Does DRM have a future?

[mitajohn]

Hi all,

Some info from the Russian Radio Symposium found here: http://radiomagonline.com/digital_ra...mposium-11187/

[KD7YUF]

From what I am seeing the answer is no, DRM does not have a future. Not unless stand alone receivers come to the market at an affordable price worldwide do I see this technology taking off. Attempting to receive the broadcasts that are out there has become a frustrating experience for me personally as I can't find anything state side which would allow me to listen to them. This is quite a technology with huge potential but under the current circumstances its being suppressed and fairly obscure with reception limited to those who are able to mod their receivers or those who own SDRs. This is the only hurdle I see that DRM must get over in order to really take off but its all down to persuading the receiver manufacturers who have a world wide presence such as Icom, Yaesu, and Sangean to build and sell DRM receivers on the world market at an affordable price. As soon as this happens more broadcasters will adopt it and the number of hours of DRM programing each week will increase. Over all, it just depends on receivers coming to the world market in order for DRM to become better known and more widely used. Its a great technology, lets not let it die off.

[Roy Sandgren]

KD7YUF, Dear friend, in a combination of AM,FM,DAB+ and DRM in one compact reciever it has a future. To replace all am transmitters around the world to drm, it will take 20-30 years.DRM+ will replace the FM-band, within the next 10-20 years.USA did HD-radio instead.

[KD7YUF]

Right, but HD Radio is just for AM and FM here and the FCC did approve DRM for use in the shortwave broadcast bands and its being used right now by the Voice Of America from the Greenville North Carolina site and also WYFR in Okeechobee Florida is in the process of converting one of their transmitters to use it. Its supposed to have a worldwide appeal and that is what I was referring to not just the European market where a combination of DRM along with analog AM and FM and digital DAB, DAB+, and DRM+ would make quite a bit of sense. This is also based on my personal frustrations as I want a DRM receiver but can't find one and also can't find downmixers which go from either 9 MHz to 12 KHz or 455 KHz to 12 KHz available in the US which are affordable to listeners and I say 9 MHz as that is an option with Icom receivers.

[Roy Sandgren]

KD7YUF, I got a drm reciever in my car and the engine went totaly broken this afternoon, just 500m from my friends place. He repairs friends cars and vans.he got a trucking company.Ok, new engine or a newer car, thats the question??. When i recieve drm in my car, like RTL on 49-m, it's just like an FM-station, but I'm a little outside the target area, so droputs can happend.
When some broadcasters have the target area, were I do live, it's very great to pic up in a car.
Final conclusion, drm is not dead, if goverments issue drm licences and manufactors make recievers with drm as standard.
Slowly but surely...

[KD7YUF]

The way I see it, its the other way around and was that way with HD Radio. It did not really take off until sub $300 receivers started to show up on the market resulting in more and more stations adopting the technology. DRM is just frustrating for me especially since I posted a request for help with a down mixer which was designed by a forum member that I can't seem to get to work at all despite everything being wired up correctly and the SA602 IC that its based around getting 4.5 volts DC as it was intended to. And also using the correct components in all but one situation as I was unable to find a .002 pF capacitor and replaced it with a trimmer capacitor taken out of an old and dead CB radio.

[Roy Sandgren]

Hi again, if the FM/AM/DAB+ recievers get DRM as standard, it will be a help to the market of DRM. Hope soon the UNIWAVE,HIMALAYA,TECHNISAT get the DAB+ as standard and other models in combination of DAB+ and DRM.
Here in Sweden we are still awaiting the proposal of digital radio in band lll, tv channel 12 and DRM. Then we have to watch if any broadcasters want to go DRM?? perhaps in the 26 MHz to local service. 2 x 20 kHz, better than even DAB+. Let us use the radiowaves in the name of freedom!!

[KD7YUF]

I have heard about those 26 MHz transmissions in Europe and even ran across one while I was still able to access a DRM receiver in southern Sweden. It was the Radio Luxembourg one from Junglnster on something like 26.045 MHz and it decoded quite reliably through E-skip. I want a DRM receiver very badly but can't find one in the US so my only option is to mod an existing receiver to down mix its IF to 12 KHz for sound card decoding which so far has been a failed effort or to import one from Europe and mod it to work with 115 volts AC so that I can use it here in the US to receive the DRM shortwave broadcasts which are so far elusive to me.

[Roy Sandgren]

Hi KD, must be someone in the states able to help you out of this problem.
I didn't know that RTL was on 26 MHz, but I can get them on 6095 kHz, even outside the target area, wich is Sweden.50 kw DRM + antenna beam.
For the USA I suppose you need some longwires or active vertical antennas to get DRM service. You will always find some solutions around you with a little help from radioamateurs, they know better..

[KD7YUF]

That was the easiest one to get on that receiver too, now that I think about it the thing could very well have been in Malmo and the receiver was of course an SDR one made by Ilad in Italy. The transmission I think is on 25.995 MHz (check the DRM broadcast schedule to be sure) and very low power but with a good E-skip opening to Luxembourg it should be receivable on a good antenna even an omni would work fine. As for my situation, there is one other idea but unfortunately its in a back issue of QST magazine and I am no longer an ARRL member. In the October 2003 issue there was a project consisting of a DRM down mixer which goes from 9 MHz to 12 KHz based around the Philips SA602 mixer/up/down converter IC which I happen to have available to me right now and used a parallel L/C circuit for tuning rather than a crystal. I have been trying to find the complete schematic and article for it but can't access it anywhere online because of having lapsed membership.

[KD7YUF]

I found the schematic but just need to convert the values from nanofarads to microfarads since it would be easier to buy parts in the later of the two.

[Roy Sandgren]

OK KY, you did visit Malmo. Yap, some drm in Luxemburg was on air, even some in London on 26 MHz. Now we need some experts to you helping you out. I'm awating the proposal of digital radio in Sweden wich includes DAB+ and DRM.
See you,
Roy, Malmö Sweden

[KD7YUF]

No I did not actually, it was a receiver on the former DX Tuners service which was in the area and was as I said an Ilad SDR receiver with a DRM demodulator in its software. This is actually what did it for me as well, I was so impressed with the sound quality even over the stream that I absolutely HAD to have a receiver which could do DRM. Here in the US even 25 and 26 MHz DRM service might be possible given that the 11 meter shortwave band is all but deserted but it all depends on what I mentioned before. Up there its mostly auxiliary transmitters for AM stations which actually use narrow band FM oddly enough whose purpose is for remote broadcasts. Those make some fun targets for DXers during the summer E-skip season and also during solar maximums as they have been reported as far away as Europe and Asia despite their relatively low power. The situation for that here in the US is that the FCC approved DRM for use on the shortwave broadcast bands and Ibiquity's HD Radio on the AM (MW) and FM broadcast bands instead of DAB because we are quite literally out of spectrum.

[CT4RK]

Hi KD7YUF.

All you need is this receiver.

http://www.elektor.com.pt/products/k...1).91475.lynkx

Of course you need know some basics of radio hombrew, and know read the electronics components values, for assemble a radio like this.

[mvs sarma]

Originally Posted by CT4RK

Hi KD7YUF.

All you need is this receiver.

http://www.elektor.com.pt/products/k...1).91475.lynkx

Of course you need know some basics of radio hombrew, and know read the electronics components values, for assemble a radio like this.

Except soldering SMDs , there should be no problems, provided he has a spare board.
I got them locally made Double sided PTH.
But the issue here , is that it can cater for AM(HF band ) only not DRM/DAB in FM mode, I fear. Of course, a fully assembled board is being sold by Elektor and KD7YUF could very well order for it.