Who remembers the heady days of LM Radio, Capital Radio 604 and even Springbok
Radio broadcasting loud (but perhaps not so clearly) on medium wave in South Africa?
With the advent of FM radio, medium and shortwave local broadcasts became a thing
of the past as they lacked the quality and stereo capabilities of FM. However, the very
fact that so many stations require space on this overcrowded frequency has prompted
various other transmission methods in an effort to make use of both medium and
short wave frequencies, while maintaining the high quality of FM technology.
One example is the digital radio standard developed by Digital Radio Mondiale™
(DRM), an international not-for-profit consortium, composed of broadcasters, network
providers, transmitter and receiver manufacturers, universities, broadcasting unions
and research institutes. The aim of the DRM Consortium is to support and spread a
digital broadcasting system suitable for use in all the frequency bands up to and
including VHF Band III.
“DRM is the universal, openly standardised digital broadcasting system designed for
all broadcasting frequencies, thus covering very large geographical areas and reaching
listeners in remote areas of a country,’ says Radu Peter Obreja, marketing director of
DRM.
Obreja believes that the DRM standard is the only global, all bands, open, efficient
and green digital audio broadcasting solution. He continues: “DRM has two major
configurations – DRM30 is intended for broadcasts on short, medium and long wave
up to 30 MHz and provides very large coverage and low power consumption. The
configuration for the VHF bands above 30 MHz is called DRM+, tailored for local and
regional coverage with broadcaster-controlled transmissions. These configurations are
two digital broadcast modes on a single standard.
“The DRM configurations share the same audio coding, data and multimedia services,
service linking, and signalling schemes. DRM provides high, FM quality sound,
combined with a wealth of enhanced features such as Surround Sound, Journaline text
information, Slideshow and EPG.’
A key feature of the DRM standard is the Emergency Warning and Alert System, which
is vital for governments of large countries, where such messages need to be sent
instantly to remote areas without television or mobile phones.
DRM is very cost effective for broadcasters to run, as they don’t have to resort to
multiplexes, which are expensive to use and maintain. DRM, by using all radio bands,
has a very wide reach in big countries, where the traditional FM signal does not reach.
For an FM signal to reach all corners of a large country, broadcasters / governments
need to go to huge expenses to install hundreds of expensive transmitters to cover
those areas in FM. With DRM, this is not the case. By using the AM bands, the DRM
standard reaches all remote areas.
“By having DRM digital broadcasts, there is no longer the need for both broadcasters
and listeners to refer to AM or FM,’ explains Obreja, “as the radio stations are
accessed by their own station names and not by their frequency.’
Capital Radio 604, popular in the 1980s for its broadcasts from the Transkei into
KwaZulu-Natal, may well be back on medium wave and intends offering an AM
service. It could also launch digital broadcasts using DRM and take advantage of the
internet as a listening platform.
The station’s investors include ex-governor of the Reserve Bank, Tito Mboweni,
veteran broadcaster Kevin Savage and technical guru Mark Williams.
It is believed that there are seven South African applicants for broadcast licences on
medium wave pending, all of who are interested in using DRM.
