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http://www.guardian.co.uk/media/2011/oct/09/bbc-radio4-long-wave-goodbye
Radio 4's long wave goodbye
Last pair of valve transmitters signal end of 198kHz, home of BBC's Test
Match Special and Today in Parliament
Long wave transmission's days are numbered.
A handful of specially crafted glass valves each measuring one metre high
are all that is stopping the historic home of Test Match Special, Yesterday
in Parliament and the Daily Service going suddenly and permanently off air.
BBC Radio 4 long wave, which transmits on the 198 kilohertz frequency,
relies on ageing transmitter equipment that uses a pair of the valves - no
longer manufactured - to function.
The valves, at Droitwitch in Worcestershire, are so rare that engineers say
there are fewer than 10 in the world, and the BBC has been forced to buy up
the entire global supply. Each lasts anywhere between one and 10 years, and
when one of the last two blows the service will go quiet.
Last week, Mark Thompson, the director-general of the BBC, signalled the
beginning of the end for the 198 long-wave service, which is still used by
90,000 homes in Britain to receive Radio 4 in areas where short-range FM
does not penetrate.
Aware of the public sensitivity - the service fought off a closure threat in
the early 1990s - Thompson promised that Radio 4 long wave would "find a new
home" on both analogue FM and digital radio once suitable frequencies could
be found.
Denis Nowlan, the network manager for Radio 4, said: "This is technology
that is becoming obsolete. Digital radio now reaches 97% of the population,
and there is plenty time to find new homes for long wave-only programmes."
Radio 4 was traditionally broadcast on long wave, using frequencies used by
the BBC since the 1930s, but the station has long been aired on FM and
digital radio and online. More recently, the long-wave service has been used
to carry a handful of traditional programmes deemed unsuitable for FM, while
the range of the long-wave signal also ensured that ships could pick up
shipping forecasts.
The best-known programme broadcast on long wave is Test Match Special, which
would otherwise dominate vast chunks of the Radio 4 schedule. Yesterday in
Parliament airs when Westminster is sitting at 8.30am, cutting out the last
30 minutes of Today on FM, while Radio 4's Christian worship programme, the
Daily Service, is carried every weekday at 9.45am.
So antique is the transmission equipment that the BBC does not believe it is
possible to manufacture new valves because slightly faulty replacements
could cause a catastrophic failure of the other parts of the transmitter.
Whenever the valves fail a dangerous "arc of power" surges through the 700ft
Droitwitch transmission masts.
Building a new long-wave transmitter for Radio 4 would cost "many millions
of pounds", according to BBC insiders. Part of the problem is that pumping
the signal so that it can cover England, Wales and lowland Scotland requires
500 kilowatts of power, far more than other long wave transmitters, which
makes the kit both unique and expensive. Meanwhile, modern mariners use
other technology and services to get forecast information.
Highland Scotland is covered by two smaller transmitters and Northern
Ireland does not easily receive Radio 4 long wave. However, the signal is
strong enough to be audible in parts of the Netherlands, Ireland, France and
Germany.
The BBC began national transmission with the National Programme, the
predecessor of Radio 4, in 1926. Transmission moved to 200 kilohertz in
1934, when the BBC moved its transmission to Droitwitch, and has remained at
that frequency, allowing for a slight shift to 198Khz ever since.
Built under the leadership of Sir John Reith, his last act as
director-general after being forced out in 1938 was to personally close down
the National Programme at Drotwitch before signing the visitors' book and
leaving.
Radio 4's long wave goodbye
Last pair of valve transmitters signal end of 198kHz, home of BBC's Test
Match Special and Today in Parliament
Long wave transmission's days are numbered.
A handful of specially crafted glass valves each measuring one metre high
are all that is stopping the historic home of Test Match Special, Yesterday
in Parliament and the Daily Service going suddenly and permanently off air.
BBC Radio 4 long wave, which transmits on the 198 kilohertz frequency,
relies on ageing transmitter equipment that uses a pair of the valves - no
longer manufactured - to function.
The valves, at Droitwitch in Worcestershire, are so rare that engineers say
there are fewer than 10 in the world, and the BBC has been forced to buy up
the entire global supply. Each lasts anywhere between one and 10 years, and
when one of the last two blows the service will go quiet.
Last week, Mark Thompson, the director-general of the BBC, signalled the
beginning of the end for the 198 long-wave service, which is still used by
90,000 homes in Britain to receive Radio 4 in areas where short-range FM
does not penetrate.
Aware of the public sensitivity - the service fought off a closure threat in
the early 1990s - Thompson promised that Radio 4 long wave would "find a new
home" on both analogue FM and digital radio once suitable frequencies could
be found.
Denis Nowlan, the network manager for Radio 4, said: "This is technology
that is becoming obsolete. Digital radio now reaches 97% of the population,
and there is plenty time to find new homes for long wave-only programmes."
Radio 4 was traditionally broadcast on long wave, using frequencies used by
the BBC since the 1930s, but the station has long been aired on FM and
digital radio and online. More recently, the long-wave service has been used
to carry a handful of traditional programmes deemed unsuitable for FM, while
the range of the long-wave signal also ensured that ships could pick up
shipping forecasts.
The best-known programme broadcast on long wave is Test Match Special, which
would otherwise dominate vast chunks of the Radio 4 schedule. Yesterday in
Parliament airs when Westminster is sitting at 8.30am, cutting out the last
30 minutes of Today on FM, while Radio 4's Christian worship programme, the
Daily Service, is carried every weekday at 9.45am.
So antique is the transmission equipment that the BBC does not believe it is
possible to manufacture new valves because slightly faulty replacements
could cause a catastrophic failure of the other parts of the transmitter.
Whenever the valves fail a dangerous "arc of power" surges through the 700ft
Droitwitch transmission masts.
Building a new long-wave transmitter for Radio 4 would cost "many millions
of pounds", according to BBC insiders. Part of the problem is that pumping
the signal so that it can cover England, Wales and lowland Scotland requires
500 kilowatts of power, far more than other long wave transmitters, which
makes the kit both unique and expensive. Meanwhile, modern mariners use
other technology and services to get forecast information.
Highland Scotland is covered by two smaller transmitters and Northern
Ireland does not easily receive Radio 4 long wave. However, the signal is
strong enough to be audible in parts of the Netherlands, Ireland, France and
Germany.
The BBC began national transmission with the National Programme, the
predecessor of Radio 4, in 1926. Transmission moved to 200 kilohertz in
1934, when the BBC moved its transmission to Droitwitch, and has remained at
that frequency, allowing for a slight shift to 198Khz ever since.
Built under the leadership of Sir John Reith, his last act as
director-general after being forced out in 1938 was to personally close down
the National Programme at Drotwitch before signing the visitors' book and
leaving.