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G-CPTN
22nd Nov 2008, 19:08
A Sony SRF-S84N personal radio operating from a single AAA battery is my constant companion.
http://www.electronics-online.co.uk/acatalog/pr_no_lg_so_srfs84.gif
It receives FM and AM transmissions (though I listen almost exclusively to BBC Radio Five on AM medium wave).
In time the AM transmission is scheduled to be turned off in favour of digital broadcasts (which, I believe, are already established - albeit at reduced strength).
In addition, BBC Five Live Extra (that carries Sports reports, including excellent Formula One commentary) is purely digital (I have to listen via the internet on my laptop).
I've been considering the purchase of a DAB personal radio (I'm not interested in a fixed set, nor even a bulky 'portable') and PURE have at least one 'small' DAB portable though it's not cheap and has a fixed rechargeable battery with a 24 hour charge duration (meaning loss of use during mains charging). My current AAA batteries last several days of constant round-the-clock use.
In addition, the PURE website cautions that DAB reception might need a fixed external dipole aerial (and not just a 'portable external' aerial) 'if you have poor mobile 'phone signals').
A general rule of thumb, is that if you already have poor FM or mobile phone reception the chances are you'll have poor DAB reception as well and may need an external DAB aerial.
Yup! there is intermittent mobile reception as I live in a 'hollow' shielded from the (digital) transmitter (20 miles away) by buildings (and terrain - both local and intermediate). The AM transmitter is line-of-sight and two miles away.
So my query is:-
Has anyone got experience of DAB 'personal' radios - either PURE or any other brands? I'm talking about something no bigger than a box of Swan Vestas matches.

Flying Serpent
22nd Nov 2008, 20:28
I have the Cowon D2 dab

it's an iPod beater with DAB and a battery life of 50 hours...
Brilliant sound quality too.

google it..

timmyneedham
23rd Nov 2008, 08:16
I've got a Perstel DR201 which also has an MP3 player. Works fine everywhere but has aerial which you have to put up to use it, so you can't keep it in your pocket as you walk around for instance.
Other than that - it is fine - and makes R5L much better. You also get BBC World Service in quality.
TN

ampclamp
23rd Nov 2008, 09:00
Hello G-cptn, Australia will commence digital radio broadcasting in the new year with a new format DAB+.More info and services available (apparently).

So could you tell me if digital in the UK runs parallel to or as part of the normal analog AM and FM band services? AM here is roughly 500 khz to 1700 khz.FM 88 to 108 mhz.

Does the radio you use have a bog standard AM rx or have I mis-understood your post ?
AM analog, FM analog and FM digital?

Apart from clarity what else gives digital the edge?

I have not seen any DAB or DAB+ rx's in detail but the ones I've seen on the net appear to be FM only with some neat features.

apologies for thread drift but trying learn a bit before venturing into the stores.

seacue
23rd Nov 2008, 11:20
Innocent :8 question from the colonies:

Isn't DAB in the UK on UHF, higher in frequency than AM / FM ?

jammydonut
23rd Nov 2008, 11:40
I have the PURE pocket digital FM/DAB which has excellent DAB reception.
Antenna system is integrated with the headset cable also has a channel lock which prevents accidental switching when its in your pocket.

dazdaz
23rd Nov 2008, 13:51
At home (maybe it's my ears) I fail to notice any improved quality of reception with DAB over FM

green granite
23rd Nov 2008, 14:37
Isn't DAB in the UK on UHF, higher in frequency than AM / FM ?

Indeed around 220 -225 MHz.

If you don't want it portable then DAB's available on freeview

Keef
23rd Nov 2008, 15:50
UK DAB is indeed on 220 MHz (ish). I bought a DAB tuner, was appalled at the dreadful sound quality compared with FM, and gave it away.

They've tried to compress too much stuff into too little bandwidth, and ruined the ship. Something to do with Government revenue raising, I think.

I would be surprised if a pocket-portable DAB radio would work well in the UK, outside the fairly immediate area of the transmitting aerial.

FM will be a better on a pocket radio - but I notice the FM signal strength is dropping: I wonder if they're turning down the power as a prelude to telling us all we have to to to DAB whether we like it or not.

[Edited for typo in frequency!]

BEagle
23rd Nov 2008, 16:31
DAB is the biggest con around. Sound quality is worse than FM, coverage is patchy and the overall take-up has been much less than the greed of the government anticipated.

DAB+ would be a lot better, but can you see the government allowing another OnDigital-style farce by decommissioning the current DAB system, requiring everyone to switch to another standard?

For vehicle use, a European version of Sirius/XM would be the way ahead. But no doubt some copyright nonsense would prevent that....

Terrestrial digital TV is being introduced to free up huge swathes of prime UHF spectrum for the government to flog; they can damn well keep their greedy hands off the 20 MHz allocated to FM radio.

Saab Dastard
23rd Nov 2008, 17:35
DAB is the biggest con around. Sound quality is worse than FM, coverage is patchy and the overall take-up has been much less than the greed of the government anticipated.

Best summary I've ever heard.

SD

BEagle
23rd Nov 2008, 18:35
I've just checked the DAB rception guide for my postcode.

The only stations I can 'definitely' receive are Planet Rock, Classic FM, talk sport and Absolute radio. 3 other commercial stations have already seen the light and closed.

As for the BBC? Listed as 'fairly likely' to receive BBC1-4, plus 5 live, 6 music (for people 'passionate about pop and rock'......), BBC 7 ('comedy, drama and children's programmes'), 1Xtra ('new black music'), BBC Asian network and BBC World Service........

OK, I listen to Radio 2 and Radio 4 occasionally, but mainly to local commercial FM, such as the excellent Jack FM (JACK fm Oxfordshire : playing what we want (http://www.jackfm.co.uk) ).

Who did the audience research for the nonsense of DAB? Because it offers absolutely nothing which cannot be found on conventional VHF/FM. Classic FM needs a wide bandwith and Planet Rock needs a large dynamic range and good bass response. None of which is available on DAB - government greed has savaged the bit rate in an attempt to squeeze the few DAB channels into the minimum slice of RF spectrum. Big mistake - it sounds appalling.

I also note that 3 transmitters planning to broadcast DAB are no longer going to be commissioned. That seems like the writing on the wall to me....

DAB - Dismal Arrogant Bull$hit. It will never succeed - us oldies have our preferred analogue stations and digi-yoof prefers its iPod. So who really wants DAB - except for Greedy Gordon and the RF spectrum thieves.

seacue
23rd Nov 2008, 18:44
You might complain about audio quality of SiriusXM. Reportedly some music channels run only 24 kilobits per second. But that's the 40s channel and presumably in mono. The classical channels are assigned many more bits. XM uses AAC+, which is a good compression scheme for low bit rates. The Sirius compression scheme is said to be not as good.

That said, I have been an XM subscriber since only a couple of months after they started in 2001 and enjoy the 40s channel (which covers much 1930s music as well). My deteriorating hearing means that I don't notice the low bit rate.

Sirius and XM are at about 2300 MHz, and have numerous terrestrial repeaters to cover some bad spots.

US AM and FM broadcasters have "HD Radio", "in-band, on-channel" digital broadcasting. Actually it slops over to the channels adjacent to the station's main signal. This creates destructive interference which is so bad that very few AM station broadcast digital at night. FM HD isn't as destructive to "neighbors". The bit rate of HD for AM stations is less than 32 kbps. The rate for HD on FM stations is 96 kbps, but many subdivide into into a number of programme streams. The compression scheme isn't quite as good as AAC+. FM HD with all 96 kbps assigned to one programme stream isn't bad., probably better than analog FM when there is considerable multipath.

In any case, very VERY few HD AM/FM receivers have been sold.

Sony makes an HD AM/FM tuner which is said to be about the best analog FM radio ever be offered to mass market (and at $99). The HD feature can be disabled by snipping one wire. See the excellent review by K6STI.
Sony XDR-F1HD (http://www.ham-radio.com/k6sti/xdr-f1hd.htm)
It tunes in 100 kHz steps on FM, so might be useful outside the USA. Unfortunately it only tunes in 10 kHz steps on AM.

(Edited to improve format, detail.)

Say again s l o w l y
23rd Nov 2008, 19:58
Up here in the wilds of Scotland DAB is as much use as a punch in the face.

It's not as if we are in the boondocks either. In the South East it is fine, but elsewhere. It's awful.

We have a DAB radio in the kitchen, but it never gets used. I'm getting a WiFi radio instead. Much better.

Saab Dastard
23rd Nov 2008, 22:30
In the South East it is fine

No it isn't - at least in my experience!!

In SW London I can receive one multiplex well at a time, but no others. So I can choose the BBC and nothing else, but if I want a different multiplex I have to re-jig my aerial.

That is cr@p in comparison with FM - which just WORKS!

SD

Keef
23rd Nov 2008, 23:04
What you need, SD, is an omnidirectional DAB antenna on the roof, and a masthead preamplifier.

Antenna (http://www.radioworld.co.uk/~radio/catalog/omni-directional-antenna-p-2756.html)

I had more trouble finding a suitable DAB masthead preamp, but there has to be one - doesn't there?

Of course, that will only work with a fixed tuner, not with a portable.



I had to put up an outdoor FM Yagi antenna last summer, because the FM broadcast signal at our house had deteriorated so much. It's fine again now, but I suppose the next requirement will be a masthead preamp for that :(

ampclamp
24th Nov 2008, 01:18
Wow , glad I asked.Hardly expected such interest.
It seems all is not well in the world of DAB in the UK.
I've asked the authorities for some more info.

If anyone out there is interested they may wish to cast their bulldust detector over the digital radio Australia website.
Digital Radio Plus: HOME (http://www.digitalradioplus.com.au/index.cfm?page_id=1001)

Saab Dastard
24th Nov 2008, 07:47
What you need, SD, is an omnidirectional DAB antenna on the roof, and a masthead preamplifier.

Keef, I don't disagree with that, and ultimately for the fixed unit that (or something like) it will be done.

But I can have a DAB portable sitting alongside an FM portable, and the latter just works, while the former just doesn't (at least, only partially, and with much fiddling).

That's why I agree so much with BEAGLE's post!

SD

stickyb
24th Nov 2008, 08:28
And don't forget that it is no good listening to the good old greenwich time signal via DAB - it can be a few seconds out. Same problem as with freeview

BEagle
24th Nov 2008, 12:11
For home applications, either Internet radio or Sky digital offer all the radio one could possibly want.

Whereas in the car, the requirement is for nothing more 'geeky' than RDS radio. Remember when that was first launched with all sorts of options? No-one bothered with them and only station name and automatic tuning are really needed.

For traffic broadcasts, local radio tells you what's happening near to you and TMC on your GPS gives you the national picture. It's all very nice to hear the Radio 2 weather-wench yakking on about snow on the M74 when you're down in British West Oxfordshire, but it's rather an ineffective method.

Before GSM phones or RDS and TMC, I used to have a CB. Not so that I could go "One Nine for a copy", but to ask about the traffic. A 'westbound eighteen-wheeler on the M4'....OK, probably someone pretending to be one :suspect:, once gave me the heads up about a "Fender bender on the eastbound superslab", meaning an accident on the M4, so I took the next exit and went cross-country. So I met my ladylove at the airport on time! That's what I want car radio add-ons for, to provide useful information! Not to tell me about high winds in the Highlands 500 miles away, or ducks crossing the road in Little Piddle on the Gusset. Yet another facility which the useless DAB fails to provide.

Mind you, it was fascinating to hear the San Francisco traffic news on SiriusXM when I was in Ontario.......:hmm:

DAB will be yet another geekology failure, I predict. Like Rabbit phones, OnDigital, Betamax, 8-track tapes.

Whereas VHF/FM...............works just fine!

Another feature of DAB is digital dropouts. Instead of a bit of hiss and crackle in weak areas as the signal reduces, you g t irri at ng g ps in tr ns mi ons..... Which the human ear/brain finds far less acceptable than a slight increase in background noise. Digital is, by its very nature, far more artificial than analogue and needs a very robust signal with complex error correction, plus a good bit rate. Even if DAB had all that, just what conceivable 'killer application' benefit is it supposed to offer which VHF/FM doesn't?

http://i14.photobucket.com/albums/a341/nw969/Internet/zxzxz.jpg

Edited to push that DAB radio advert off the side!

frostbite
24th Nov 2008, 12:14
"I've asked the authorities for some more info."

There's trusting!

ampclamp
25th Nov 2008, 11:37
frosty, just want to get the facts right with frequencies etc .
I wont be asking if its going to be great cos I know the hot air will be blown up my nether regions.:eek:

Digital radio in Australia is barely off the ground with very few knowing anything about it.Asking stores about digital radio draws some blank looks or maybe quick trip to some dingey corner where they may have an old DAB set that wont work here soon anyway.

I want to update my stereo/entertainment electronics and all that goes with it so I want to learn all I can about what maybe coming and not buy something that may need updating sooner than expected.

Keef
25th Nov 2008, 11:46
If you're updating your sound system, are you concerned with sound quality, or will anything do?

If quality matters, get a good FM Stereo tuner as part of the new system. If quality doesn't matter, ...

If digital radio isn't up and running in Australia - wait! There are several standards being kicked around at the moment, and you don't want to be left with a Betamax digital radio in a VHS digital world.

The UK has been pushing digital for all it's worth for some years, although they seem to have stopped now. The sound quality and the signal quality are dire, and I wouldn't be surprised if the whole thing is allowed to die quietly. I'll even conduct its funeral for no fee (pro bono).

timmyneedham
26th Nov 2008, 14:14
Keef - I don't recognise your experience with DAB at all. Where I live, we can't get any FM stereo signal in the house (and no TV signal either) but DAB radios work really well, by which I mean radios made by Pure and Sony. I get excellent reception on all the BBC stations and it means I can listen to BBC WS and R5L without all the MW/LW interference I used to get.
All right? Not arf!
TN

Dick Fisher
26th Nov 2008, 18:39
I have radios of almost every description at present - DAB/AM-FM/Internet - and I am an avide radio listener.

However, I still want to invest in one of those new-fangled internet radio thingies for our house in France. It must also play my music files wirelessly from my laptop, it must be stereo and it must be both good looking and provide "good" sound quality.

I've done the ususal research, and am not completely satisfied with what I've found so far. Any PPRUNER already made this journey? If so, what would you recommend?

Say again s l o w l y
26th Nov 2008, 18:49
This got the best of award from the gadget show.

You can get it from Argos for £99.

Ministry of Sound Direct (http://www.digitalstores.co.uk/ministryofsound/productdetail.jsp?productPK=unittest-ThU8QvPFsOih9v2jqN3IEb-1)