So, one night, I couldn’t sleep so I stayed up scanning the airwaves with my Winradio Excalibur G31DDC and my Wellbrook Communications ALA-1530 loop antenna. I stumbled across a strong DRM radio transmission (i.e. digital shortwave).
Digital Radio Mondiale (DRM) is a digital radio mode really only used in shortwave and AM broadcasting. It offers a variety of bandwidths, protection levels, and codec modes and can convey textual and data information as well. Mostly used is a 10khz bandwidth, with a single Audio service.
At 1553UTC (2:53am local time), I managed to stumble into the 12115khz The Disco Palace service from the USA. I was really excited. I had tuned to 12109.5khz with USB reception mode, demodulation bandwidth about 11.5khz and fast AGC to “capture” the whole signal into AF. This was routed through Virtual Audio Cable to Dream (a free DRM decoder, as I wasn’t going to buy the Winradio DRM license if I didn’t have to) – and out comes the audio! Of course, going this way, you suffer from resampling issues and sync issues and degradation in SNR – the Winradio DRM license would offer much more robust decoding.
Their transmission was in Mode B, 10Khz, with 20.96kbit/s EEP AAC+ P-Stereo encoding. ID was A06021 USA Genre: English Pop Music. I even made a capture of it – by capturing the DRM signal on one channel, and mixing the recorded WAV file from Dream (approximately synchronized) on the other. The analysis windows are shown in the video – so you get the full DRM experience:
Due to the copyright issues with copyrighted audio, this video is presently not available in Germany, and may not be available in the future if it is taken down. Ultimately, I see no good reason given the relatively low quality of the audio, the fact I’ve made it monaural in one channel, and the fact that some of the songs are partial.