"Dream" (version 1.6.1cvs) screen shot while receiving an actual signal in these tests with a AOR AR7030.
(N9EWO photo)

Just as the title states, this allows a person that owns an AOR AR7030 or JRC NRD-545 and a fast Microsoft Windows based computer to have a “taste” of DRM (Digital Radio Mondiale) without doing much in the process. Keep in mind that this will not give for a very smooth 100% error free signal doing it this way. Expect some (if not many) dropouts.

Normally to do DRM reception for a particular model host receiver it has to have or be modified with a wider bandwidth filtering (12 Khz +), plus adding a 12 kHz IF down converter circuit board, which is then connected to the computers sound card audio “line” input where the DRM decoding software is installed. In my case here I'm using the free "Dream" software.

With this “down and dirty” method, no modifications are done to the AOR AR7030 or JRC NRD-545 receivers in any way.

 As the case is with DRM signals, the received signal MUST be super strong and with absolutely no interference, otherwise you will hear nothing.

The computer that has the Dream software installed better be fairly speedy, I would say at least at 1.5 Ghz or faster (this is a guess), Intel Pentium 4. In my case it was a Windows XP home OS with 512 MB of memory.

I used the Dream version 1.6.1cvs for these tests. The files are just unzipped into a directory that you make on the hard drive. No install of the program is done. You just add the "qt-mt230nc.dll" if needed (downloaded separately) into that same directory that you just unzipped. That's it, run the program from that directory.

Adjustments in the Dream program I made:
(Important : Not saying I have all of the answers here, so experiment, but here is a start)

(Top bar selection) View  > Evaluation Dialog

Channel Estimation: Frequency Interpolation: Set to Linear (Wiener can work too with the AR7030)
Channel Estimation: Time Interpolation: Set to Linear (Wiener can work too with the AR7030)
Misc. Settings: MLC: Number of Interations: Set to 1 (the higher you set this the more CPU horsepower is used)
Interferer Rejection: Bandpass Filter ON
(I switched off the Reverberation)

(Top bar selection) Settings > Sound card Selection
Be sure your “Sound In” and “Sound Out” are set correct for your computer.

Settings on the AOR AR7030 that I made:

Example: 9800 kHz DRM Sackville RCI 2130 UTC

Off tune the receiver 5 kHz down: So in this case, 9795 kHz
Mode: USB
PBS Control: + 1.5 kHz
AGC: Fast
Bandwidth: 9.5 kHz
Audio Level(s) (set in config menu): We started at 77 %

Radio / Computer Connections and Adjustments

The receivers “Audio Line” output is connected to the "line in" on the computer sound card.

The "Record" sound card adjustments (panel) should be made using the "Line In". If the sound card has a "wave out mix" selection and adjustment on the “Record" mixer panel, be sure that is not used (selected off) and use the  "Line in" in the Record panel only.

Yes, it is very picky where the adjustment is set. Again ANY interference of course usually kills the signal totally.Make sure the audio level is kept constant. No red bars in the Dream’s audio level meter (or only very slightly). The idea is to have those 3 little cubes (lights) right under this level meter to be all green (version 1.6.1cvs).

As far as the "Playback" sound card adjustments (panel) went in MY case (this may not be the same with your situation) , I have the "Line In" and "Microphone" sliders muted (checked). But was sure NOT to have the "Volume Control" and "Wave" muted, and these levels are turned up fully. The rest really did not matter in my case.

I tried and used the JRC NRD-545 as well but here in my tests (as below) and it was even choppier, but for those who want to try it anyway here are the settings I used (below).

JRC NRD-545 Settings I made (use same Dream program settings above):

(Be sure the Filter Slope # 32 User Set Up as: LOOSE)

Example: 9800 kHz DRM Sackville RCI 2130 UTC

Off tune the receiver 5 kHz down: So in this case, 9795 kHz
Mode: USB
PBS Control: + 2.30 kHz (fully clockwise)
AGC: Fast
Bandwidth: 9.99 kHz
Tone Control: Fully Clockwise

Anyone who gives this a try is totally on your own and I will be unable to give any technical support. I cannot tell you if this will work with other receivers that can provide a W-I-D-E bandwidth in SSB modes (with at least 9 kHz bandwidth filter) and with Pass Band Shift ?? AlI I can say is to give it a try uning the above information as a base ?

Reminders again that this may not work the best so treat this as an experiment and you should have fun with it. I do not have all of the answers here.

Have fun and good luck.

Dave N9EWO

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