Thursday, November 14, 2024

DRM in China update















Above: Image of emergency broadcast test 17700kHz coverage simulation

Lots of DRM activity going on in China!

It was reported via a Japanese listener on WOR that on 29 October 2024 an emergency broadcast test occurred on 17700 kHz in DRM mode, broadcasting weather in Sichuan Province.

<https://mp.weixin.qq.com/s/VIoFE3zpt1H8ncTAlCY86A>


B24 DRM schedule of CNR release 8 November 2024:

Beijing      13825 kHz 0100-0900 30kW 175deg.

Dongfang  17770 kHz 0100-0900 30kW 16deg  ID:27FA

Kunming   15180 kHz 0100-0400  0800-1100 30kW 32deg  ID:3EB

                17800 kHz 0400-0800 30kW 32deg  ID:3EB

Urumuqi    9655 kHz 2200-0100  0800-1200 30kW 98deg  ID:3FC

                17830 kHz 0100-0800 30kW 98deg  ID:3FC


Additional frequencies registered in HFCC B24 but not officially announced 

Beijing       6030 kHz

Dongfang   11695 kHz (and possibly 21530 kHz)    

Qiqhar       11990 kHz 

                13710 kHz 

                13850 kHz 

It is thought that the Qiqhar transmitter has been converted to jamming. Also 21530 kHz (30kW 341deg Dongfang), which was registered as an irregular frequency in A24, is reported to have been still used in B24.

<https://cahcn.github.io/drm/>


Another set of frequencies using the CUC-ECDAV ID (corresponding to the Research Center for Radio-Television Digitization Engineering of the University of Communications of China) have been spotted on:

6185 kHz

7500 kHz

9500 kHz

11500 kHz

Lastly, on 2 November 2024 the ID DRM broadcast from Fuzhou was seen. 

<https://kbysradio.wordpress.com/2024/11/03/%e4%b8%80%e5%91%a8%e7%ae%80%e6%8a%a5%ef%bc%882024-10-27-11-2%ef%bc%89/>


With all these frequencies and activity, we can hope that the great propagation conditions result in North American decoding for many of these signals!



Friday, November 1, 2024

WMLK in DRM on 9275 kHz

WMLK has been reported testing DRM on 9275 kHz around 23:00 UTC. They were seen using Mode B 10kHz, xHE-AAC  Stereo 17.46kbps.

Text of "WMLK Radio DRM transmission with Ampegon TSW2300 transmitter - stay tuned @ 9275kHz".
That equipment is capable of 150 kW mean power with 9 dB crest factor. HFCC shows they are targeting Europe on that frequency at that time. 

It is thought the DRM ID intro to their analogue broadcast occurs when they boot the Ampegon software to start the transmitter.  It may not actually be by choice! Look for it on 9275 kHz at 2258 to 2300.

Wednesday, October 9, 2024

BritAsia pop-up broadcast for India




Several DRM aficionados in China are receiving a BritAsia broadcast on 21575 kHz. It is being identified as "BritAsia pop up DRM service for India". Reports suggest a strong signal in China of SNR 25dB at 14:20UTC on 9 Oct 2024. From the DRM ID E1C123, this is likely originating from Woofferton.

Friday, September 20, 2024

Wednesday, July 17, 2024

National coverage using DRM



Interesting discussion of Nationwide broadcasting using DRM. Many European countries could easily shift to DRM for their broadcasting needs now that the CML DRM1000 chip is available for receivers. In North America, national broadcasting services such as NPR could shift to DRM for signal delivery - if only DRM was permitted on AM/MW and FM.