213 replies to this topic

[alanh]

Deleted by the author

Edited by alanh, 25 March 2013 - 11:58 AM.

[:)]

read something in the press sayign we had recently adopted here the digital radio broadcastign method as in the UK ? any truth to this one. Does this mean that UK digital recievers will work here ? are there any officially published news on all this ?

[alanh]

alebonau,
I have not heard anymore as to whether they will change the compression method. If not, then people having DAB radios will be able to use them on the current test transmissions in Sydney and Melbourne. The start of 2009 will bring DAB radio to Brisbane, Gold Coast, Newcastle, Sydney, Melbourne, Geelong, Hobart, Adelaide & Perth.

alanH

[:)]

alanh, on Oct 30 2006, 10:24 PM, said:

alebonau,
I have not heard anymore as to whether they will change the compression method. If not, then people having DAB radios will be able to use them on the current test transmissions in Sydney and Melbourne. The start of 2009 will bring DAB radio to Brisbane, Gold Coast, Newcastle, Sydney, Melbourne, Geelong, Hobart, Adelaide & Perth.

alanH

thankyou alan, jsut wondering if the UK made DAB radios could be used here ?

[alanh]

All,
Digital Radio Australia "RADIO WELCOMES R & D GRANT" which is $2.2 Million go to the link for more.

Do not buy a DAB radio yet.

AlanH

[BlueDusk]

Any ideas how/if they're going to deal with out-of-market reception? With digital the signals wouldn't have the fuzziness, etc associated with long distance analogue reception. I'd imagine the Sydney commercial stations wouldn't be too happy if Central Coast, Wollongong, etc stations came up alongside Sydney ones in the list of radio stations.

[matt86]

Winston, on Dec 9 2006, 04:45 PM, said:

Any ideas how/if they're going to deal with out-of-market reception? With digital the signals wouldn't have the fuzziness, etc associated with long distance analogue reception. I'd imagine the Sydney commercial stations wouldn't be too happy if Central Coast, Wollongong, etc stations came up alongside Sydney ones in the list of radio stations.

There night not be "fuzz" but if the signal isn't strong enough there will be whole 'bits' missing? I'd imagine the result would be similar to what crappy mobile reception is like (ofcourse the audio quality would be much better)

[:)]

was thinking getting one of these guys, more as an am/fm tuner with dab being a bit of an extra

sony STSDB900S
http://www.sony.com....ategoryId=22848

manual from the uk site
http://pdf.crse.com/.../4255834121.pdf

nto sure how future proof it is and it mentions it cant do L-band whatever that is, any ideas Alan ?

[cyril]

L Band with respect to DAB is transmissions in the 1.4GHz band. The current trials are in BIII which is in the 200MHz region amoungst BIII TV transmissions.

L-Band DAB can be both satellite based and terresital in-fill transmitters.

I would expect that L-Band terrestial transmissions would not be widely deployed if at all in Aus due to coverage limitations at L-Band frequencies. All indications are that BandIII would be used for DAB.

Further it is expected that commercial deployment of DAB in Aus will include use of the AAC+ codec. If the receiver does not support that then dont buy.

My advice, wait till the DAB standards are firmed up.

Cyril

[alanh]

cyril
Here here.
There is no capacity on the current or the next Optus satellite for high powered 1.4 GHz transponders.

The ACMA has reserved lots of short wave bands for High Frequency DRM. It also uses the same compression systems proposed for DAB.

I have a sneaking suspicion that the commercial stations are not so interested in audio quality but want to be able to transmit video to radios in competition with broadcasting to phones.

AlanH

[:)]

interesting stuff guys. I was more lookign for an am/fm tuner with dAB being a bonus.

[karan]

does anyone know the situation with DRM? AAC format on computers has the ability to incorporate DRM, so it is possible to have issues like the "broadcast flag" not allowing recordings, which I imagine is especially applicable to the 'FM' broadcasts.

[alanh]

Karan,
There is a DRM trial transmitter in Windang near Wollongong. You may be able to receive it from your place?? The standard for DRM is to use AAC v2 which includes parametric stereo. There is also a push which will probably be successful to use it for DMB as well.

AlanH

[BlueDusk]

Sounds like Karan might be referring to Digital Rights Management as opposed to Digital Radio Mondiale.

[alanh]

Winston,
This sounds more plauseable, however it could be used to stop recording both DRM and pre-recorded sources!

Alanh

[RayDio]

Has anybody received the DRM Broadcast From Radio New Zealand International or any other shortwave broadcaster with a DRM signal ???

[cyril]

I suggest you check out Chris's site, he's done excellent work, Chris's DRM site

The RNZI antenna setup is optimised to cover the pacific but Aus is not well covered, PNG is however, so maybe if you are in northern Queensland you could get some coverage. Obviously we are talking HF Ionosphere propagation, so anything can happen.

Cyril

[alanh]

Cyrl,
I agree its a very good site.

AlanH

[GoForMoe]

Just wondering, what are the technical reasons why I can't use my DVB-T card to listen to DAB broadcasts? I understand why I can't do it for DRM, but not with DAB.

[cyril]

Quote

Just wondering, what are the technical reasons why I can't use my DVB-T card to listen to DAB broadcasts? I understand why I can't do it for DRM, but not with DAB.

You comment is jumbled, does your card support DRM or DAB?. I could understand it possibley supporting Band III DAB as it has a tuner in that band for DVB-T services, the rest is largly software, DRM however only exists below 30MHz, and I doubt the card would have a tuner response there.

Cyril

[GoForMoe]

cyril, on Jan 18 2007, 05:05 AM, said:

You comment is jumbled, does your card support DRM or DAB?. I could understand it possibley supporting Band III DAB as it has a tuner in that band for DVB-T services, the rest is largly software, DRM however only exists below 30MHz, and I doubt the card would have a tuner response there.

Cyril

My card supports neither (DNTV Live Pro), but I was wondering considering that DAB is in the same range as DVB-T broadcasts, why it can't be picked up with a regular DVB card?

[alanh]

chicki,
Digital Video Broadcasting -Terrestrial cards and STBs can decode extra audio channels included in the DVB-T signals and they are labelled radio , because there is no pictures transmiited.

Digital Multimedia Broadcasting will be using an extension of the standards used for Digital Audio Broadcasting as used in the UK, Canada and other countries. The Australians and increasingly other countries will be using AAC V2 compression instead of the Musicam used at present in DAB.

There are differences between DVB-T and DMB for example there can be 4 DMB channels in the space of one Digital TV channel for example. The sound compression is different and the control codes used to identify various functions are different.

If you want true digital radio you will have to wait for cards for the new standards. There is a manufacturer who is making the front end for digital radios which will recieve DRM up to 30 MHz, DMB in band 3 and 1.4 GHz band.

AlanH

[cyril]

Chiki, your original response was garbled, so portraid the impression that your card did decode BIII DAB, if that was the case then I have not seen such a dual mode card.

A DVB-T transmission whilst in the same band as BIII DAB has a much smaller bandwidth, 1.5MHz, the typical DVB-T chipsets used have been hardwired to bandwidths much greater 6-8MHz, further more the IFFT hardware part of the chips are setup to expect a certain number of carriers/datapoints, againt this is a fixed bit of hardware that could not be easily set for two quite different carrier arrangements.

That said, I guess that oneday someone will build such a device, as it makes sense, but as of today, in the interest of cost effectiveness the hardware front end (tuner/IF/ADC/IFFT) section of these devices is optimised for one or other application.

Cyril

[GoForMoe]

Most of those limitations sound like they can be overcome in software, is that possible at least theoretically? The 1.5MHz bandwidth is the only one of those that sounds like it would have some sort of impact that would stop it from being done.

[alanh]

chicki,
I agree although the IF filter will be 1.5 MHz wide instead of 7 MHz. This will make the receiver more sensitive and able to reject the DMB channels either side of the selected one.

There is also a software decoding issue.

The other issue is that the antenna must be vertical, where as all capital cities band 3 antennas are horizontal.

AlanH