Wednesday, March 02, 2022

ABC Digital Radio Mondiale transmission on medium wave

The Bendigo Amateur Radio Club held a meeting where Brad Geier, VK3VLK, spoke about the great future of Digital Radio Mondiale (DRM) transmission. I didn't realise that the ABC has been running a transmitter on 747kHz from Wangaratta.

I can see the transmission quite clearly here at Drummond and also on the PkLoops SDR at Croydon.

In the past I've been able to receive DRM transmissions from Radio New Zealand International and they can sound very similar to FM quality despite weak signals and band noise.

The software needed to decode DRM is Dream. I couldn't get the latest version, 2.2 working but version 2.1.1 does work under windows. Another interesting lead is swradio-8 which I was able to build but not quite get going on Linux.

I'm using the IC-7300 as receiver by switching USB audio output to IF, choosing AM and winding the bandwidth out as much as possible.

My antenna is not very well suited to 747kHz so I'm not decoding audio just yet:


VK3BAL said...

If it is of any use to you a runnable version of DReaM2.2 can be found at the following web site.

I have yet to get a signal that has resolved audio out. I have got the FAC and SDC CRC's green but not the MSC CRC. Guess I need a stronger signal.

The Hound

Peter Marks said...

Thanks Mr Hound,

I'll try the 2.2 download you linked.
I haven't been able to decode audio but I can decode metadata. The signal isn't quite strong enough here either.