Reported in the Spring 2007 issue of a DRM newsletter, since its beginning in Paris in 1996, other broadcasters have joined the consortium and today as many as 90 members, from 30 countries worldwide, have formed the DRM alliance. China was an early participant and leading broadcasters now include Radio Luxembourg, Radio France International, Radio Netherlands, Radio Canada, Voice of Russia, Vatican Radio, and Radio Sweden. Radio Luxembourg has returned to the air using digital DRM on 208 metres medium wave backed by the world’s third largest media group, Bertelsmann. In addition, Radio Luxembourg is also beaming short wave digital towards the UK and Ireland.
Also reported in the Spring 2007 newsletter, the USA has now joined the consortium with the National Association of Shortwave Broadcasters participating. DRM is now used worldwide by 32 broadcasters and more than 40 hours of English language programmes are broadcast across Europe.
Reported on 6 July, a full-bandwidth 18 kHz DRM medium-wave trial in Delhi, India, took place as part of a DRM simulcast technology showcase sponsored by public-service broadcaster All India Radio (AIR), the Asia-Pacific Broadcasting Union (ABU) and the DRM consortium. According to Mr. Sharad Sadhu, head of transmission technology and spectrum at the ABU, this is quite a significant event. Radio broadcasters in the Asia-Pacific uniquely use 18 kHz-wide channels in the medium wave, and using DRM in the full channel will enable them to provide a very high quality stereo service to listeners. The trials demonstrated DRM digital radio transmissions in the medium wave band using Single Channel Simulcast (SCS) and Multi-Channel Simulcast (MCS) technologies. It also demonstrated local DRM radio transmissions in the 26 MHz band, Near Vertical Incidence transmissions and DRM shortwave radio transmissions. For the trials, Thomson provided a DRM-ready 100 kW TMW 2100D medium-wave transmitter and a digital front-end including the Thomson Stratus DRM modulator and the Cirrus DRM multiplexer.
Mass production of receivers using the new DRM standard has commenced. As well as DRM on short, medium and long waves, these receivers cover existing AM and FM bands. With DRM, the problem of fading, interference from appliances and other stations, has been solved. DRM short wave is received with ease and a total absence of noise. Difficulties in receiver tuning have now been eliminated. It is only necessary to enter the name of the station and the receiver locks on to the signal without any fuss or further effort. The result is very stable reception of a quality similar to that of FM. Affordable car and portable ‘smart’ receivers were released last year. Bosch, Panasonic, Roberts, Sangean, Morphy Richards and Visteon were among eight leading brands showcased last Autumn at the Berlin and Amsterdam consumer shows.
(Source: ABU Digital Radio/Aug 07)