At the Winter SWL Fest, DRM digital shortwave worked, except when it didn't.

[MikeB]

http://www.kimandrewelliott.com/?id=1211

[zfyoung]

I think when DRM does'nt work, it is not a problem with this system.Rather it is a problem with the engineer on the transmission site:Why are they so "greedy" to jam-pack so much information into the bit stream when propagation conditions are bad. Even when they lower the bit rate, why don't they choose the their source coding strategies wisely e.g. like CELP,HVXC in combination with SBR. No wonder they got "telephone grade audio" or audio drop-out.

AM had over 80 years of time to develop and perfect itself, and we can safely say it had reached its full potential. DRM is a new player, and many novel techniques had not been deployed in real life broadcasts to improve service quality. For most of negative results about this system, it is primarily due to service mismanagement.

[HC7AW]

Actually, we only used 9.8 kbps during the middle of the day when HCJB cannot even deliver a listenable analog signal to north America. We then moved up to 11 kbps in the late afternoon and then 17 kbps in the evening with parameteric stereo. Our propagation studies said that we should not have gotten anything there at all with only 4 KW of DRM power.

So I am rather proud of our effort :-)

Doug