimes directly and via a radio and were able to calculate how far he was from the Houses of Parliament.
Of course, that wouldn't work with DAB because of the delays associated with audio compression, interleaving, FEC and variable decoding times in different receivers. Another cherished childhood memory ruined by the relentless march of progress! When was the last time physics was used/referenced in a kids' TV show?
Older viewers will recall the "O"-level Physics question about whether the chap on Westminster Bridge hears the chimes before or after someone in Australia listening to the World Service.
Surely radio waves travel at the speed of sound? Whereas the magical digital DAB stuff is doing light. But like the tortoise and the hare - it's showing off by running in circles round the chips. Plus it's got to go off to somewhere to find that weird underwater popping noise that only DAB makes - I reckon there are giant bubblewrap farms in the arctic - and it's going there that takes all the extra time and so is why analogue signals are quicker.
The advantage of the DAB delay is that it often matches the TV delay - so you can have the radio commentary when watching sport. Not possible with analogue, as that tells you what happens beforehand.
I usually take a small Roberts Test Match Special radio when I go to a test match. TMS fills in gaps without any noticeable delay.
One time I mistakenly took a small DAB radio instead of the trusty Roberts. An example to highlight the delay: the batsmen were just starting their return run when the radio had the sound of the ball on bat before they even started their first run.
Icon - because that's what you have during a match.
FlossyThePig,
Beer is all very well during the match - but if you go to Lords you're still allowed to take in 4 cans, or one bottle of wine per person. No other Test grounds let you - due to ICC awfulness, but Lords told them to get stuffed.
A buttered baguette, a bottle of bubbles a load of smoked salmon should sort you out for lunch. Then pork pies, various cakes and crisps will do for tea. And snacks during - sport can be very tiring... All of which goes nicely with some beer from the bar. Or, if you pack your picnic carefully - security don't tend to want to interfere with your sarnies - you can easily hide a flask of gin and some tonic in there. Which is perfect - you need lemon/lime to go with the salmon, and the rest can go in your teatime G&Ts.
Add a radio for TMS and some waterproof clothing, and you're sorted.
Radio waves do indeed travel at the speed of sound which is why "audiophiles" have been known to spend so much time balancing the lengths of their speaker cables ... or buying super expensive, pre-terminated, accurately length matched, oxygen free, silver coated cables ... doh!
yeah, and obviously a physics constant.
The quote in the article suggests that he should have said BANDWIDTH [for the modulation] and not "super-fast wavelength" implying "speed", but people who don't understand modulation won't get it, probably. [People in here probably WILL get it]
Whenever you modulate a carrier, you generate frequencies that are equal to the modulation frequency[ies] plus or minus the carrier frequency. In the case of FM, FSK, QAM, and other modulation methods, you have to include harmonics as well, and in theory, the harmonic output goes out to 'infinity' in both directions around the carrier frequency. [in practice it's limited by filters]..
16khz bandwidth (+/- 8khz) would be typical for an AM broadcast, up to ~8khz audio freq in the modulation. This gives you reasonable quality audio, good for voice [hence news/talk formats typical on AM].
+/- 75Khz bandwidth is typical for a wide-band FM broadcast. A total bandwidth of 75khz would have too much harmonic distortion (think 'missing information'). In the USA, there is a 200khz 'in between' frequency range between stations to allow for sufficient bandwdth without side-channel interference.
for QAM and FSK and spread spectrum and other digital modulation methods, you have a much higher bandwidth requirement, and 'frequency hopping', and things like that. Wifi, cell phones, digital radio and TV signals, all use something _like_ this. And of course, their bandwidth is in Mhz and not Khz, and can take up a pretty big chunk of the available spectrum. Hence, it's transmitted in the Ghz range where this kind of thing makes more sense.
Anyway, what the quoted marketeer was apparently TRYING to say is that wider BANDWIDTH means you can transmit MORE DATA at a higher DATA RATE.
but yeah he got it wrong in the details, concepts, and presentation.
While this clearly is marketing BS there is a certain truth to it. It depends how you define "fast". DAB has a higher bandwidth, so can transfer more data more quickly than a lower bandwidth analogue FM, transferring the same amount of data more quickly is arguably a reasonable definition of the word fast.
Before you argue that this isn't the case, consider whether two broadband connections that can both get 1ms latency to a server, but one is 24Mbps and is 36Mbps can one be said to be "faster" than the other or not.
It is not faster (in the physics sense). The signal (the ones and zeroes) travels at the same speed. There are just more of those ones and zeroes per second. The bit rate is higher...
Speed is distance divided by time. The amount you carry does not factor in. Example: two cyclists, one solo, the other with panniers and a trailer with two kids in both riding along at an easy 25 km/h. It will take them an hour to cover the 25 km to the next playground (kids in the trailer, remember?) if there are no traffic lights and no steep climbs. Both arrive at the same time. You would argue that the one carrying the kids would be faster - which is clearly not the case. That one had to work harder than the other, but they had the same speed.
"It is not faster (in the physics sense). "
But the description in question is not a physics lesson. It's trying to describe how digital radio works. It's not done very well, but I think suggestions that they are trying to claim some radio waves travel faster than others is missing the point.
It's worth keeping in mind that when it comes to the quantum world of particles, just about any explanation we use about how things work is based on simplified models that we, in the macro world, can understand. All these models have limitations where they break-down and can be picked apart. Halford's attempt at an explanation is no different.
If a frequency is defined as the number of oscillations, then DAB is "faster", in that it has more oscillations (if a shopping basket packing race, it would "win" and be faster at packing the shopping bags).
While not completely detailed, their explanation was not "wrong", it just focused on the speed of data delivery in total, not the speed of the signal propagation or delivery of a single bit.
> "It is not faster (in the physics sense)."
Yes, but- to play devil's advocate- we use terms like "fast broadband" in that non-literal sense so often that no one even notices it, lets alone thinks to complain.
"Fast" in that context does make sense in that you can download files faster, but it's still a synonym for bandwidth rather than literal speed.
You could argue that such usage of "fast" doesn't make sense in terms of streaming (which is what digital radio effectively is) or that the comparison with analogue radio was meaningless and/or incorrect (given the quality issues). However, if one's going to argue against it on the basis that such usage is contrary to physics, we should at least acknowledge that we're (apparently) okay with that in other contexts.
True that DAB+ uses better AAC compression, but it's also not backward compatible with DAB only receivers. Fine if you're operating a commercial multiplex and want "more stations" over "sound quality" and don't care that it rules out a few older receivers from your TAM; but not much good for things like the BBC National Multiplex which sticks with DAB operation (and it's crappy MP2 compression) because if they switched to DAB+ there'd be a lot of older DAB receivers that would be immediately obsolete. This is the problem of being an early adopter on this tech. Other countries, like Norway, who adopted DAB later, have gone exclusively DAB+.
When you consider limits and differentiation, an analogue signal can be measured as limits as it approaches a particular point in time and how close this approach comes is virtually infinite and there is no digital system that can transmit a signal with that much information.
Even though the extra information is superfluous for any audio entertainment purpose, it's still more.
Some sort of of politics to suit the national broadcaster was why they switched off FM.
Other countries have switched off DAB, or will never start it.
Ireland's National DAB only has RTE on it, and is 46% to 55% coverage depending who you believe, but useless for intercity travel. It is 128k or 64k (depending on station) mp2, too poor quality and coverage.
RTE are going to turn DAB off shortly.
DAB, especially SFN, also is ill-suited for local or community stations. FM serves better. Full national coverage needs AM! Hence R4 LW, RTE1 LW and Five Live on MW.
It turns out that DAB needs about twice as many masts, though lower power, than was planned just to match FM coverage on portables. FM in UK still not as good coverage as the big MW and LW Transmitters on AM.
Why are there no DAB pirates? The gear isn't actually very expensive. Use a PC based card / adapter sold for testing DAB receivers and a nice linear amp in the 200MHz band.
Because almost all DAB sets have FM. Many phones have FM. An FM radio starts at £2 and decent one is easier to use than a DAB set, sounds better, more range and x5 to x20 battery life.
Many DAB sets are used on FM. So called "Digital Radio" figures add DAB sets, DTT listening, Sat listening, Internet streaming.
Niche stations, especially national, are cheaper to do on the Internet and coverage on Mobile is better than DAB!
My phone has no FM :( my last one did. The argument is you can just use internet radio, yes, the same internet radio that eats battery faster, uses chargeable data and wont work where you have poor cell coverage. Sigh.
Partly I think it's the move to bluetooth, as portable receivers typically use the headphone cable as an antenna. And partly analogue tuning and searching for stations (even with auto-tuning) probably doesn't appeal to those who like clicking on an icon.
I came here to say this. I know - and takepart in the pedantry here at el reg - but it's obvious someone has tried to take the concept of "higher frequency radio allows data to be transferred at a higher rate" and translate it into non-technical language.
it's like all science teaching: "lies for children" it gets the basic concept across. If someone's interested, they can can learn more later.
Maybe if we did try the truth, we might progress faster?
This. People don't have a problem with the truth, if starting from the start and young. It's only as we get older (even from a young age), that all the social "lies" get in the way (of the reality/functional/engineering/maths, the social side is fine and great and needed, but should not change facts or math!).
Like most languages, it's harder to "unlearn" the errors and mistakes, than learn new and afresh to begin with. Or programming, if starting early, compared to having to learn it much much later on.
I've waded in at the deep end with some topics for my kids.
We've covered orbital mechanics with much success and kerballing. Covalent bonding was pretty good too, using Lego as an analogy. AC vs DC electricity, with voltage vs current was okay too.
Of course, all these are superseded by discussions of Nintendo vs Sega, and why Nintendo were crazy (but ultimately justified) in making the N64 a cartridge console, 13 years before my kids were born. There's only so far you can go before their attention goes elsewhere...
Edit - to be clear, my kids steer the conversation to old consoles, not me!
I think it applies to pretty much all teaching. I still get it with the dance lessons (oi! no sniggering at the back!), where the teacher explains how to do a particular step for the first time then, as we progress ,months or years later, you get "Well I said that was how to do it, but actually it should be done more like this, that's just the simpler explanation to start with" and now you have to not just learn how to do it correctly, but unlearn how to do it wrongly first! Gah!
...it's like all science teaching: "lies for children" it gets the basic concept across...
When I was ~14 I made the huge error of raising my hand when my physics teacher said something about spaceships heating on re-entry due to friction, and politely asking if it wasn't due to compression instead.
I promise I won't do it again!
8^)
No, it doesn't even do that. It's worse nonsense than ST-TNG technobabble.
Also DAB as implemented actually uses low bitrate per channel. Any VHF frequency from 42MHz to 275 MHz could do DECENT quality Digital Radio OR FM.
Some FM / AM sets sold today for the world market actually do 64 to 108MHz to suit old East European, Japanese, Western Europe and USA. They don't usually do LW now because that wasn't used except in Europe, North Africa and Russian Asia. Some older ones do have LW and also 42 MHz to 275MHz in several bands, possibly for marine, ham, US Weather and also Analogue TV sound in USA (and parts of Europe till about 10 years ago) as well as Japan and Eastern Europe.
DAB was too early and thinking behind it is now outdated with streaming for niche content. FM and AM are actually better for national mainstream radio and local/regional/community mass market radio. Far far more efficient for receivers, more robust, and FM in many phones (the WiFi & BT chip has it built in for free)
DAB might have higher bandwidth but a significant chunk of it is used for the FEC. More than 20KHz bandwidth is pointless and if you're over 30 then significantly lower than this due to hearing loss at high frequencies.
In practise many DAB stations, including music stations, reduce the bandwidth significantly, or have it reduced for them in order to cram more channels into the available spectrum.
While this clearly is marketing BS there is a certain truth to it. It depends how you define "fast". DAB has a higher bandwidth, so can transfer more data more quickly than a lower bandwidth analogue FM, transferring the same amount of data more quickly is arguably a reasonable definition of the word fast.
No.
It would be fair to say that DAB has a higher bitrate and can therefore receive better quality audio. This irrespective of the fact that most radios don't claim to be hifi's, and that most hifi's do not offer high fidelity reproduction of the signal input these days, and that a goodly number of DAB radios are in cars with such high ambient noise from the road that any sound improvement is drowned out and unnoticeable. That one can accept as normal marketing bullshit.
But it's still not faster; both play a 3 minute bit of music in 3 minutes. Arguably, DAB is slower because it takes time to buffer etc from the start of a transmission.
I believe the argument is more: it could push bits faster and more bits means higher quality. Which would be good if they actually used more bits on each channel instead of actually using less bits per channel across far too many of them!
I'll stick to high bitrate internet radio on my av amp/Kodi boxes/pc. Never heard a dab channel that didn't hurt my ears.
DAB has lower bandwidth, bandwidth being literally the width of the band. It may make more efficient use of that bandwidth in achieving a given audio quality, but it's lower bandwidth. You cannot transmit a signal with a single frequency, you need a range of them, hence bands. At higher carrier frequencies there is obviously more space to pack the same bandwidth in, and DAB does that, but there's also strong competition in those ranges from other use.
Analogue FM, 200kHz per channel.
DAB multiplex, ~1,500kHz, about 10 channels per multiplex => 150kHz per channel.
https://en.wikipedia.org/wiki/Digital_Audio_Broadcasting#DAB_and_AM/FM_compared
Bitrate and bandwidth are not the same thing except in colloquial use.
They will have a hard time finding all the FM radios I have. They are embedded in almost everything.
And if they do nab them all, I'll just hide away my Sinclair X1 Button Radio. MWHAHAHAHA
Also my single DAB radio (thats portable at least) has a hard time decoding anything if the antenna is not in the correct position and extended far enough. Its a nice radio, cheap from amazon, records to micro SD and runs of a 18650 lithium battery that is charges via micro USB.
Whilst the higher frequency used by DAB may allow transmission of data faster than the lower frequency analogue FM, all the digital processing (both sender & receiver) has a speed impact. Hence why, as others have mentioned, the pips on DAB are later than on FM. It's the same reason why the BBC no longer has an analogue clock showing the second hand before the news: Analogue viewers see it before digital. (And on Freesat, HD is even slower than SD - by several seconds)
There's no analogue TV in the UK anymore, the reason the second hand was dropped is the time delay between Freeview SD, Freeview HD, Sky and cable, all 4 services would show a different time, and all 4 would be wrong by at least a couple of seconds, possibly more.
FM is real time, as near as makes very little difference, DAB is out by at least a few seconds, and BBC Sounds App can be up to 30 seconds late, so if you miss an important wicket on TMS you just log into BBC Sounds and hear it again...
> Whilst the higher frequency used by DAB may allow transmission of data faster than the lower frequency analogue FM,
No, you can do it with shortwave but I think you are referring to bandwidth which would be greater than the lower frequencies but that just lest you pack more stations in (if only they didnt do that, DAB might sound god and even be in stereo). The higher frequency was used because its very localised so that you can cover the nation and find it easier to avoid overlap. Also the spectrum was available.
That hertz.
Apart from that particular bit of nonsense, they're mentioning 75kHz for FM *and* AM. That'd be even lower than the DCF77 signal. Even if they'd mean 75MHz (with DAB transmission frequencies being 200..230MHz that might make a little more sense) that frequency has no relation to either FM (88-108MHz, 10.7MHz IF) or AM (150kHz to 30MHz or so, 455kHz IF) broadcasts.
Though it's wholly in line with the "technical expertise" I got to experience at Halfords.
In the last 10 years or so I've come across a couple of Mercedes car radios that support 49m shortwave. Presumably, normally fitted to their cars that go to Africa or somewhere. Both had very poor reception in the UK, presumably as the antenna fitted here does not match well at 6Mhz.
I've no idea if all MB have SW, or just a small number of basic models.
75Khz is the deviation of FM signals from their nominal carrier frequency when fully modulated.
Lord knows why Halfords decided to put that into their spiel..... It has no relevance whatsoever, unless you are comparing the audio quality of broadcast FM with 2-way radio type FM, which has a deviation of around 5Khz.
As everyone knows, the frequency of FM broadcast is 88-108 in most of the world, and Am broadcast around 530-1600Khz, except for the aforementioned 1500 metres in old money.
DAB of course could be broadcast on pretty much any frequency - it's just that the Band 3 frequencies around 200Mhz are fairly well suited to this, plus, in the UK, there were pretty much available for use from the late 80's onwards.
Audio quality better than AM or FM? Er, has the capability to be so, but in practice is not implemented. Arguably good AM sounds much better than 64kb/s MP2.
"What's the modulation method got to do with the frequency used?"
Quite a lot - I worked (until very recently) with systems that carried multiple wavelengths on a single fibre bearer - 10 years ago I was working with 10Gb/s systems using 100GhZ spacing of the carrier frequencies (Mach-Zender modulators, simple on/off keying of the carrier) - when I retired 3 weeks ago, I was working with DPQPSK (Dual Polarization Phase Shift Keying) systems that will do up to 520Gb/s at 50GHz spacing of the carrier frequencies - and the distance between regenerators (as opposed to amplifiers) has gone from 100s of Kms to 1000s of Km.
The money now days is in developing better modulation and error correction protocols - demanding more bandwidth for higher bitrates very much labels you as an 'also ran'.
"It's also fscking useless in a moving vehicle."
In the UK outside London, yes. I drove through Norway in the summer, with perfect DAB reception everywhere apart from in 2 of the longer tunnels (16 km and 25 km). Once you cross into Sweden the familiar DAB silences reappear.
I drive a wide variety of hire cars on a regular basis, mostly in the North West UK, so well outside London. What makes most difference to cutting out is the car manufacturer - Hyundai are about the worst, followed by Mercedes Benze & Vauxhall - on a regular trip I do VWs don't lose signal anywhere whereas Hyundai there are 4 "not spots" on the route.
So maybe the finger needs pointing at the vehicle manufacturer as well as the broadcaster mechanism.
"So maybe the finger needs pointing at the vehicle manufacturer as well as the broadcaster mechanism."
I drive around most of the NE and NW and listen to Radio4Extra much of the time, pretty much without issue. My additional data point for your survey is that I drive a Kia. I don't get hire cars often enough to offer any additional data points.
Because they spent a fortune on DAB masts. More than anywhere else. And turned off FM.
It's almost certainly political to benefit NRK.
DAB most benefits National stations with multiple channels. Also car and table top radios, bad for portables.
It certainly wasn't done to give higher quality or save money. You also need a power hungry DAB+ receiver, so not great for portables. Phones with DAB+ rather than FM are rare or non-existent.
"who actually listens"
Millions and millions of people. 7.1 million people in the UK listen to any podcast. That's less than the listening figures BBC Radio 1 alone. 88% of the UK listen to live radio.
It's always amusing when someone, keen to impress everyone with their uptake of newer technologies, feign ignorance that everyone isn't the same as them.
It doesn't even make sense. If I jump in the car and drive to the shop, I don't want to fanny about with my phone finding a podcast to listen to a few minutes of.
I stick the radio on and listen to one of about four stations (unless England are playing and I'll stick TMS on ).
The vast majority of people do that.
( Although if anybody can recommend a decent Rugby Union podcast, it would be appreciated )
Although if anybody can recommend a decent Rugby Union podcast, it would be appreciated
Brian Moore does one (sponsored by the Torygraph). It's a bit short, given how much there is to cover - and it's got Brian Moore in it - and I get the impression some people don't like him. Whereas I do. And it mostly covers international, European level and English Premier rugby. But it's worth a listen - and he often has good guests.
> Plus who actually listens to broadcast media in these days of on demand podcasts, Spotify and other streaming music, and audio books?
People who want to listen to stuff thats happening live and if it is a pre-recorded show, those who want to avoid binging episode after episode as they get fatter and fatter eating mince pies and lebkuchen from Lidl. Also its better quality, at least when compared to iplayer that cant even give you the surround sound version of Dr Who that was broadcast on BBC 1 HD. And if I'm not there, I just record it.
Spotify: Cant stand the service. Its annoying and couldn't play me more than 2 songs from the same artist. I replaced it with a MP3 player which funnily enough doesn't charge me to use it and plays what I tell it too, when I tell it to and when I have no signal as I enjoy a walk along the beach. Funny, my MP3 player also has a FM radio built in and can record from it too and it works fin on the beach when spotify and DAB choke. Also funny, my smartphone has the same features, FM radio with recording which works when spotify chokes. However being on the beach the MP3 player gets the risky job of being accidentally dropped onto wet sand, not the smart phone
Audiobooks: I'm not going blind yet ;)
Oscillating wavelengths are a feature of the old analogue signals. That's what causes the interference. Digital wavelengths don't oscillate at all. They're rock solid and stick to a single frequency wavelength. (Or possibly two, and switch between them. I've just got to check that with Derek out back.)
My understanding is that the ability (not costs, just the licence etc) to run a 64Kb DAB station is circa £1m per year.
That means they're loaded down with adverts every 10-12 minutes. The only station I've known to try ad-free was Team Rock which died a financial death - I'm aware some religious stations don't run adverts but instead sponsor shows and have regular fundraisers though. Just as annoying.
Radio is dead. FM offered better quality and reach, and in trying to extend the choice from the narrow FM band they created DAB that is just endless low quality pop, religion and more pop. Very few specialist music stations apart from the decades-themed ad-laden Absolute group.
As mobile networks provide more and more data, and Android Auto / Carplay become more standard, it is just as easy to hit a podcast or a curated playlist as it is turn the radio on. I've had my car for 6 months and never tuned in any of the radio presets.
@Chiris
Mark Riley and Gideon Coe on R6.
Cerys on R2 and R6
Pick of the Pops on R2
Mayo and Kermode this afternoon on R5
Lots of comedy on R4X - the new series of Start/Stop is great
Odds and sods on R4
All listened to by me in the past week - some of the analogue ones on my Ferguson model 3189B which I've had since 1979.
If you like any music from the past 40 years I suggest you try Mark Riley or Gideon Coe.
As I understand it, radio listening in the UK is still going up. Which suggests that it ain't dead - even with podcasting listening also zooming up.
Although saying that, podcasting gets lots of media attention, but I only know about 4 people who listen to them. Whenever I recommend a good one to someone, I'm still sort of surprised by the fact that they say they don't bother.
Given that almost everyone has a phone that can handle a podcast app, so it's as easy as tapping your finger about 4 times - then they just magically turn up when you've got WiFi.
Here we go again.
Radio is outdated. Ok, where do you get your news from? Let me guess. You get it from twitter, several hours late.
Maybe you dont care about the news.
You do know that operating a smartphone in a car with an engine running is going to be illegal soon? I hope your playlist lasts long enough.
I really feel sorry if people end up lumbered with it.
No amount of BBC propaganda can change it's shitness.
Hopefully FM will zombify and never die, and future generations it's DAB that will be retired.
In the 60s a pocket radio would go all day on a 9V battery.
In the 2010s, a DAB radio will go nine minutes on a battery that needs it's own postcode.
How shit is that.
Imagine if they'd invented DAB *before* AM/FM ?
To be fair. DAB is not... it's companies use of it that is.
Either because it's expensive (I never said it was CHEAP and good).
But you can give the best F1 car in the world to the worst driver, and they will crash it and never get to the finish line.
That's kinda what happened with DAB... everyone involved crashed the tech into a wall.
The one thing is does have against it compared to FM is processing requirements, which adds the noted above "lag/latency", but also a LOT more power use for most cases on that processing (though I guess we are getting really efficient chips nowadays). Though nothing beats the old battery less/passive radio receivers!
In the 60s a pocket radio would go all day on a 9V battery.
In the 2010s, a DAB radio will go nine minutes on a battery that needs it's own postcode.
How shit is that.
Imagine if they'd invented DAB *before* AM/FM ?
Prior to transistors and tiny batteries, you needed a couple of huge, heavy, glass bodied lead acid accumulators to run your radio. And if you didn't have mains power, you had to cart them down to the Chemist shop to get the charged up.
The Edwardian style one and don't forget the top hat with the goggles, thanks/
"Prior to transistors and tiny batteries, you needed a couple of huge, heavy, glass bodied lead acid accumulators to run your radio."
I remember from my early teens that my parents used to sell in their electrical shop very big, low voltage dry cells for the filament circuit (B battery, 6 volts?) and a very small (about the size of a modern 9 volt) 90 and 45 volt dry cells for use in the portable radios of the day - mid to late 1960s I think, but starting to become less common then.
>sell in their electrical shop very big, low voltage dry cells...
Early valves ran with 2 volt filaments so they used a single cell accumulator to power them. The first valves were little more than light bulbs with electrodes in them, they were known as 'bright emitters' and used quite a lot of filament power so an accumulator was the logical choice for power. By the mid-1920s manufacturers had learned to coat their filaments with an oxide coating to promote emission, allowing the filaments to run with a lot less power. Once the valves became miniature (after WW2) the standard filament voltage for a battery radio was 1.5v supplied by a large dry cell. Irrespective of the filament voltage this low voltage supply is known as the "B' in the USA. The higher voltage anode (plate - US) supply is typically 45 or 90volts for a battery radio (a lot higher for mains kit -- I have an audio amplifier that runs 415v on the output stage). This supply is known as the 'A'.
(You may see in very old kit a need for a third battery, the 'C' battery; its typically 9v and provides a bias supply for the valves.)
OK -- a lot of non-computing information but its fun to know this stuff. I'm not that interested in modern radio like DAB because its not a very good solution to a problem that really doesn't exist. I swapped out my table radios years ago for Internet models and even these are now redundant thanks to voice assistants.
Sounds more like woo-woo to me. If I could remember the last time I listened to broadcast radio of any stripe in the car, I'm sure I'd care. Considering the number of Nissans on the road, the last thing I need is the interior of my car filled with the sound of inane fatuousness, mindless drivel and people with an overabundance of cheerfulness and nobody to inflict it upon.
thanks to the super-fast wavelength of around 220MHz
Apart from all the other idiocies, if you don't understand the difference between frequency and wavelength, you won't get far with the more technical stuff. I realise the press release was written my a marketing droid, but don't Halfords employ anyone with a GCSE in a STEM subject who could point out these flaws?
don't Halfords employ anyone with a GCSE in a STEM subject
Have you ever been to Halfords?
At a time when politicians of every hue are competing to spend more money on education, there does seem to be a fundamental question as to why the money we already spend seems to have so little effect. No-one, regardless of their GCSE subjects, should be so proudly ignorant.
I understand why the broadcasters want DAB. They control all the masts and can cram more channels in the spectrum. But what's in it for me?
I can use FM, which sounds better than DAB and which degrades gracefully, or I can use the Internet, with a hugh choice of channels (including small players who can't afford a slot on a DAB multiplex) and sound quality comparable to DAB.
What's the use case for DAB?
Errr. How about NOT being connected to the Internet. Perhaps you might like to try it for a while.
It is Broadcast which to me is far superior than streaming especially if all the people on the train/bus are listening to the same thing.
And you aren't tracked which for some of us counts for an awful lot.
And there is no subscription fees to pay (No TV license needed for Radio in the UK) which is an added bonus.
I think you have a point. The use case is going away on the assumption that everyone will have radio apps on a device and stream from them to your output device (speaker, in car stuff etc).
If you don't have a smartphone with a large data allowance you're not like the decision makers so things will no go your way. Decision makers all have large flagship phones with unlimited data paid for by their businesses and live in well expensive connected metropolitan areas.
I imagine their solution to your problem of poor reception etc is to get a large smartphone with unlimited data paid by your business and move to an expensive well connected metropolitan area. Because...why wouldn't you?
I recently spent a week in Kielder forest where I wasn't able to receive and digital signals. No phone, no TV and no DAB. The latter was unfortunate as I wasn't able to listen to the little DAB radio that I had in my caravan. So, I've just purchased an AM/FM radio in the hope that on the next trip I'll be able to listen to that. I don't see why it won't work as I had reception in my car.
Speed is actually a fair description. Sorry haters.
In the context of a radio network - speed is afforded by wavelength just as they describe.
Bandwidth is speed modulated by the real world.
Higher bandwidth afforded by greater speed enables better sound.
QED. Halfords were right.
I quite like DAB for the rock stations etc. I have an older car with a non-powered antenna and a small powered amplifier / splitter I got on eBay for about a tenner connects both the DAB and analogue ports on the header unit, providing a much better signal than the adhesive antenna that came with it. It works well all around the north east, and I've travelled up and down the country with reasonable success with it, although you don't half notice how crap the sound quality is even at its best when you pop a CD in!
I on the other hand regularly advertise that devices I am trying to market have defeated the gravitational constant. This makes them quite handy, because they float around your home/office, not taking up valuable floor and tabletop space, and they don't get underfoot.
Seriously, when I was in year 8 (approx 12 I think) I knew that radio waves traveled at the speed of light. Simply from school.
I also knew that wavelength IS NOT measured in MHz, which is a measurement of the frequency or number of cycles per second. Again, we did this at school, in fact I remember in year 10 looking at the way an antenna worked and how to calculate the length of the antenna depending on the wavelength desired. We also took turns to use a length of string to try and create an example of a standing wave.
We knew the difference between frequency, wavelength (and that older radios preferred to show it on their tuning dials). This was back in the 90's, when expensive FM tuners had RDS, there were 4 TV channels (5 if you were lucky lol) or many more if you pointed a dish to the sky, soda stream was 80's retro and the megadrive was the best (wanna sort that in the playground mate?).
Ok, I admit I may have paid more attention as I had a big interest in that sort of stuff since I was a kid. I quite liked my electronics set but in just over 20 years or so have we really dumbed down so much that nobody can even look up the basics of radio on wikipedia?
Hang on a sec.... I bet I can find something that exists elsewhere in the internet than just wikipedia. I'm using a thing called a search engine, its what we use to look things up on the web, just in case they are reading this and forgot that...
Here you go:
https://www.bbc.co.uk/bitesize/guides/z32f4qt/revision/1
https://electronics.howstuffworks.com/radio8.htm
Also:
> Digital transmissions contain more information than conventional FM / AM
No they dont, the audio is compressed thus it HAS LESS information in it, which is the WHOLE POINT as you can now fit more stations into the same bandwidth. Also dont try and say that you need the higher frequency in order to send digital audio, you dont. Look up Digital Radio Mondiale (DRM) https://en.wikipedia.org/wiki/Digital_Radio_Mondiale
> compared to the 75KHz or so wavelength of analogue FM / AM radio broadcasts.
What? Trust me if you are being upsold to a DAB radio from an AM / FM one you may know / have an idea through decades of the existence of these radios what frequency ranges tend to be used. Heck my 2015 Samsung smart phone has an FM radio built in and its shows the frequency with the RDS station name to the side. Also MY car radio isnt a DAB one, so I may know that my MW wave band does not go below 530KHz or so and the LW band does not bow below 153KHz so what kind of radio are they referring to when they say that AM / FM is around 75 KHz?
Next I bet someone will describe processor clock speed as the distance bits must travel to get to the USB port.
Ok, not everyone is going to remember this stuff from school if they were not that interested but failing to even look up this information and do some very basic research using tools that 5 years olds today see as the status quo is simply depressing.
I'm having trouble actually checking what the dispersion properties of radio waves in the atmosphere are. Visible light in solids tends to have lower group velocity at higher frequency (normal dispersion), which is the speed the signal reaches you at. However this can be the other way around depending on the medium and wavelength.
I'd guess this just another small canary in the coal mine suggesting that maybe there's something not quite right in the education system -- this crap should have been caught by any number of people before it got published. It wasn't so the reputation of the company takes a nose dive. (You're allowed to do the pseudo scientific thing if you're business is crystals, vibrations and quantum resonance -- or maybe just selling clean power for overpriced record players -- but not if you're in the actual business of selling technology.)
I thought that one of the issues with DAB is that it didn't work as well as the legacy technologies it was intended to replace**. Its also a redundant technology -- it so slow in gestation that the whole world of mobile data and the ability to steam whatever you wanted whenever you wanted it just swept past it.
(**AM radio might have crap sound quality but you can make a receiver out of 'common household objects', handy for post-apocalypse broadcast reception. FM has quite nice sound quality, you'll need actual electronics to receive it but its been around for ever and the technologies are not exotic -- and they don't require proprietary chipsets)(Both technologies can be decoded with computer programs if you want to go digital.)
"but not if you're in the actual business of selling technology"
Ah, that's your mistake. No large retailer is in the business of selling any material object. They are in the business of selling an idea. You, the victim, aspire to being X and their job is to convince you that what's in their box will deliver X-ness.
Obviously this is easier if you know very little about X and so a large retailer is probably someone who has picked up on this and focusses their attention on that "easy" fraction of the population. (Darwin, as applied to shopping.) It follows that the retailer no longer has to know much about X either and so they probably don't. If they know about anything at all, it is how to sell ideas and aspirations. X doesn't come into it.
Some years ago I was sitting in a room full of engineers listening to a marketing guy describing a novel and technically advanced product that we were about to launch. He claimed that "Some people say that it breaks the Laws of Physics." We were shocked, some of us went as far as to mutter into our beards.
A charitable explanation is that an engineer was paraphrasing Scottie, as a joke, when explaining the technical bits to him.
But I think we are all doomed.
DAB was in a VW car I borrowed whilst mine was being serviced recently. Bearing in mind that I hardly ever listen to the dross most radio stations put out these days, when I tried it, out of interest, it seemed to work well enough for car quality but also bear in mind that Bluebell Hill transmitter (puts out local TV as well - why they didn't use Wrotham is probably another story) is only just up the road from me, so nice strong signal. They all "burble" if the signal drops. Haven't got my early Technics DAB tuner up and running indoors after a house move, simply for the aforementioned dross reason and the fact that (I've probably mentioned this elsewhere - many times) when I first had it, there was no doubt it was superior. Noise floor so low, it was practically non-existent, decent dynamic range, etc; because, presumably, a half-decent bit-rate was used but, as time wore on, withe more and more stations shoe-horned in with ever-decreasing bit-rates, PLUS the dreaded Optimod processing seemingly being screwed up several notches, sound quality now is absolute rubbish. Might just as well be FM, for all the butchering that goes on before it actually hits the ether. (Younger readers please look it up!)
They say that their broadcasts contain "more information" due to using a "super-fast short wavelength". It is true that higher-frequency radio signals tend to also have a wider bandwidth, so there's nothing here about the speed of light. Compare FM radio to AM radio (or MW, Medium Wave, as I believe you call it).
The act of putting information on a carrier causes it to occupy spectrum, the amount needed being directly related to how much information you're adding. So the more information, the more bandwidth. Higher frequencies only allow more bandwidth - in conventional radios - because the frequency filter used to separate channels can only work with channel spacing that's percentage of the band frequency.......so "higher frequency, higher bandwidth" is really a "trick of the light" (!).
In modern (digital) radio you may find that the spectrum used by a 'channel' may be conceptually broken up into 64 sub-channels or more, with each channel carrying digitally coded data, anything from one to 64 bits or more. The bit stream that's making this up is usually coded to suppress errors, then its framed, the frames have coding........and it goes on.........
Fascinating, if a bit heavy, stuff. Makes you pine for the days where all you needed to listen to the wireless was an antenna, a tuning coil, cat's whisker and crystal plus a pair of high impedance headphones.
Depends what you mean by "Fast". I guess you could argue;
A) DAB has more bandwidth than FM, so it is capable of getting more information to the user...
B) The frequency is higher, meaning you get more waves per second, ie it's a faster way to get 1 million "waves"...........
But I think this was written by some marketing drone with no idea how it all actually works & probably imagines it's like broadband & speed is actually a major thing for the consumer when listening to what is, effectively, an unbuffered media stream with no reliability built in.
DAB is now pretty good in the parts of the UK I frequent. There are occasional black spots, but I can get to Scala Radio, Jazz FM, Planet Rock and so on just fine for most of the UK. Trouble is. I can get FM basically anywhere.
I love the way marketing departments re-write the laws of physics.
However, be a tad careful, on the coastline of northern France some do receive UK DAB. Some ex-Pats have installed specialist external antenna.
Many well known antenna companies offer hi-gain DAB roof antenna. Maybe Halfords are suggesting put roof antenna on cars ha ha ha
I spotted this way back in July ! Here's the original in all its glory.
Meanwhile, I'm still wondering who makes a DAB radio without 'set channels that are a bit like the channels on your TV'.
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All you have to do to embarrass the salesman is to put a DAB radio and an FM radio side by side receiving the same station. Then ask him why the DAB is lagging about 2 seconds behind the FM. Superfast eh, Hmmm? There's also LESS information in a DAB broadcast (as the situation currently stands) as a lot of the sound is thrown away before transmission in order to keep the bandwidth low. ALL the information picked up by the microphone is present in an FM signal (up to 15 kHz). AND they've managed to confuse the transmission frequency with the deviation. Halfords should stick to go-faster stripes and smelly Christmas trees.
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