Drm

[oceans777]

I am listening to the DRM signal from Sackville NB, Canada 9790 kHz - wow! Using a WiNRADiO G305 with M-Audio desktop speakers the sound is so good you wouldn't know it from FM.

So far I've only heard a few DRM stations and it is all or nothing but very impressive when it does come in.

Wondering who else is monitoring DRM and what results you've had?

[oceans777]

I knew this would be a fascinating, wildly popular thread...

[ka3jjz]

Of course, it would help if you told them what you were talking about!

DRM stands for Digital Radio Mondiale. It is a mode that is somewhat similar to IBOC in intent - it provides more fidelity to a HF signal, giving it an almost FM type sound. It's being touted as the way to bring SW to the masses - we all know that under normal conditions, a HF signal, even if it's very strong, is limited in that department.

As such, a DRM signal tuned on a regular receiver is nothing but noise. Therein lies the problem for folks that tune for weaker stations that are sometimes nearby - the sidebands tend to completely clobber them. In addition, with the exception of the Winradio series, there are no mass-produced radios currently in North America that can receive this mode. RadioIntel has had news in the past of portables set up for this, but they are generally coming out of China, or one of the Euro markets. There's no market for DRM here in the States yet, and without some education and heavy marketing, it's not gonna happen.

To receive a DRM signal, you need to tap the detector output (sound familiar? Yes, it's not unlike tapping a discriminator off a scanner to run programs like UniTrunker). There are software packages available to copy this - one called DReaM has been floating around for some time, another used by the WinRadio folks (I believe there is more than 1 version...).
Some WinRadio receivers are already set up for this, and can run their software without modifications. Anyway, not all radios seem to have the ability to feed a signal correctly, even with a detector tap.

For more detailed information and descriptions, see the bottom of:

http://www.radiointel.com/radioinfo.htm

Look at the center of the page for the DRM resources. And pray it doesn't come to a station near you.....

73s Mike

[oceans777]

I didn't realize there were no receivers with DRM other than going through all that.
It sounds good but I can see how badly it would affect other non-DRM signals. Lets hope it stays out of the US - looks like it will.

Next I plan to ask if anyone here has flown the space shuttle and how the stereo sounds...

[radio50]

I've been using a WinRadio 313e USB external software-defined receiver for a few months to listen to DRM. It has pretty amazing sound quality, but, as with many types of digital signals, if it starts to fade, it just goes away completely.

I have found the best signals into the Midwest USA to be from Sackville in Canada, in the evening. Attached is an example from a few minutes ago. I just have the little antenna included in the radio box, and really need something better. As you can see, the signals are not bad, but could be better. My biggest problem is electronic noise from inside my house.

The DRM signal appears to extend about +/- 5 kHz from the assigned frequency, so as other posters have mentioned, if there's something 5 kHz away, it's going to have one of its sidebands clobbered. A synchronous demodulator could receive a normal AM SW station on its other sideband, perhaps.

So, there are a few of us out here listening to DRM, to answer your original question.

[oceans777]

Very nice! I'd like to step up to the G313e - looks like a great receiver.